PDF DOWNLOAD: Nuvera N1800V36 N1821V36 N1800V48 N1824V48 Fuel Cell Diagnostic Troubleshooting Manual

Diagnostic Troubleshooting Manual Fuel Cell System

31009693 | 07/2023

NOTICE OF PROPRIETARY PROPERTY This document and the information contained in it are the proprietary property of Nuvera Fuel Cells LLC. This document is intended solely for the internal use of the recipient and may not be used outside the recipient's organization nor distributed to third parties without the express prior written consent of Nuvera Fuel Cells LLC.

© Nuvera Fuel Cells, LLC. 2023 All rights reserved.

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Nuvera® Fuel Cell System Diagnostic Troubleshooting Manual

Contents

Table of Contents Diagnostic troubleshooting codes DTC 516112 (FMI 31) (0x7E010)-Battery contactor, close. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 Diagnose and troubleshoot DTC 516112. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .7 DTC 516113 (FMI 17) (0x7E011)-Battery SOC low. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10 Diagnose and troubleshoot DTC 516113. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10 DTC 516113 (FMI 18) (0x7E011)-Battery SOC low. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12 Diagnose and troubleshoot DTC 516113. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12 DTC 516113 (FM 1) (0x7E011)-Battery SOC critically low. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .14 Diagnose and troubleshoot DTC 516113. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14 DTC 516113 (FMI 0) (0x7E011)-Battery SOC critically high. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16 Diagnose and troubleshoot DTC 516113. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16 DTC 516113 (FMI 16) (0x7E011)-Battery SOC high. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18 Diagnose and troubleshoot DTC 516113. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18 DTC 516114 (FMI 0) (0x7E012)-Battery cell voltage critically high. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20 Diagnose and troubleshoot DTC 516114. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20 DTC 516114 (FM 16) (0x7E012)-Battery cell voltage high. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21 Diagnose and troubleshoot DTC 516114. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21 DTC 516114 (FMI 18) (0x7E012)-Battery cell voltage low. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22 Diagnose and troubleshoot DTC 516114. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22 DTC 516114 (FMI 1) (0x7E012)-Battery cell voltage critically low. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23 Diagnose and troubleshoot DTC 516114. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23 DTC 516115 (FM 0) (0x7E013)-Battery cell temperature critically high. . . . . . . . . . . . . . . . . . . . . . . . . .24 Diagnose and troubleshoot DTC 516115. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24 DTC 516115 (FM 16) (0x7E013)-Battery cell temperature high. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25 Diagnose and troubleshoot DTC 516115. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25 DTC 516115 (FM 15) (0x7E013)-Battery cell temperature moderately high. . . . . . . . . . . . . . . . . . . . . 26 Diagnose and troubleshoot DTC 516115. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26 DTC 516115 (FMI 18) (0x7E013)-Battery cell temperature low. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27 Diagnose and troubleshoot DTC 516115. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27 DTC 516115 (FMI 1) (0x7E013)-Battery cell temperature critically low. . . . . . . . . . . . . . . . . . . . . . . . . .28 Diagnose and troubleshoot DTC 516115. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28 DTC 516116 (FM 31) (0x7E014)-BMS fault. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29 Diagnose and troubleshoot DTC 516116. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29 DTC 516117 (FMI 31) (0x7E015)-BMS Communication error. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30 Diagnose and troubleshoot DTC 516117. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30 DTC 516128 (FM 1) (0x7E020)-Tank pressure critically low. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32 Diagnose and troubleshoot DTC 516128. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32 I

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Diagnostic troubleshooting codes DTC 516128 (FMI 18) (0x7E020)-Tank pressure low. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34 Diagnose and troubleshoot DTC 516128. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34 DTC 516145 (FMI 0) (0x7E031)-FCS stack, anode pressure critically high. . . . . . . . . . . . . . . . . . . . . . . . 36 Diagnose and troubleshoot DTC 516145. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36 DTC 516145 (FMI 16) (0x7E031)-FCS stack, anode pressure high. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .39 Diagnose and troubleshoot DTC 516145. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39 DTC 516145 (FMI 1) (0x7E031)-FCS stack, anode pressure critically low. . . . . . . . . . . . . . . . . . . . . . . . 42 Diagnose and troubleshoot DTC 516145 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42 DTC 516145 (FMI 18) (0x7E031)-FCS stack, anode pressure low. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45 Diagnose and troubleshoot DTC 516145. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45 DTC 516146 (FMI 31) (0x7E032)-DCDC Converter, Current mismatch error. . . . . . . . . . . . . . . . . . . . . 48 Diagnose and troubleshoot DTC 516146. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48 DTC 516147 (FMI 31) (0x7E033)-DCDC Converter, Communication error. . . . . . . . . . . . . . . . . . . . . . . 49 Diagnose and troubleshoot DTC 516147. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 49 DTC 516148 (FMI 31) (0x7E034)-DCDC Converter, Forward enable fault. . . . . . . . . . . . . . . . . . . . . . . . 50 Diagnose and troubleshoot DTC 516148. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50 DTC 516149 (FMI 0) (0x7E035)-FCS Stack temperature critically high. . . . . . . . . . . . . . . . . . . . . . . . . . .51 Diagnose and troubleshoot DTC 516149. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 51 DTC 516149 (FMI 16) (0x7E035)-FCS Stack temperature high. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .53 Diagnose and troubleshoot DTC 516149. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 53 DTC 516150 (FMI 0) (0x7E036)-FCS Stack cell voltage critically high. . . . . . . . . . . . . . . . . . . . . . . . . . . . 55 Diagnose and troubleshoot DTC 516150. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 55 DTC 516150 (FMI 16) (0x7E036)-FCS Stack cell voltage high. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 57 Diagnose and troubleshoot DTC 516150. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 57 DTC 516150 (FMI 1) (0x7E036)-FCS Stack cell voltage critically low. . . . . . . . . . . . . . . . . . . . . . . . . . . . .59 Diagnose and troubleshoot DTC 516150. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 59 DTC 516150 (FMI 18) (0x7E036)-FCS Stack cell voltage low. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 61 Diagnose and troubleshoot DTC 516150. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 61 DTC 516152 (FMI 0) (0x7E038)-FCS Stack Coolant pressure critically low. . . . . . . . . . . . . . . . . . . . . . . 63 Diagnose and troubleshoot DTC 516152. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 63 DTC 516152 (FMI 18) (0x7E038)-FCS Stack Coolant pressure low. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 64 Diagnose and troubleshoot DTC 516152. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 64 DTC 516176 (FMI 31) (0x7E050)-Coolant system, pump controller communication error. . . . . . . . . 65 Diagnose and troubleshoot DTC 516176. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 65 DTC 516177 (FMI 4) (0x7E051)-Coolant system, Stack inlet temp. voltage low or shorted to ground.

66 Diagnose and troubleshoot DTC 516177. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 66

II

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Diagnostic troubleshooting codes DTC 516177 (FMI 3) (0x7E051)-Coolant system, Stack inlet temp. voltage high or shorted to high source. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 67 Diagnose and troubleshoot DTC 516177. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 67 DTC 516178 (FMI 4) (0x7E052)-Coolant system, Stack outlet temp. voltage low or shorted to ground . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 68 Diagnose and troubleshoot DTC 516178. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 68 DTC 516178 (FMI 3) (0x7E052)-Coolant system, Stack outlet temp. voltage high or shorted to high source. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 69 Diagnose and troubleshoot DTC 516178. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 69 DTC 516192 (FMI 31) (0x7E060)-Cathode system, compressor controller communication error. . . 71 Diagnose and troubleshoot DTC 516192. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 71 DTC 516193 (FMI 31) (0x7E061)-Cathode system, flow measurement error. . . . . . . . . . . . . . . . . . . . . 73 Diagnose and troubleshoot DTC 516193. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 73 DTC 516097 (FMI 31) (0x7E001)-Distributed IO, Communication error. . . . . . . . . . . . . . . . . . . . . . . . . 75 Diagnose and troubleshoot DTC 516097 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 75 DTC 516098 (FMI 0) (0x7E002) or 516100 (FMI 0) (0x7E004)-LFL critically high. . . . . . . . . . . . . . . . . . 76 Diagnose and troubleshoot DTC 516098 or DTC 516100. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .76 DTC 516098 (FMI 16) (0x7E002) or 516100 (FMI 16) (0x7E004)-LFL high. . . . . . . . . . . . . . . . . . . . . . . . 77 Diagnose and troubleshoot DTC 516098 (Sensor 1) or 516100 (Sensor 2). . . . . . . . . . . . . . . . . . . .77 DTC 516098 (FMI 15) (0x7E002) or 516100 (FMI 15) (0x7E004)-LFL above normal range. . . . . . . . . .78 Diagnose and troubleshoot DTC 516098 (Sensor 1) or 516100 (Sensor 2). . . . . . . . . . . . . . . . . . . .78 DTC 516098 (FHI 3) (0x7E002) or 516100 (FHI 3) (0x7E004)-LFL high or shorted to high source. . . . 79 Diagnose and troubleshoot DTC 516098 (Sensor 1) or 516100 (Sensor 2). . . . . . . . . . . . . . . . . . . .79 DTC 516098 (FMI 4) (0x7E002) or 516100 (FMI 4) (0x7E004)-LFL low or shorted to low source. . . . 80 Diagnose and troubleshoot DTC 516098 (Sensor 1) or 516100 (Sensor 2). . . . . . . . . . . . . . . . . . . .80 DTC 516098 (FMI 12) (0x7E002) or 516100 (FMI 12) (0x7E004)-LFL Bad intelligent device or component. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 81 Diagnose and troubleshoot DTC 516098 (Sensor 1) or 516100 (Sensor 2). . . . . . . . . . . . . . . . . . . .81 DTC 516098 (FMI 14) (0x7E002) or 516100 (FMI 14) (0x7E004)-Special instructions. . . . . . . . . . . . . . 82 Diagnose and troubleshoot DTC 516098 (Sensor 1) or 516100 (Sensor 2). . . . . . . . . . . . . . . . . . . .82 DTC 516096 (FMI 31) (0x7E000)-E-stop active. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 83 Diagnose and troubleshoot DTC 516096. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 83 DTC 516099 (FMI 31)-SWS Loop Fault. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 85 Diagnose and troubleshoot DTC 516099. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 85 Observed symptoms FCS will not turn on. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 86 Observed issue:. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 86 III

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Observed symptoms Possible cause. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 86 Observed issue:. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 86 Possible cause. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 86 Possible cause. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 86 Possible cause. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 87 FCS On, No DTC-No voltage from the main contactor. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 87 Observed issue:. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 87 Possible cause. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 87 Possible cause. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 87 Solution. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .87 Possible cause. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 87 Solution. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .87 Observed issue:. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 88 Possible cause. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 88 Possible cause. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 88 Solution. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .88 Possible cause. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 88 Solution. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .88 Possible cause. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 89 Solution. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .89 FCS is on, Fuel gauge does not function properly. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 89 Observed issue:. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 89 Possible cause. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 89 Observed issue:. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 91 Possible cause. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 91 Observed issue:. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 91 Possible cause. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 91 Observed issue:. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 91 FCS does not transmit data. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 91 Observed issue:. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 91 Possible cause. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 92 Observed issue:. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 92 Possible cause. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 92 Possible cause. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 92 Observed issue:. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 92 Possible cause. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 92 Observed issue:. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 93 Possible cause. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 93 IV

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Nuvera® Fuel Cell System Diagnostic Troubleshooting Manual

Contents

Observed symptoms Possible cause. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 93 Possible cause. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 93 Excessive noise. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 93 Observed issue:. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 93 Possible cause. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 93 Odor/Smoke/Sparks/Flame. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 95 Observed issue:. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 95 Possible causes. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 95 Fluids leaking from FCS. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 96 Observed issue:. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 96 Possible causes. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 96 Piping and instrumentation and wiring diagrams Wiring diagrams. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 98 ESS harness diagrams. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 106 Piping and instrumentation diagram. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 109

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Nuvera® Fuel Cell System Diagnostic Troubleshooting Manual

Contents

List of Figures Figure 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27

Title

Page

Fuse F7. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 Fuse F3. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9 Fuses. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38 Fuses. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41 Fuses. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44 Fuses. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47 Fuse holders. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 71 Motor controller and main battery. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 74 Compressor connector. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 74 E-stop backshell. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 84 HMI connector. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 90 Sheet 1 of 8. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .98 Sheet 2 of 8. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .99 Sheet 3 of 8. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 100 Sheet 4 of 8. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 101 Sheet 5 of 8. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 102 Sheet 6 of 8. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 103 Sheet 7 of 8. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 104 Sheet 8 of 8. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 105 Type 1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 106 Type 2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 106 Type 3. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 107 Type 4. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 107 Type 5. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 108 Type 6. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 108 Sheet 1 of 2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 111 Sheet 2 of 2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 113

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Nuvera® Fuel Cell System Diagnostic Troubleshooting Manual

Diagnostic troubleshooting codes

DTC 516112 (FMI 31) (0x7E010)-Battery contactor, close Tripping conditions Main output voltage supply is < 15V sensed at the STW.1 after 15 seconds of the intended closure of the main battery contactor.

Action Shutdown Activation states Always

Diagnose and troubleshoot DTC 516112 1. Test voltage of 12V SLA 5ah battery. Is voltage above 12.3V? YES - Proceed to Step 2.

NO - Replace the battery.

2.

Check for power to the STW. • Verify the fuse associated with the 12V SLA positive terminal (F7 on main PCB) is not open. See Figure 1.

• Verify continuity between STW harness (31009893) connector (red) and 12V SLA positive terminal (red).

• Verify continuity between STW harness connector (black) and 12V SLA negative terminal (black).

3.

Does DTC 516112 still occurr?

YES - Proceed to Step 4.

NO - Return FCS to operation.

4.

Check for control signal at the battery contactor coil.

• Verify continuity between STW harness connector pin 42 (red, 14AWG wire) and battery contactor connector pin E1.2 of 840-10127-01 (red).

• Verify continuity between 12V SLA negative terminal and battery contactor connector pin E1.1 of J1 harness (31009952) (black), with E-stop button disabled.

• Disconnect the battery contactor connector and main controller connector (STW) to access the pins of the circuit.

5.

Does DTC 516112 still occurr?

YES - Proceed to Step 4.

NO - Return FCS to operation.

6.

Check for voltage feedback to controller.

• Verify the fuse associated with the 24V input to STW (F3 on main PCB) is not open. See Figure 2.

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Nuvera® Fuel Cell System Diagnostic Troubleshooting Manual

Diagnostic troubleshooting codes

DTC 516112 (FMI 31) (0x7E010)-Battery contactor, close (continued) Diagnose and troubleshoot DTC 516112 (continued) • While system is powered on, verify battery terminal voltage, as measured at the battery terminals, is between 21.0V and 29.4V. If no voltage is found at output terminals, replace the battery and contact HYG for more assistance.

• Verify continuity between STW harness (red) and large output terminal of battery contactor (side with red 12 AWG wire).

• Verify voltage at both large output terminals of the battery contactor. Use the 12V SLA negative terminal (black) as a ground reference. When the contactor is closed, both terminals will have battery voltage present.

7.

If DTC 516112 still triggers, contact HYG for assistance.

Figure 1. Fuse F7

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Nuvera® Fuel Cell System Diagnostic Troubleshooting Manual

Diagnostic troubleshooting codes

DTC 516112 (FMI 31) (0x7E010)-Battery contactor, close (continued) Diagnose and troubleshoot DTC 516112 (continued)

Figure 2. Fuse F3

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Nuvera® Fuel Cell System Diagnostic Troubleshooting Manual

Diagnostic troubleshooting codes

DTC 516113 (FMI 17) (0x7E011)-Battery SOC low Tripping conditions FMI 17: Battery is below normal operating range-least severe Battery SOC is below 25% Action Shutdown Activation states Always

Diagnose and troubleshoot DTC 516113 1. Average output load may be higher than the system can provide. With the FCS running, reduce the average load or allow the unit to idle until the battery is recharged.

NOTE: Recharge rate drops significantly over 60% State of Charge in the internal battery, but recharge rate will increase aggressively as SOC drops to 50% or lower.

2.

Is fuel cell system charging the battery?

YES - Proceed to Step 3.

NO - Verify the hydrogen tank is filled to more than 400 psi. Turn the lift truck off and restart the FCS. If DTC still occurs, proceed to Step 7.

3.

Are there other DTC's related to fuel cell or fuel management triggering?

NOTE: If there are diagnostic codes related to the fuel cell/fuel management, correct them before investigating andy battery SOC issues.

YES - Follow the procedure to troubleshoot the DTC. Proceed to Step 4. Continue to troubleshoot the SOC. NO - Return FCS to operation.

4.

Check the if the battery contactor has failed in closed position 1.

Turn the FCS OFF.

2.

Measure the voltage at the connector between USER.1 (GND) and USER.12 (12Vc).

• If over 13.5V, the contactor is most likely stuck ON. • If under 13.0V, the contactor is most likely OPEN. 3.

Additional checks:

CAUTION The following step exposes the technician to a potential high-current discharge if probes slip or a short occurs. Be careful when performing this step.

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Nuvera® Fuel Cell System Diagnostic Troubleshooting Manual

Diagnostic troubleshooting codes

DTC 516113 (FMI 17) (0x7E011)-Battery SOC low (continued) Diagnose and troubleshoot DTC 516113 (continued) • Open the top panel and measure for voltage between the “24V” and “GND” terminals on the main PCB. If voltage is detected, the main battery contactor is stuck ON and must be replaced.

See Nuvera® Fuel Cell System Service Manual for procedure.

5.

Has battery contactor failed in the closed position?

YES - Disconnet the ground busbar from the battery. Replace the contactor immediately. See Nuvera® Fuel Cell System Service Manual for procedure. Do not allow the battery to reach < 5% SOC. NO - Proceed to Step 6.

WARNING If the battery reaches 0% SOC (or below 3V/cell open circuit), it must be replaced.

DO NOTuse a battery after it has discharged below 3 V/cell or 0% SOC due to the increased risk of fire or failure.

6.

Does DTC 516113 still occur?

YES - Replace the 12V battery.

NO - Return FCS to operation.

7.

If DTC 516113 still triggers, contact HYG for assistance.

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Nuvera® Fuel Cell System Diagnostic Troubleshooting Manual

Diagnostic troubleshooting codes

DTC 516113 (FMI 18) (0x7E011)-Battery SOC low Tripping conditions FMI 18: Battery is below normal operating range-moderately severe Battery SOC is below 20% Action Shutdown Activation states Always

Diagnose and troubleshoot DTC 516113 1. Average output load may be higher than the system can provide. With the FCS running, reduce the average load or allow the unit to idle until the battery is recharged.

NOTE: Recharge rate drops significantly over 60% State of Charge in the internal battery, but recharge rate will increase aggressively as SOC drops to 50%or lower.

2.

Is fuel cell system charging the battery?

YES - Proceed to Step 3.

NO - Verify the hydrogen tank is filled to more than 400 psi. Turn the lift truck off and restart the FCS. If DTC still occurs, proceed to Step 7.

3.

Are there other DTC's related to fuel cell or fuel management triggering?

NOTE: If there are diagnostic codes related to the fuel cell/fuel management, correct them before investigating andy battery SOC issues.

YES - Follow the procedure to troubleshoot the DTC. Proceed to Step 4. Continue to troubleshoot the SOC. NO - Return FCS to operation.

4.

Check the if the battery contactor has failed in closed position.

1.

Turn the FCS OFF.

2.

Measure the voltage at the connector between USER.1 (GND) and USER.12 (12Vc).

• If over 13.5V, the contactor is most likely stuck ON. • If under 13.0V, the contactor is most likely OPEN. 3.

Additional checks:

CAUTION The following step exposes the technician to a potential high-current discharge if probes slip or a short occurs. Be careful when performing this step.

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Nuvera® Fuel Cell System Diagnostic Troubleshooting Manual

Diagnostic troubleshooting codes

DTC 516113 (FMI 18) (0x7E011)-Battery SOC low (continued) Diagnose and troubleshoot DTC 516113 (continued) • Open the top panel and measure for voltage between the “24V” and “GND” terminals on the main PCB. If voltage is detected, the main battery contactor is stuck ON and must be replaced.

See Nuvera® Fuel Cell System Service Manual for procedure.

5.

Has battery contactor failed in the closed position?

YES - Disconnet the ground busbar from the battery. Replace the contactor immediately. See Nuvera® Fuel Cell System Service Manual for procedure. Do not allow the battery to reach < 5% SOC. NO - Proceed to Step 6.

WARNING If the battery reaches 0% SOC (or below 3V/cell open circuit), it must be replaced.

DO NOTuse a battery after it has discharged below 3 V/cell or 0% SOC due to the increased risk of fire or failure.

6.

Does DTC 516113 still occur?

YES - Replace the 12V battery.

NO - Return FCS to operation.

7.

If DTC 516113 still triggers, contact HYG for assistance.

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Nuvera® Fuel Cell System Diagnostic Troubleshooting Manual

Diagnostic troubleshooting codes

DTC 516113 (FM 1) (0x7E011)-Battery SOC critically low Tripping conditions FMI 1: Battery is below normal operating range-most severe Battery SOC is below 5% Action Immediate shutdown Activation states Always

Diagnose and troubleshoot DTC 516113 1. Average output load may be higher than the system can provide. With the FCS running, reduce the average load or allow the unit to idle until the battery is recharged.

NOTE: Recharge rate drops significantly over 60% State of Charge in the internal battery, but recharge rate will increase aggressively as SOC drops to 50%or lower.

2.

Is fuel cell system charging the battery?

YES - Proceed to Step 3.

NO - Verify the hydrogen tank is filled to more than 400 psi. Turn the lift truck off and restart the FCS. If DTC still occurs, proceed to Step 7.

3.

Are there other DTC's related to fuel cell or fuel management triggering?

NOTE: If there are diagnostic codes related to the fuel cell/fuel management, correct them before investigating andy battery SOC issues.

YES - Follow the procedure to troubleshoot the DTC. Proceed to Step 4. Continue to troubleshoot the SOC. NO - Return FCS to operation.

4.

Check the if the battery contactor has failed in closed position 1.

Turn the FCS OFF.

2.

Measure the voltage at the connector between USER.1 (GND) and USER.12 (12Vc).

• If over 13.5V, the contactor is most likely stuck ON. • If under 13.0V, the contactor is most likely OPEN. 3.

Additional checks:

CAUTION The following step exposes the technician to a potential high-current discharge if probes slip or a short occurs. Be careful when performing this step.

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Nuvera® Fuel Cell System Diagnostic Troubleshooting Manual

Diagnostic troubleshooting codes

DTC 516113 (FM 1) (0x7E011)-Battery SOC critically low (continued) Diagnose and troubleshoot DTC 516113 (continued) • Open the top panel and measure for voltage between the “24V” and “GND” terminals on the main PCB. If voltage is detected, the main battery contactor is stuck ON and must be replaced.

See Nuvera® Fuel Cell System Service Manual for procedure.

5.

Has battery contactor failed in the closed position?

YES - Disconnet the ground busbar from the battery. Replace the contactor immediately. See Nuvera® Fuel Cell System Service Manual for procedure. Do not allow the battery to reach < 5% SOC. NO - Proceed to Step 6.

WARNING If the battery reaches 0% SOC (or below 3V/cell open circuit), it must be replaced.

DO NOTuse a battery after it has discharged below 3 V/cell or 0% SOC due to the increased risk of fire or failure.

6.

Does DTC 516113 still occur?

YES - Replace the 12V battery.

NO - Return FCS to operation.

7.

If DTC 516113 still triggers, contact HYG for assistance.

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Nuvera® Fuel Cell System Diagnostic Troubleshooting Manual

Diagnostic troubleshooting codes

DTC 516113 (FMI 0) (0x7E011)-Battery SOC critically high Tripping conditions FMI 0: Battery is above normal operating range-most severe Battery SOC is above 99% Action Shutdown Activation states Always

Diagnose and troubleshoot DTC 516113 1. Average output load may be higher than the system can provide. With the FCS running, reduce the average load or allow the unit to idle until the battery is recharged.

NOTE: Recharge rate drops significantly over 60% State of Charge in the internal battery, but recharge rate will increase aggressively as SOC drops to 50%or lower.

2.

Is fuel cell system charging the battery?

YES - Proceed to Step 3.

NO - Verify the hydrogen tank is filled to more than 400 psi. Turn the lift truck off and restart the FCS. If DTC still occurs, proceed to Step 7.

3.

Are there other DTC's related to fuel cell or fuel management triggering?

NOTE: If there are diagnostic codes related to the fuel cell/fuel management, correct them before investigating andy battery SOC issues.

YES - Follow the procedure to troubleshoot the DTC. Proceed to Step 4. Continue to troubleshoot the SOC. NO - Return FCS to operation.

4.

Check the if the battery contactor has failed in closed position 1.

Turn the FCS OFF.

2.

Measure the voltage at the connector between USER.1 (GND) and USER.12 (12Vc).

• If over 13.5V, the contactor is most likely stuck ON. • If under 13.0V, the contactor is most likely OPEN. 3.

Additional checks:

CAUTION The following step exposes the technician to a potential high-current discharge if probes slip or a short occurs. Be careful when performing this step.

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Diagnostic troubleshooting codes

DTC 516113 (FMI 0) (0x7E011)-Battery SOC critically high (continued) Diagnose and troubleshoot DTC 516113 (continued) • Open the top panel and measure for voltage between the “24V” and “GND” terminals on the main PCB. If voltage is detected, the main battery contactor is stuck ON and must be replaced.

See Nuvera® Fuel Cell System Service Manual for procedure.

5.

Has battery contactor failed in the closed position?

YES - Disconnet the ground busbar from the battery. Replace the contactor immediately. See Nuvera® Fuel Cell System Service Manual for procedure. Do not allow the battery to reach < 5% SOC. NO - Proceed to Step 6.

WARNING If the battery reaches 0% SOC (or below 3V/cell open circuit), it must be replaced.

DO NOTuse a battery after it has discharged below 3 V/cell or 0% SOC due to the increased risk of fire or failure.

6.

Does DTC 516113 still occur?

YES - Replace the 12V battery.

NO - Return FCS to operation.

7.

If DTC 516113 still triggers, contact HYG for assistance.

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Diagnostic troubleshooting codes

DTC 516113 (FMI 16) (0x7E011)-Battery SOC high Tripping conditions FMI 16: Battery is above normal operating range-least severe Battery SOC is above 95% Action Warning Reset Clears when SOC is below threshold.

Diagnose and troubleshoot DTC 516113 1. Average output load may be higher than the system can provide. With the FCS running, reduce the average load or allow the unit to idle until the battery is recharged.

NOTE: Recharge rate drops significantly over 60% State of Charge in the internal battery, but recharge rate will increase aggressively as SOC drops to 50%or lower.

2.

Is fuel cell system charging the battery?

YES - Proceed to Step 3.

NO - Verify the hydrogen tank is filled to more than 400 psi. Turn the lift truck off and restart the FCS. If DTC still occurs, proceed to Step 7.

3.

Are there other DTC's related to fuel cell or fuel management triggering?

NOTE: If there are diagnostic codes related to the fuel cell/fuel management, correct them before investigating andy battery SOC issues.

YES - Follow the procedure to troubleshoot the DTC. Proceed to Step 4. Continue to troubleshoot the SOC. NO - Return FCS to operation.

4.

Check the if the battery contactor has failed in closed position 1.

Turn the FCS OFF.

2.

Measure the voltage at the connector between USER.1 (GND) and USER.12 (12Vc).

• If over 13.5V, the contactor is most likely stuck ON. • If under 13.0V, the contactor is most likely OPEN. 3.

Additional checks:

CAUTION The following step exposes the technician to a potential high-current discharge if probes slip or a short occurs. Be careful when performing this step.

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Diagnostic troubleshooting codes

DTC 516113 (FMI 16) (0x7E011)-Battery SOC high (continued) Diagnose and troubleshoot DTC 516113 (continued) • Open the top panel and measure for voltage between the “24V” and “GND” terminals on the main PCB. If voltage is detected, the main battery contactor is stuck ON and must be replaced.

See Nuvera® Fuel Cell System Service Manual for procedure.

5.

Has battery contactor failed in the closed position?

YES - Disconnet the ground busbar from the battery. Replace the contactor immediately. See Nuvera® Fuel Cell System Service Manual for procedure. Do not allow the battery to reach < 5% SOC. NO - Proceed to Step 6.

WARNING If the battery reaches 0% SOC (or below 3V/cell open circuit), it must be replaced.

DO NOTuse a battery after it has discharged below 3 V/cell or 0% SOC due to the increased risk of fire or failure.

6.

Does DTC 516113 still occur?

YES - Replace the 12V battery.

NO - Return FCS to operation.

7.

If DTC 516113 still triggers, contact HYG for assistance.

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Diagnostic troubleshooting codes

DTC 516114 (FMI 0) (0x7E012)-Battery cell voltage critically high Tripping conditions FMI 0: Battery cell voltage is above normal operating range-most severe Battery cell voltage is above 4.2V for 0.5 seconds.

Reaction System faults and immediately shuts down all systems Activation states Always Reset Clears after a power cycle

Diagnose and troubleshoot DTC 516114 1. Check for internal fault by using the PC Service Tool (PCST) to test battery cell voltage. Is the minimum/maximum battery cell voltage difference > 200m?

YES - Replace the battery. See Nuvera® Fuel Cell System Service Manual for procedure. Return the battery to the manufacturer. Contact HYG for assistance.

NO - Proceed to Step 2.

2.

Battery temperature is less than 5°C (41 F°). Is battery internal PTC heater functioning properly?

YES - Proceed to Step 3.

NO - Replace the 24V Battery and return to HYG.

3.

Was the battery left in a cold environment without power?

YES - Allow the battery to warm to 10°C (50 F°). Contact the manufacturer for assistance if problems persist due to exposure to excessive cold temperatures.

NO - Proceed to Step 4.

4.

Battery may be overcharged. Is SoC > 90%?

NOTE: If the FCS is being overworked and experiencing heavy or extended regen events from the truck, discuss the application for fuel cell systems with the manufacturer.

YES - Replace the battery. See Nuvera® Fuel Cell System Service Manual for procedure. Return the battery to the manufacturer. Contact HYG for assistance.

NO - Proceed to Step 5.

5.

The battery may have reached End of Life. Replace the battery and return to manufacturer for disposal.

6.

If DTC 516114 still triggers, contact HYG for assistance.

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Diagnostic troubleshooting codes

DTC 516114 (FM 16) (0x7E012)-Battery cell voltage high Tripping conditions FMI 16: Battery cell voltage is above normal operating range-moderately severe Battery cell voltage is above 4.0V for 1 second.

Action Warning Activation states Always Reset Clears when cell voltage is below threshold.

Diagnose and troubleshoot DTC 516114 1. Check for internal fault by using the PC Service Tool (PCST) to test battery cell voltage. Is the minimum/maximum battery cell voltage difference > 200m?

YES - Replace the battery. See Nuvera® Fuel Cell System Service Manual for procedure. Return the battery to the manufacturer. Contact HYG for assistance.

NO - Proceed to Step 2.

2.

Battery temperature is less than 5°C (41 F°). Is battery internal PTC heater functioning properly?

YES - Proceed to Step 3.

NO - Replace the 24V Battery and return to HYG.

3.

Was the battery left in a cold environment without power?

YES - Allow the battery to warm to 10°C (50 F°). Contact the manufacturer for assistance if problems persist due to exposure to excessive cold temperatures.

NO - Proceed to Step 4.

4.

Battery may be overcharged. Is SoC > 90%?

NOTE: If the FCS is being overworked and experiencing heavy or extended regen events from the truck, discuss the application for fuel cell systems with the manufacturer.

YES - Replace the battery. See Nuvera® Fuel Cell System Service Manual for procedure. Return the battery to the manufacturer. Contact HYG for assistance.

NO - Proceed to Step 5.

5.

The battery may have reached End of Life. Replace the battery and return to manufacturer for disposal.

6.

If DTC 516114 still triggers, contact HYG for assistance.

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Diagnostic troubleshooting codes

DTC 516114 (FMI 18) (0x7E012)-Battery cell voltage low Tripping conditions FMI 18: Battery cell voltage is below normal operating range-moderately severe Battery cell voltage is above 3.0V for 1 second.

Action Warning Activation states Always Reset Clears when cell voltage is above threshold.

Diagnose and troubleshoot DTC 516114 1. Check for internal fault by using the PC Service Tool (PCST) to test battery cell voltage. Is the minimum/maximum battery cell voltage difference > 200m?

YES - Replace the battery. See Nuvera® Fuel Cell System Service Manual for procedure. Return the battery to the manufacturer. Contact HYG for assistance.

NO - Proceed to Step 2.

2.

Battery temperature is less than 5°C (41 F°). Is battery internal PTC heater functioning properly?

YES - Proceed to Step 3.

NO - Replace the 24V Battery and return to HYG.

3.

Was the battery left in a cold environment without power?

YES - Allow the battery to warm to 10°C (50 F°). Contact the manufacturer for assistance if problems persist due to exposure to excessive cold temperatures.

NO - Proceed to Step 4.

4.

Battery may be undercharged. Is SoC < 30%?

There may be a heavy current drawn during low SoC periods.

YES - Limit truck maximun power draw while at low battery voltages. Ensure the application average power is low enough for the FCS. Stack current will be 60A+ and SoC will drop close to min SoC limit with high power draw. Replace the battery. Verify battery impedance is low enough for application.

NO - Proceed to Step 5.

5.

The battery may have reached End of Life. Replace the battery and return to manufacturer for disposal.

6.

If DTC 516114 still triggers, contact HYG for assistance.

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Diagnostic troubleshooting codes

DTC 516114 (FMI 1) (0x7E012)-Battery cell voltage critically low Tripping conditions FMI 1: Battery cell voltage is below normal operating range-most severe Battery cell voltage is below 2.5V for 0.5 seconds.

Action Immediate shutdown Activation states Always Reset Clears after a power cycle

Diagnose and troubleshoot DTC 516114 1. Check for internal fault by using the PC Service Tool (PCST) to test battery cell voltage. Is the minimum/maximum battery cell voltage difference > 200m?

YES - Replace the battery. See Nuvera® Fuel Cell System Service Manual for procedure. Return the battery to the manufacturer. Contact HYG for assistance.

NO - Proceed to Step 2.

2.

Battery temperature is less than 5°C (41 F°). Is battery internal PTC heater functioning properly?

YES - Proceed to Step 3.

NO - Replace the 24V Battery and return to HYG.

3.

Was the battery left in a cold environment without power?

YES - Allow the battery to warm to 10°C (50 F°). Contact the manufacturer for assistance if problems persist due to exposure to excessive cold temperatures.

NO - Proceed to Step 4.

4.

Battery may be undercharged. Is SoC < 30%?

There may be a heavy current drawn during low SoC periods.

YES - Limit truck maximun power draw while at low battery voltages. Ensure the application average power is low enough for the FCS. Stack current will be 60A+ and SoC will drop close to min SoC limit with high power draw. Replace the battery. Verify battery impedance is low enough for application.

NO - Proceed to Step 5.

5.

The battery may have reached End of Life. Replace the battery and return to manufacturer for disposal.

6.

If DTC 516114 still triggers, contact HYG for assistance.

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Diagnostic troubleshooting codes

DTC 516115 (FM 0) (0x7E013)-Battery cell temperature critically high Tripping conditions FMI 0: Battery cell temperature is above normal operating range-most severe Battery cell temperature is above 55°C (131 °F).

Action Shutdown Activation states Always Reset Clears whe cell temperature is below threshold.

Diagnose and troubleshoot DTC 516115 1. Check if regen is too high. Is charge current on the application load > 200A for 10 seconds or > 130A continuously?

YES - Excessive heating of the battery may have occurred. Reduce the regen current and try again.

NO - Proceed to Step 2.

2.

Was FCS used in a high temperature environment?

YES - If FCS is operating in temperatures higher than 38°C (100 °F) for extended periods of time, remove the FCS from the environment and allow to cool.

NO - Proceed to Step 3.

3.

Is the battery cooling inlet or outlet obstructed?

YES - Clean as necessary.

NO - Proceed to Step 4.

4.

Is battery internal temperature indicating > 200°C (392° F)?

YES - Replace the battery. See Nuvera® Fuel Cell System Service Manual. Return the battery to the manufacturer. Contact HYG for assistance.

NO - Proceed to Step 5.

5.

If DTC 516115 still triggers, contact HYG for assistance.

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Diagnostic troubleshooting codes

DTC 516115 (FM 16) (0x7E013)-Battery cell temperature high Tripping conditions FMI 16: Battery cell temperature is above normal operating range-moderately severe Battery cell temperature is above 52°C (126 °F) Action Thermal Derate - Limited Operation Activation states Always Reset Clears when cell temperature is 2° (36°F)

Diagnose and troubleshoot DTC 516115 1. Check if regen is too high. Is charge current on the application load > 200A for 10 seconds or > 130A continuously?

YES - Excessive heating of the battery may have occurred. Reduce the regen current and try again.

NO - Proceed to Step 2.

2.

Was FCS used in a high temperature environment?

YES - If FCS is operating in temperatures higher than 38°C (100°F) for extended periods of time, remove the FCS from the environment and allow to cool.

NO - Proceed to Step 3.

3.

Is the battery cooling inlet or outlet obstructed?

YES - Clean as necessary.

NO - Proceed to Step 4.

4.

Is battery internal temperature indicating > 200°C (392° F)?

YES - Replace the battery. See Nuvera® Fuel Cell System Service Manual. Return the battery to the manufacturer. Contact HYG for assistance.

NO - Proceed to Step 5.

5.

If DTC 516115 still triggers, contact HYG for assistance.

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Diagnostic troubleshooting codes

DTC 516115 (FM 15) (0x7E013)-Battery cell temperature moderately high Tripping conditions FMI 15: Battery cell temperature is above normal operating range-least severe.

Battery cell temperature is above 46°C (115°F).

Action Warning Activation states Always Reset Clears when cell temperature is 2° (36°F) below threshold.

Diagnose and troubleshoot DTC 516115 1. Is DTC being triggered as a result of significantly heavy usage period?

YES - Ignore, unless this DTC occurs frequently.

NO - Proceed to Step 2.

2.

Check if regen is too high. Is charge > 200A for 10 seconds or > 130A continuously?

YES - Excessive heating of the battery may have occurred. Reduce the regen current and try again.

NO - Proceed to Step 3.

3.

Was FCS used in a high temperature environment?

YES - If FCS is operating in temperatures higher than 38°C (100°F) for extended periods of time, remove the FCS from the environment and allow to cool.

NO - Proceed to Step 4.

4.

Is the battery cooling inlet or outlet obstructed?

YES - Clean as necessary.

NO - Proceed to Step 5.

5.

Does battery internal fault indicate > 200°C (392°F)?

YES - Replace the battery. See Nuvera® Fuel Cell System Service Manual.

NO - Proceed to Step 6.

6.

If DTC 516115 still triggers, contact HYG for assistance.

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Diagnostic troubleshooting codes

DTC 516115 (FMI 18) (0x7E013)-Battery cell temperature low Tripping conditions FMI 18: Battery cell temperature is below normal operating range-moderately severe Battery cell temperature is below 0°C (32°F).

Action Thermal Derate ramp start Activation states Always Reset Clears when cell temperature is above threshold.

Diagnose and troubleshoot DTC 516115 1. Was the FCS stored in a freezing environment?

YES - Remove the FCS from the freezing environment. FCS is not rated for use in below freezing environments.

NO - Proceed to Step 2.

2.

Is battery internal temperature indicating > 200°C (392° F)?

YES - Replace the battery. See Nuvera® Fuel Cell System Service Manual for procedure. Return the battery to the manufacturer. Contact HYG for assistance.

NO - Proceed to Step 3.

3.

Is the battery cooling inlet or outlet obstructed?

YES - Clean as necessary.

NO - Proceed toStep 4.

4.

If DTC 516115 still triggers, contact HYG for assistance.

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Diagnostic troubleshooting codes

DTC 516115 (FMI 1) (0x7E013)-Battery cell temperature critically low Tripping conditions FMI 1: Battery cell temperature is below normal operating range-most severe Battery cell temperature is below -10°C (14°F) Action Thermal Derate 0%, Limited Operation Activation states Always Reset Clears when cell temperature is above threshold

Diagnose and troubleshoot DTC 516115 1. Was the FCS stored in a freezing environment?

YES - Remove the FCS from the freezing environment. FCS is not rated for use in below freezing environments.

NO - Proceed to Step 2.

2.

Is battery internal temperature indicating > 200°C (392° F)?

YES - Replace the battery. See Nuvera® Fuel Cell System Service Manual for procedure. Return the battery to the manufacturer. Contact HYG for assistance.

NO - Proceed to Step 3.

3.

Is the battery cooling inlet or outlet obstructed?

YES - Clean as necessary.

NO - Proceed to Step 4.

4.

If DTC 516115 still triggers, contact HYG for assistance.

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Diagnostic troubleshooting codes

DTC 516116 (FM 31) (0x7E014)-BMS fault Tripping conditions FMI 31: BMS internal battery has triggered error/alarm Action Immediate shutdown. Remains in Fault mode (12V lead acid battery only for datalogging) for 5 min or until power off using E-stop or power button.

Activation states Always Reset Clears after a power cycle.

Diagnose and troubleshoot DTC 516116 1. Is battery voltage out of range high or low?

YES - Inspect the battery contactor, and replace if fused. Replace battery if voltage at terminals is less than 20V or greater than 30V. SeeNuvera® Fuel Cell System Service Manual for procedure.

NO - Proceed to Step 2.

2.

Is there a battery internal fault?

YES - Verify the terminal voltage is between 21V-29.4V. Replace the battery and contact manufacturer. See Nuvera® Fuel Cell System Service Manual.

NO - Proceed to Step 3.

3.

Is battery internal temperature below or above allowable range (-20°C to 55°C (-4° F to 131°F))?

YES - See the applicable procedure in this manual for troubleshooting high or low battery temperature. Follow procedure.

NO - Proceed to Step 4.

4.

Is there an internal BMU fault or failure?

YES - Replace the battery and contact manufacturer. See Nuvera® Fuel Cell System Service Manual.

NO - Proceed to Step 5.

5.

Is there an internal wiring fault?

YES - Replace the battery and contact manufacturer. See Nuvera® Fuel Cell System Service Manual.

NO - Proceed to Step 6.

6.

If DTC 516116 still triggers, contact HYG for assistance.

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Diagnostic troubleshooting codes

DTC 516117 (FMI 31) (0x7E015)-BMS Communication error Tripping conditions FMI 31: BMS is not responding via CAN for > 1 second (10 samples) Action System faults (SWS active) and shuts all systems down within 30 seconds.

Activation states Always Reset Clears after a power cycle.

Diagnose and troubleshoot DTC 516117 1. Is the BMS powered?

YES - Proceed to Step 5.

NO - Proceed to Step 2.

2.

Is the connector for the battery properly seated?

YES - Proceed to Step 3.

NO - Fully seat the connector. Recycle power and wait for startup.

3.

Is the connector from the battery harness to the main PCB connector properly seated?

YES - Proceed to Step 4.

NO - Fully seat the connector. Recycle power and wait for startup.

4.

Check for voltage on Battery Connector (C2) immediately after startup.

• Use pin 4 on the 12-pin Battery Connector (C2) for ground.

• Confirm pin 3 and pin 7 on the 12-pin Battery Connector (C2) are +12V_sw.

5.

Is BMS communicating?

YES - Proceed to Step 8.

NO - Check for continuity between C2 pin 1 and STW.7. Check for continuity between C2 pin 2 and STW.26. Proceed to Step 6.

6.

Check for CAN bus fault. With FCS powered off, measure the resistance of CAN1 on the user connector. Measure the resistance of CAN1 on the 12-pin Battery Connector (C2) pins 1 and 2. Is the resistance 55-65 Ohms?

YES - Proceed to Step 7.

NO - Repair the CAN bus. Proceed to Step 8.

7.

Is there a battery internal fault?

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Diagnostic troubleshooting codes

DTC 516117 (FMI 31) (0x7E015)-BMS Communication error (continued) Diagnose and troubleshoot DTC 516117 (continued) YES - Replace the battery and contact the manufacturer. See Nuvera® Fuel Cell System Service Manual.

NO - Repair the CAN bus. Proceed to Step 8.

8.

If DTC 516117 still triggers, contact HYG for assistance.

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Diagnostic troubleshooting codes

DTC 516128 (FM 1) (0x7E020)-Tank pressure critically low Tripping conditions FMI 1: Tank pressure is below 400 psi Action Fuel cell charging system is shutdown. Lift lockout is engaged. Battery continues to operate.

Activation states Always Reset Clears when fill data port is disconnected and pressure is above threshold.

Diagnose and troubleshoot DTC 516128 1. Is hydrogen fuel level low?

YES - Refill tank with hyddrogen. See Fueling the Nuvera® Fuel Cell System in Nuvera® Fuel Cell System Operating Manual for procedure.

NO - Proceed to Step 2.

2.

Perform a leak check of the hydrogen plumbing system. See Nuvera® Fuel Cell System Service Manual for procedure.

3.

Is a hydrogen fuel leak detected in the plumbing or hardware?

YES - Repair any leaks. See Nuvera® Fuel Cell System Service Manual.

NO - Proceed to Step 4.

4.

Check for faulty wiring between AS1 sensor and the controller.

• Verify continuity between STW.28 of STW wire harness (P/N 31009893) and AS4.B of lower cable assembly (P/N 31009952).

• Verify AS4.B of 840-10126-02 is not shorted to ground or 12V. • When powered on, verify AS4.A of 31009952 is 12V. Use the 12V SLA negative terminal (black) as a ground reference.

5.

Is wiring faulty?

YES - Correct wiring issues. Restart FCS and wait for startup.

NO - Proceed to Step 6.

6.

Check AS1 sensor to confirm it is functioning properly.

• Use 4-20mA adapter harness for testing.

• When powered on, measure current on AS4.B of 31009952. The measured current should be between 4 mA and 20 mA.

7.

Is AS1 sensor functioning properly?

YES - Proceed to Step 8.

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Diagnostic troubleshooting codes

DTC 516128 (FM 1) (0x7E020)-Tank pressure critically low (continued) Diagnose and troubleshoot DTC 516128 (continued) NO - Replace the AS1 sensor. See Nuvera® Fuel Cell System Service Manual.

8.

If DTC 516128 still triggers, contact HYG for assistance.

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Diagnostic troubleshooting codes

DTC 516128 (FMI 18) (0x7E020)-Tank pressure low Tripping conditions FMI 18: Tank pressure is below 1000 psi Action HMI indicates low fuel with yellow flashing fuel gauge and intermittent audible tone.

Activation states Always Reset Clears when pressure is above threshold.

Diagnose and troubleshoot DTC 516128 1. Is hydrogen fuel level low?

YES - Refill tank with hyddrogen. See Fueling the Nuvera® Fuel Cell System in Nuvera® Fuel Cell System Operating Manual for procedure.

NO - Proceed to Step 2.

2.

Perform a leak check of the hydrogen plumbing system. See Nuvera® Fuel Cell System Service Manual for procedure.

3.

Is a hydrogen fuel leak detected in the plumbing or hardware?

YES - Repair any leaks. See Nuvera® Fuel Cell System Service Manual.

NO - Proceed to Step 4.

4.

Check for faulty wiring between AS1 sensor and the controller.

• Verify continuity between STW.28 of STW wire harness (P/N 31009893) and AS4.B of lower cable assembly (31009952).

• Verify AS4.B of 31009952 is not shorted to ground or 12V. • When powered on, verify AS4.A of 31009952 is 12V. Use the 12V SLA negative terminal (black) as a ground reference.

5.

Is wiring faulty?

YES - Correct wiring issues. Restart FCS and wait for startup.

NO - Proceed to Step 6.

6.

Check AS1 sensor to confirm it is functioning properly.

• Use 4-20mA adapter harness for testing.

• When powered on, measure current on AS4.B of 31009952. The measured current should be between 4 mA and 20 mA.

7.

Is AS1 sensor functioning properly?

YES - Proceed to Step 8.

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Diagnostic troubleshooting codes

DTC 516128 (FMI 18) (0x7E020)-Tank pressure low (continued) Diagnose and troubleshoot DTC 516128 (continued) NO - Replace the AS1 sensor. See Nuvera® Fuel Cell System Service Manual.

8.

If DTC 516128 still triggers, contact HYG for assistance.

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Diagnostic troubleshooting codes

DTC 516145 (FMI 0) (0x7E031)-FCS stack, anode pressure critically high Tripping conditions FMI 0: Reactant cross pressure is above 56 kPa above cathode inlet pressurefor 2s.

Action Fuel cell charging system is shutdown. Lift lockout is engaged. Battery continues to operate.

Activation states Always Reset Clears after a power cycle.

Diagnose and troubleshoot DTC 516145 1. Check if the hydrogen regulator is functioning properly.

Is the regulator set to 35-45 kPa as sensed in PCST or Telemetry?

YES - Proceed to Step 2.

NO - Adjust the regulator to the correct pressure.

2.

Is regulator regulating with less than 5 kPa of “ripple” as determined by watching PCST or Telemetry?

YES - Proceed to Step 3.

NO - Replace the regulator. See Nuvera® Fuel Cell System Service Manual for procedure.

3.

Check if the hydrogen supply valve is malfunctioning.

• Tank and stack solenoids will be warm to the touch when operating correctly. If very hot or room temperature, solenoid may have a wiring or internal fault.

• Check connector integrity. Confirm pins are fully seated in the connector. Confirm the connector is fully seated and latched to the solenoid.

• Check the wiring circuit from the solenoid to the Master Controller. Verify the circular bulkhead connector is fully seated.

• Check the 24V supply fuses on the main PCB. See Figure 3.

4.

Is hydrogen fuel level low?

YES - Refill tank with hyddrogen. See Fueling the Nuvera® Fuel Cell System in Nuvera® Fuel Cell System Operating Manual for procedure.

NO - Proceed to Step 5.

5.

Perform a leak check of the hydrogen plumbing system. See Nuvera® Fuel Cell System Service Manual for procedure.

6.

Is a hydrogen fuel leak detected in the plumbing or hardware?

YES - Repair any leaks. See Nuvera® Fuel Cell System Service Manual. Verify operation.

NO - Proceed to Step 7.

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Diagnostic troubleshooting codes

DTC 516145 (FMI 0) (0x7E031)-FCS stack, anode pressure critically high (continued) Diagnose and troubleshoot DTC 516145 (continued) 7.

Check the wiring between AS1 sensor and the STW controller.

NOTE: Use the 12V SLA negative terminal (black) as a ground reference.

• Verify continuity between pin 67 of the 81-pin STW harness (P/N 31009893) and AS1.A (solenoid) of lower cab (P/N 31009952).

• Verify AS1.A (solenoid) of 31009952 is not shorted to ground or 12V. • When powered on, verify AS1.B of 31009952 is > 5V while connected and enabled (current regulated by master controller).

• Is wiring functioning properly?

YES - Proceed to Step 8.

NO - Fix any faults in the wiring. See Nuvera® Fuel Cell System Service Manual.

8.

Check AS1 sensor to confirm it is functioning properly.

• Use 4-20mA adapter harness for testing.

• When powered on, measure current on AS4.B of 31009952. The measured current should be between 4 mA and 20 mA.

9.

Is AS1 sensor functioning properly?

• Use debug harness to verify current for pressure sensors.

• When powered on, measure current on AS1.A of 31009952. The measured current should be between 4 mA and 20 mA. YES - Proceed to Step 10.

NO - Replace the AS1 sensor. See Nuvera® Fuel Cell System Service Manual.

10. If DTC 516145 still triggers, contact HYG for assistance.

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Diagnostic troubleshooting codes

DTC 516145 (FMI 0) (0x7E031)-FCS stack, anode pressure critically high (continued) Diagnose and troubleshoot DTC 516145 (continued)

Figure 3. Fuses 1.

F3

2.

F6

3.

38

F7

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Nuvera® Fuel Cell System Diagnostic Troubleshooting Manual

Diagnostic troubleshooting codes

DTC 516145 (FMI 16) (0x7E031)-FCS stack, anode pressure high Tripping conditions FMI 16: Reactant cross pressure is above 50 kPa for 1 second.

Action No impact Activation states Always Activation states Clears when pressure is below threshold.

Diagnose and troubleshoot DTC 516145 1. Check if the hydrogen regulator is functioning properly.

Is the regulator set to 35-45 kPa as sensed in PCST or Telemetry?

YES - Proceed to Step 2.

NO - Adjust the regulator to the correct pressure.

2.

Is regulator regulating with less than 5 kPa of “ripple” as determined by watching PCST or Telemetry?

YES - Proceed to Step 3.

NO - Replace the regulator. See Nuvera® Fuel Cell System Service Manual for procedure.

3.

Check if the hydrogen supply valve is malfunctioning.

• Tank and stack solenoids will be warm to the touch when operating correctly. If very hot or room temperature, solenoid may have a wiring or internal fault.

• Check connector integrity. Confirm pins are fully seated in the connector. Confirm the connector is fully seated and latched to the solenoid.

• Check the wiring circuit from the solenoid to the Master Controller. Verify the circular bulkhead connector is fully seated.

• Check the 24V supply fuses on the main PCB. See Figure 4.

4.

Is hydrogen fuel level low?

YES - Refill tank with hyddrogen. See Fueling the Nuvera® Fuel Cell System in Nuvera® Fuel Cell System Operating Manual for procedure.

NO - Proceed to Step 5.

5.

Perform a leak check of the hydrogen plumbing system. See Nuvera® Fuel Cell System Service Manual for procedure.

6.

Is a hydrogen fuel leak detected in the plumbing or hardware?

YES - Repair any leaks. See Nuvera® Fuel Cell System Service Manual. Verify operation.

NO - Proceed to Step 7.

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Diagnostic troubleshooting codes

DTC 516145 (FMI 16) (0x7E031)-FCS stack, anode pressure high (continued) Diagnose and troubleshoot DTC 516145 (continued) 7.

Check the wiring between AS1 sensor and the STW controller.

NOTE: Use the 12V SLA negative terminal (black) as a ground reference.

• Verify continuity between pin 67 of the 81-pin STW harness (P/N 31009893) and AS1.A (solenoid) of lower cable (P/N 31009952).

• Verify AS1.A (solenoid) of 31009952 is not shorted to ground or 12V. • When powered on, verify AS1.B of 31009952 is > 5V while connected and enabled (current regulated by master controller).

• Is wiring functioning properly?

YES - Proceed to Step 8.

NO - Fix any faults in the wiring. See Nuvera® Fuel Cell System Service Manual.

8.

Check AS1 sensor to confirm it is functioning properly.

• Use 4-20mA adapter harness for testing.

• When powered on, measure current on AS4.B of 31009952. The measured current should be between 4 mA and 20 mA.

9.

Is AS1 sensor functioning properly?

• Use debug harness to verify current for pressure sensors.

• When powered on, measure current on AS1.A of 31009952. The measured current should be between 4 mA and 20 mA. YES - Proceed to Step 10.

NO - Replace the AS1 sensor. See Nuvera® Fuel Cell System Service Manual.

10. If DTC 516145 still triggers, contact HYG for assistance.

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Diagnostic troubleshooting codes

DTC 516145 (FMI 16) (0x7E031)-FCS stack, anode pressure high (continued) Diagnose and troubleshoot DTC 516145 (continued)

Figure 4. Fuses 1.

F3

2.

F6

3.

41

F7

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Nuvera® Fuel Cell System Diagnostic Troubleshooting Manual

Diagnostic troubleshooting codes

DTC 516145 (FMI 1) (0x7E031)-FCS stack, anode pressure critically low Tripping conditions FMI 1: Reactant cross pressure below the minimum threshold for 2s. Minimum threshold is a linear function based on stack current, from 7kPa at 0A to 23kPa at 300A. Action Fuel cell charging system is shutdown. Lift lockout is engaged. Battery continues to operate.

Activation states Always Reset Clears after a power cycle.

Diagnose and troubleshoot DTC 516145 1. Check if the hydrogen regulator is functioning properly.

Is the regulator set to 35-45 kPa as sensed in PCST or Telemetry?

YES - Proceed to Step 2.

NO - Adjust the regulator to the correct pressure.

2.

Is regulator regulating with less than 5 kPa of “ripple” as determined by watching PCST or Telemetry?

YES - Proceed to Step 3.

NO - Replace the regulator. See Nuvera® Fuel Cell System Service Manual for procedure.

3.

Check if the hydrogen supply valve is malfunctioning.

• Tank and stack solenoids will be warm to the touch when operating correctly. If very hot or room temperature, solenoid may have a wiring or internal fault.

• Check connector integrity. Confirm pins are fully seated in the connector. Confirm the connector is fully seated and latched to the solenoid.

• Check the wiring circuit from the solenoid to the Master Controller. Verify the circular bulkhead connector is fully seated.

• Check the 24V supply fuses on the main PCB. See Figure 5.

4.

Is hydrogen fuel level low?

YES - Refill tank with hyddrogen. See Fueling the Nuvera® Fuel Cell System in Nuvera® Fuel Cell System Operating Manual for procedure.

NO - Proceed to Step 5.

5.

Perform a leak check of the hydrogen plumbing system. See Nuvera® Fuel Cell System Service Manual for procedure.

6.

Is a hydrogen fuel leak detected in the plumbing or hardware?

YES - Repair any leaks. See Nuvera® Fuel Cell System Service Manual. Verify operation.

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DTC 516145 (FMI 1) (0x7E031)-FCS stack, anode pressure critically low (continued) Diagnose and troubleshoot DTC 516145 (continued) NO - Proceed to Step 7.

7.

Check the wiring between AS1 sensor and the STW controller.

NOTE: Use the 12V SLA negative terminal (black) as a ground reference.

• Verify continuity between pin 67 of the 81-pin STW harness (P/N 31009893) and AS1.A (solenoid) of lower cable (P/N 31009952).

• Verify AS1.A (solenoid) of 31009952 is not shorted to ground or 12V. • When powered on, verify AS1.B of 31009952 is > 5V while connected and enabled (current regulated by master controller).

• Is wiring functioning properly?

YES - Proceed to Step 8.

NO - Fix any faults in the wiring. See Nuvera® Fuel Cell System Service Manual.

8.

Check AS1 sensor to confirm it is functioning properly.

• Use 4-20mA adapter harness for testing.

• When powered on, measure current on AS4.B of 31009952. The measured current should be between 4 mA and 20 mA.

9.

Is AS1 sensor functioning properly?

• Use debug harness to verify current for pressure sensors.

• When powered on, measure current on AS1.A of 31009952. The measured current should be between 4 mA and 20 mA. YES - Proceed to Step 10.

NO - Replace the AS1 sensor. See Nuvera® Fuel Cell System Service Manual.

10. If DTC 516145 still triggers, contact HYG for assistance.

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Diagnostic troubleshooting codes

DTC 516145 (FMI 1) (0x7E031)-FCS stack, anode pressure critically low (continued) Diagnose and troubleshoot DTC 516145 (continued)

Figure 5. Fuses 1.

F3

2.

F6

3.

44

F7

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Nuvera® Fuel Cell System Diagnostic Troubleshooting Manual

Diagnostic troubleshooting codes

DTC 516145 (FMI 18) (0x7E031)-FCS stack, anode pressure low Tripping conditions Reactant cross pressure below the minimum threshold (same value as FMI 1) for 5s Action No impact Activation states Always Reset Clears when pressure is above threshold.

Diagnose and troubleshoot DTC 516145 1. Check if the hydrogen regulator is functioning properly.

Is the regulator set to 35-45 kPa as sensed in PCST or Telemetry?

YES - Proceed to Step 2.

NO - Adjust the regulator to the correct pressure.

2.

Is regulator regulating with less than 5 kPa of “ripple” as determined by watching PCST or Telemetry?

YES - Proceed to Step 3.

NO - Replace the regulator. See Nuvera® Fuel Cell System Service Manual for procedure.

3.

Check if the hydrogen supply valve is malfunctioning.

• Tank and stack solenoids will be warm to the touch when operating correctly. If very hot or room temperature, solenoid may have a wiring or internal fault.

• Check connector integrity. Confirm pins are fully seated in the connector. Confirm the connector is fully seated and latched to the solenoid.

• Check the wiring circuit from the solenoid to the Master Controller. Verify the circular bulkhead connector is fully seated.

• Check the 24V supply fuses on the main PCB. See Figure 6.

4.

Is hydrogen fuel level low?

YES - Refill tank with hyddrogen. See Fueling the Nuvera® Fuel Cell System in Nuvera® Fuel Cell System Operating Manual for procedure.

NO - Proceed to Step 5.

5.

Perform a leak check of the hydrogen plumbing system. See Nuvera® Fuel Cell System Service Manual for procedure.

6.

Is a hydrogen fuel leak detected in the plumbing or hardware?

YES - Repair any leaks. See Nuvera® Fuel Cell System Service Manual. Verify operation.

NO - Proceed to Step 7.

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Diagnostic troubleshooting codes

DTC 516145 (FMI 18) (0x7E031)-FCS stack, anode pressure low (continued) Diagnose and troubleshoot DTC 516145 (continued) 7.

Check the wiring between AS1 sensor and the STW controller.

NOTE: Use the 12V SLA negative terminal (black) as a ground reference.

• Verify continuity between pin 67 of the 81-pin STW harness (P/N 31009893) and AS1.A (solenoid) of lower cable (P/N 31009952).

• Verify AS1.A (solenoid) of 31009952 is not shorted to ground or 12V. • When powered on, verify AS1.B of 31009952 is > 5V while connected and enabled (current regulated by master controller).

• Is wiring functioning properly?

YES - Proceed to Step 8.

NO - Fix any faults in the wiring. See Nuvera® Fuel Cell System Service Manual.

8.

Check AS1 sensor to confirm it is functioning properly.

• Use 4-20mA adapter harness for testing.

• When powered on, measure current on AS4.B of 31009952. The measured current should be between 4 mA and 20 mA.

9.

Is AS1 sensor functioning properly?

• Use debug harness to verify current for pressure sensors.

• When powered on, measure current on AS1.A of 31009952. The measured current should be between 4 mA and 20 mA. YES - Proceed to Step 10.

NO - Replace the AS1 sensor. See Nuvera® Fuel Cell System Service Manual.

10. If DTC 516145 still triggers, contact HYG for assistance.

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Diagnostic troubleshooting codes

DTC 516145 (FMI 18) (0x7E031)-FCS stack, anode pressure low (continued) Diagnose and troubleshoot DTC 516145 (continued)

Figure 6. Fuses 1.

F3

2.

F6

3.

47

F7

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Diagnostic troubleshooting codes

DTC 516146 (FMI 31) (0x7E032)-DCDC Converter, Current mismatch error Tripping conditions FMI 31: The difference between the input current and the maximum input current from the stack to the DCDC converter exceeds 10A for 2s.

Action No impact Activation states Always Reset Clears when current difference is below threshold.

Diagnose and troubleshoot DTC 516146 1. Check all electrical connections on the DCDC converter. Are any connectors loose or not fully seated?

YES - Fully connect and reseat connectors. Restart FCS and wait for startup.

NO - Proceed to Step 2.

2.

Are bus bars and fasteners loose?

YES - Retorque fasteners. See Nuvera® Fuel Cell System Service Manual for procedure. Restart FCS and wait for startup.

NO - Proceed to Step 3.

3.

Use PCST to check for a mismatch between “Input Current” and "Max Input Current Command" of more than 3A. Does DC/DC have a faulty output channel?

YES - Replace faulty DCDC board if condition prevents system from maintaining Battery SoC. See Nuvera® Fuel Cell System Service Manual for procedure.

NO - Proceed to Step 4.

4.

If DTC 516146 still triggers contact HYG for assistance.

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Diagnostic troubleshooting codes

DTC 516147 (FMI 31) (0x7E033)-DCDC Converter, Communication error Tripping conditions FMI 31: DCDC converter is not responding via CAN Action Fuel cell charging system will not work. Lift lockout is engaged. Battery continues to operate until Battery, SOC (0x7E011h) is trigged.

Activation states Always Reset Clears after apower cycle.

Diagnose and troubleshoot DTC 516147 1. Verify DCDC is powered on. Are the LED's on the DCDC control PCB on?

YES - Proceed to Step 2.

NO - Measure the voltage between C1 pin 5 and C1 pin 6 of DCDC harness (P/N 31009894). The measured voltage should be 12-14 Vdc. Identify and repair faulty wire between DCDC Connector and Main PCB. 2.

Check if CANbus is functioning properly.

• With the FCS completely powered down, use a multimeter to verify the CAN bus is connected and properly terminated. Measured resistance between C1 pin 1 and C pin 2 of DCDC harness (P/N 31009894) should be 120 Ohms or less. Verify there is no continuity between the CAN wires, C1 pin 1 and C1 pin 2, and the power/ground wires, C1 pin 5 and C1 pin 6.

• Verify continuity of the CAN wires between the DCDC and the STW. Measure continuity from C1.1 (yellow) of DCDC harness (P/N 31009894) to pin 7 of the 81-pin connector on the STW harness (P/N 31009893). Measure continuity from C1.2 (green) of DCDC harness (P/N 31009894) to STW.26 (green) of STW harness (P/N 31009893).

Is CANbus functioning properly?

YES - Replace the DCDC. See Nuvera® Fuel Cell System Service Manual for procedure. Restart FCS and wait for startup.

NO - Repair CANbus wiring and restart unit.

3.

If DTC 516147 still triggers, contact HYG for assistance.

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Diagnostic troubleshooting codes

DTC 516148 (FMI 31) (0x7E034)-DCDC Converter, Forward enable fault Tripping conditions FMI 31: The input current to the DCDC converter is greater than 2 A while DCDC is NOT enabled.

Action Warning. FCS will not charge. Battery will continue to operate. Lift Lockout is engaged.

Activation states Always Reset Clears after a power cycle.

Diagnose and troubleshoot DTC 516148 1. Check all electrical connections on FCS stack power harness for loose connections and/or shorts. Are any connectors loose or not fully seated?

YES - Fully connect and reseat connectors, or repair wire as needed. Restart FCS and wait for startup.

NO - Proceed to Step 2.

2.

Does DTC 516148 occur soon after the supply valve to the stack is opened?

YES - Inspect the stack for physical damage. See Nuvera® Fuel Cell System Service Manual for procedure. Restart FCS and wait for startup.

NO - Proceed to Step 3.

3.

Check for failure of the DCDC power board? Is the power board malfunctioning?

YES - Remove the DCDC and replace with new. See Nuvera® Fuel Cell System Service Manual for procedure. Return the faulty DCDC to manufacturer and contact HYG. NO - Proceed to Step 4.

4.

If DTC 516148 still triggers, contact HYG for assistance.

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Diagnostic troubleshooting codes

DTC 516149 (FMI 0) (0x7E035)-FCS Stack temperature critically high Tripping conditions FMI 0: Stack temperature is above 75°C (167°F) Action Shutdown. Lift lockout is engaged. Battery continues to operate.

Activation states Always Reset Clears after a power cycle

Diagnose and troubleshoot DTC 516149 1. Check the level of coolant in the radiator. Is coolant low?

YES - Add coolant. See Nuvera® Fuel Cell System Service Manual for procedure.

NO - Proceed to Step 2.

2.

Use the Nuvera® Fuel Cell System Serice Tool to confirm the coolant pump is functioning properly?

YES - Proceed to Step 3.

NO - Replace the coolant pump. See Nuvera® Fuel Cell System Service Manual

3.

Check for blockages in the cooling lines. Are cooling lines blocked?

YES - Remove the blockage or replace the cooling line. See Nuvera® Fuel Cell System Service Manual for procedure.

NO - Proceed to Step 4.

4.

Verify the radiator fan is working properly. Does the fan turn for 5 seconds at initial startup?

YES - Proceed to Step 5.

NO - Remove and replace the fan. See Nuvera® Fuel Cell System Service Manual.

5.

Check for power at the radiator • If the radiator fan does not turn during startup, check that there is 24V power to pins RAD_FAN.1 and RAD_FAN.2 of P/N 31009954.

• Also check that the reference command generates a voltage greater than 0V when the fan is commanded to run (With unit off, insert meter positive probe into pin RAD_FAN.4 of 31009954 and negative to ground bar. Start unit and watch for change in voltage).

• If 24V is not present, check fuse STFB_25A from power harness (P/N 31009899).

6.

Check to confirm temperature sensor is functioning properly.

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Diagnostic troubleshooting codes

DTC 516149 (FMI 0) (0x7E035)-FCS Stack temperature critically high (continued) Diagnose and troubleshoot DTC 516149 (continued) • Unplug the sensor LS4 (at the coolant port of the stack outlet manifold) and measure the resistanceacross the sensor. Resistance should be greater than 1.0 kΩ (if hot) and less than 12.5 kΩ (if very cold). For reference, the resistance should be approximately 2 kΩ –4.7 kΩ at room temperature. If the measured resistance is abnormal compared to these values, replace the sensor.

7.

Is temperature sensor functioning properly?

YES - Proceed to Step 8.

NO - Replace the sensor. See Nuvera® Fuel Cell System Service Manual for procedure.

8.

If DTC 516149 still triggers, contact HYG for assistance.

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Diagnostic troubleshooting codes

DTC 516149 (FMI 16) (0x7E035)-FCS Stack temperature high Tripping conditions FMI 16: Stack temperature is above 72°C (162°F) Action No impact.

Activation states Always Reset Clears when stack temperature is below threshold.

Diagnose and troubleshoot DTC 516149 1. Check the level of coolant in the radiator. Is coolant low?

YES - Add coolant. See Nuvera® Fuel Cell System Service Manual for procedure.

NO - Proceed to Step 2.

2.

Use the Nuvera® Fuel Cell System Serice Tool to confirm the coolant pump is functioning properly?

YES - Proceed to Step 3.

NO - Replace the coolant pump. See Nuvera® Fuel Cell System Service Manual

3.

Check for blockages in the cooling lines. Are cooling lines blocked?

YES - Remove the blockage or replace the cooling line. See Nuvera® Fuel Cell System Service Manual for procedure.

NO - Proceed to Step 4.

4.

Verify the radiator fan is working properly. Does the fan turn for 5 seconds at initial startup?

YES - Proceed to Step 5.

NO - Remove and replace the fan. See Nuvera® Fuel Cell System Service Manual.

5.

Check for power at the radiator • If the radiator fan does not turn during startup, check that there is 24V power to pins RAD_FAN.1 and RAD_FAN.2 of P/N 31009954.

• Also check that the reference command generates a voltage greater than 0V when the fan is commanded to run (With unit off, insert meter positive probe into pin RAD_FAN.4 of P/N 31009954 and negative to ground bar. Start unit and watch for change in voltage).

• If 24V is not present, check fuse STFB_25A from power harness P/N 31009899.

6.

Check to confirm temperature sensor is functioning properly.

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Diagnostic troubleshooting codes

DTC 516149 (FMI 16) (0x7E035)-FCS Stack temperature high (continued) Diagnose and troubleshoot DTC 516149 (continued) • Unplug the sensor LS4 (at the coolant port of the stack outlet manifold) and measure the resistanceacross the sensor. Resistance should be greater than 1.0 kΩ (if hot) and less than 12.5 kΩ (if very cold). For reference, the resistance should be approximately 2 kΩ –4.7 kΩ at room temperature. If the measured resistance is abnormal compared to these values, replace the sensor.

7.

Is temperature sensor functioning properly?

YES - Proceed to Step 5.

NO - Replace the sensor. See Nuvera® Fuel Cell System Service Manual for procedure.

8.

If DTC 516149 still triggers, contact HYG for assistance.

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Diagnostic troubleshooting codes

DTC 516150 (FMI 0) (0x7E036)-FCS Stack cell voltage critically high Tripping conditions FMI 0: Fuel cell average cell voltage is above 1.05 V for 2 seconds Action Fuel cell charging system is shutdown. Lift lockout is engaged. Battery continues to operate.

Activation states Always Reset Clears after a power cycle.

Diagnose and troubleshoot DTC 516150 1. Confirm that the DCDC is functioning. Are there any DTC's related to the DCDC currently triggering?

YES - See the procedure to troubleshoot the appropriate DTC. NO - Proceed to Step 2.

2.

Check wiring at the stack and DCDC electrical connectors. Are all connections properly connected and seated?

YES - Proceed to Step 3.

NO - Fully connect and seat all connectors. Repair crimps and wires if needed.

3.

Air flow to the fuel cell system may be impeded. Check the air filter for blockages or sediment. Is the air filter blocked?

YES - Remove the blockage. See Nuvera® Fuel Cell System Service Manual for procedure.

NO - Proceed to Step 4.

4.

Is the air filter dirty?

YES - Remove and replace the air filter. See Nuvera® Fuel Cell System Service Manual for procedure.

NO - Proceed to Step 5.

5.

Check air system for visible and audible leaks. Use the PCST to check cathode pressures. Inspect cathode connections around the connection points indicating low pressure and upstream to the previous cathode sensor.

6.

Was air system leak detected?

YES - Proceed to Step 12.

NO - Proceed to Step 7.

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DTC 516150 (FMI 0) (0x7E036)-FCS Stack cell voltage critically high (continued) Diagnose and troubleshoot DTC 516150 (continued) 7.

Check if humidifier is damaged. Use the PCST to verify low FC stack IN/Out cathode pressures while also having high flow out of the exhaust during startup.

8.

Was low cathode pressure detected?

YES - If cathode pressure is low and exhaust flow is high, replace the humidifier. See Nuvera® Fuel Cell System Service Manual.

NO - Proceed to Step 9.

9.

Confirm hydrogen purge feature is functioning properly.

YES - Proceed to Step 10.

NO - Replace the hydrogen purge valve. See Nuvera® Fuel Cell System Service Manual for procedure.

10. Check if hydrogen is being properly supplied to the FCS stack. Perform a leak

check and inspect all plumbing for leaks. See Nuvera® Fuel Cell System Service Manual for procedure.

Was a leak detected?

YES - Identify the location of the leak. Repair or replace hydrogen plumbing as needed. See Nuvera® Fuel Cell System Service Manual.

NO - Proceed to Step 11.

11. Stack may need to be replaced or rebuilt. See Nuvera® Fuel Cell System Service

Manual to remove the stack, and return the stack to manufacturer to be rebuilt.

Contact HYG for assistance.

12. If DTC 516150 still triggers, contact HYG for assistance.

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Diagnostic troubleshooting codes

DTC 516150 (FMI 16) (0x7E036)-FCS Stack cell voltage high Tripping conditions FMI 16: Fuel cell average cell voltage is above 0.95V for 2 seconds Action Warning Activation states Always Reset Clears when average cell voltage is below threshold.

Diagnose and troubleshoot DTC 516150 1. Confirm that the DCDC is functioning. Are there any DTC's related to the DCDC currently triggering?

YES - See the procedure to troubleshoot the appropriate DTC. NO - Proceed to Step 2.

2.

Check wiring at the stack and DCDC electrical connectors. Are all connections properly connected and seated?

YES - Proceed to Step 3.

NO - Fully connect and seat all connectors. Repair crimps and wires if needed.

3.

Air flow to the fuel cell system may be impeded. Check the air filter for blockages or sediment. Is the air filter blocked?

YES - Remove the blockage. See Nuvera® Fuel Cell System Service Manual for procedure.

NO - Proceed to Step 4.

4.

Is the air filter dirty?

YES - Remove and replace the air filter. See Nuvera® Fuel Cell System Service Manual for procedure.

NO - Proceed to Step 5.

5.

Check air system for visible and audible leaks. Use the PCST to check cathode pressures. Inspect cathode connections around the connection points indicating low pressure and upstream to the previous cathode sensor.

6.

Was air system leak detected?

YES - Proceed to Step 12.

NO - Proceed to Step 7.

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DTC 516150 (FMI 16) (0x7E036)-FCS Stack cell voltage high (continued) Diagnose and troubleshoot DTC 516150 (continued) 7.

Check if humidifier is damaged. Use the PCST to verify low FC stack IN/Out cathode pressures while also having high flow out of the exhaust during startup.

8.

Was low cathode pressure detected?

YES - If cathode pressure is low and exhaust flow is high, replace the humidifier. See Nuvera® Fuel Cell System Service Manual.

NO - Proceed to Step 9.

9.

Confirm hydrogen purge feature is functioning properly.

YES - Proceed to Step 10.

NO - Replace the hydrogen purge valve. See Nuvera® Fuel Cell System Service Manual for procedure.

10. Check if hydrogen is being properly supplied to the FCS stack. Perform a leak

check and inspect all plumbing for leaks. See Nuvera® Fuel Cell System Service Manual for procedure.

Was a leak detected?

YES - Identify the location of the leak. Repair or replace hydrogen plumbing as needed. See Nuvera® Fuel Cell System Service Manual.

NO - Proceed to Step 11.

11. Stack may need to be replaced or rebuilt. See Nuvera® Fuel Cell System Service

Manual to remove the stack, and return the stack to manufacturer to be rebuilt.

Contact HYG for assistance.

12. If DTC 516150 still triggers, contact HYG for assistance.

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Diagnostic troubleshooting codes

DTC 516150 (FMI 1) (0x7E036)-FCS Stack cell voltage critically low Tripping conditions FMI 1: Fuel cell average cell voltage is above 0.25V while DCDC is enabled for 2 seconds Action Fuel system shutdown. Lift lockout is engaged. Battery continues to operate Activation states Always Reset Clears after a power cycle

Diagnose and troubleshoot DTC 516150 1. Confirm that the DCDC is functioning. Are there any DTC's related to the DCDC currently triggering?

YES - See the procedure to troubleshoot the appropriate DTC. NO - Proceed to Step 2.

2.

Check wiring at the stack and DCDC electrical connectors. Are all connections properly connected and seated?

YES - Proceed to Step 3.

NO - Fully connect and seat all connectors. Repair crimps and wires if needed.

3.

Air flow to the fuel cell system may be impeded. Check the air filter for blockages or sediment. Is the air filter blocked?

YES - Remove the blockage. See Nuvera® Fuel Cell System Service Manual for procedure.

NO - Proceed to Step 4.

4.

Is the air filter dirty?

YES - Remove and replace the air filter. See Nuvera® Fuel Cell System Service Manual for procedure.

NO - Proceed to Step 5.

5.

Check air system for visible and audible leaks. Use the PCST to check cathode pressures. Inspect cathode connections around the connection points indicating low pressure and upstream to the previous cathode sensor.

6.

Was air system leak detected?

YES - Proceed to Step 12.

NO - Proceed to Step 7.

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Diagnostic troubleshooting codes

DTC 516150 (FMI 1) (0x7E036)-FCS Stack cell voltage critically low (continued) Diagnose and troubleshoot DTC 516150 (continued) 7.

Check if humidifier is damaged. Use the PCST to verify low FC stack IN/Out cathode pressures while also having high flow out of the exhaust during startup.

8.

Was low cathode pressure detected?

YES - If cathode pressure is low and exhaust flow is high, replace the humidifier. See Nuvera® Fuel Cell System Service Manual.

NO - Proceed to Step 9.

9.

Confirm hydrogen purge feature is functioning properly.

YES - Proceed to Step 10.

NO - Replace the hydrogen purge valve. See Nuvera® Fuel Cell System Service Manual for procedure.

10. Check if hydrogen is being properly supplied to the FCS stack. Perform a leak

check and inspect all plumbing for leaks. See Nuvera® Fuel Cell System Service Manual for procedure.

Was a leak detected?

YES - Identify the location of the leak. Repair or replace hydrogen plumbing as needed. See Nuvera® Fuel Cell System Service Manual.

NO - Proceed to Step 11.

11. Stack may need to be replaced or rebuilt. See Nuvera® Fuel Cell System Service

Manual to remove the stack, and return the stack to manufacturer to be rebuilt.

Contact HYG for assistance.

12. If DTC 516150 still triggers, contact HYG for assistance.

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Diagnostic troubleshooting codes

DTC 516150 (FMI 18) (0x7E036)-FCS Stack cell voltage low Tripping conditions FMI 18: Fuel cell average cell voltage is below 0.5V Action Warning Activation states Always Reset Clears when average cell voltage is above threshold.

Diagnose and troubleshoot DTC 516150 1. Confirm that the DCDC is functioning. Are there any DTC's related to the DCDC currently triggering?

YES - See the procedure to troubleshoot the appropriate DTC. NO - Proceed to Step 2.

2.

Check wiring at the stack and DCDC electrical connectors. Are all connections properly connected and seated?

YES - Proceed to Step 3.

NO - Fully connect and seat all connectors. Repair crimps and wires if needed.

3.

Air flow to the fuel cell system may be impeded. Check the air filter for blockages or sediment. Is the air filter blocked?

YES - Remove the blockage. See Nuvera® Fuel Cell System Service Manual for procedure.

NO - Proceed to Step 4.

4.

Is the air filter dirty?

YES - Remove and replace the air filter. See Nuvera® Fuel Cell System Service Manual for procedure.

NO - Proceed to Step 5.

5.

Check air system for visible and audible leaks. Use the PCST to check cathode pressures. Inspect cathode connections around the connection points indicating low pressure and upstream to the previous cathode sensor.

6.

Was air system leak detected?

YES - Proceed to Step 12.

NO - Proceed to Step 7.

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Diagnostic troubleshooting codes

DTC 516150 (FMI 18) (0x7E036)-FCS Stack cell voltage low (continued) Diagnose and troubleshoot DTC 516150 (continued) 7.

Check if humidifier is damaged. Use the PCST to verify low FC stack IN/Out cathode pressures while also having high flow out of the exhaust during startup.

8.

Was low cathode pressure detected?

YES - If cathode pressure is low and exhaust flow is high, replace the humidifier. See Nuvera® Fuel Cell System Service Manual.

NO - Proceed to Step 9.

9.

Confirm hydrogen purge feature is functioning properly.

YES - Proceed to Step 10.

NO - Replace the hydrogen purge valve. See Nuvera® Fuel Cell System Service Manual for procedure.

10. Check if hydrogen is being properly supplied to the FCS stack. Perform a leak

check and inspect all plumbing for leaks. See Nuvera® Fuel Cell System Service Manual for procedure.

Was a leak detected?

YES - Identify the location of the leak. Repair or replace hydrogen plumbing as needed. See Nuvera® Fuel Cell System Service Manual.

NO - Proceed to Step 11.

11. Stack may need to be replaced or rebuilt. See Nuvera® Fuel Cell System Service

Manual to remove the stack, and return the stack to manufacturer to be rebuilt.

Contact HYG for assistance.

12. If DTC 516150 still triggers, contact HYG for assistance.

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Diagnostic troubleshooting codes

DTC 516152 (FMI 0) (0x7E038)-FCS Stack Coolant pressure critically low Tripping conditions FMI 1: Coolant pressure differential between stack inlet and outlet is below 10kPa for 5 seconds Action Shutdown. Lift lockout is engaged. Battery continues to operate.

Activation states Always Reset Clears after a power cycle

Diagnose and troubleshoot DTC 516152 1. Use the Nuvera® Fuel Cell System Serice Tool to confirm the coolant pump is functioning properly?

YES - Proceed to Step 2.

NO - Replace the coolant pump. See Nuvera® Fuel Cell System Service Manual for procedure.

2.

Check for blockages in the cooling lines. Are cooling lines blocked?

YES - Remove the blockage or replace the cooling line. See Nuvera® Fuel Cell System Service Manual for procedure.

NO - Proceed to Step 3.

3.

Check the level of coolant in the radiator. Is coolant low?

YES - Add coolant. See Nuvera® Fuel Cell System Service Manual for procedure.

NO - Proceed to Step 4.

4.

If DTC 516152 still triggers, contact HYG for assistance.

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Diagnostic troubleshooting codes

DTC 516152 (FMI 18) (0x7E038)-FCS Stack Coolant pressure low Tripping conditions FMI 18: Coolant pressure differential between stack inlet and outlet is below the minimum threshold based on pump speed for 5 seconds Action Warning Activation states Always Reset Clears when differential pressure returns above minimum threshold

Diagnose and troubleshoot DTC 516152 1. Use the Nuvera® Fuel Cell System Serice Tool to confirm the coolant pump is functioning properly?

YES - Proceed to Step 2.

NO - Replace the coolant pump. See Nuvera® Fuel Cell System Service Manual for procedure.

2.

Check for blockages in the cooling lines. Are cooling lines blocked?

YES - Remove the blockage or replace the cooling line. See Nuvera® Fuel Cell System Service Manual for procedure.

NO - Proceed to Step 3.

3.

Check the level of coolant in the radiator. Is coolant low?

YES - Add coolant. See Nuvera® Fuel Cell System Service Manual for procedure.

NO - Proceed to Step 4.

4.

If DTC 516152 still triggers, contact HYG for assistance.

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Diagnostic troubleshooting codes

DTC 516176 (FMI 31) (0x7E050)-Coolant system, pump controller communication error Tripping conditions FMI 31: Coolant pump controller is not responding via CAN. Action Shutdown. Lift lockout is engaged. Battery continues to operate.

Activation states Always Reset Clears after a power cycle

Diagnose and troubleshoot DTC 516176 1. Check for power to the pump controller.

• Measure the voltage between CPPWR.3 and CPPWR.2 of 840-10127-01. The measured voltage should be 20-25Vdc. 2.

Is there power to the pump controller?

YES - Proceed to Step 3.

NO - Proceed to Step 7.

3.

Check if CAN bus is malfunctioning.

• With the system completely powered down, use a multimeter to verify the CAN bus is connected and properly terminated. Measured resistance between CPCOM.1 and CPCOM.6 of P/N 31009953 should be 60Ω +/-10Ω.

• Verify there is no continuity between the CAN wires, CPCOM.1 and CPCOM.6, and the power/ ground wires, CPPWR.3 and CPPWR.2.

4.

Is CAN bus functioning properly?

YES - Proceed to Step 5.

NO - Proceed to Step 7.

5.

Verify continuity of the CAN wires between the Pump Controller and the STW. • Measure continuity from CPCOM.1 (yellow) of P/N 31009954 to STW.7 (yellow) of 31009893.

• Measure continuity from CPCOM.6 (green) of P/N 31009954 to STW.26 (green) of 31009893.

6.

Is there continuity?

YES - Replace the coolant pump. See Nuvera® Fuel Cell System Service Manual for procedure.

NO - Proceed to Step 7.

7.

If DTC 516176 still triggers, contact HYG for assistance.

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Diagnostic troubleshooting codes

DTC 516177 (FMI 4) (0x7E051)-Coolant system, Stack inlet temp. voltage low or shorted to ground Tripping conditions FMI 4: Coolant temperature indicates above 105 °C (instant).

Action Shutdown. Lift lockout is engaged. Battery continues to operate.

Activation states Always Reset Clears after a power cycle

Diagnose and troubleshoot DTC 516177 1. Check for faulty wiring between sensor and controller.

• Verify continuity between LS6.A of P/N 31009954 and ground.

• Verify continuity between LS6.B of P/N 31009954 and the input to the Main PCB on J3.102 circular connector.

• With LS6 of P/N 31009954 unplugged measure the resistance present on the harness between LS6.A and LS6.B. This resistance should be 280 kΩ+/-5kΩ.

2.

Is faulty wiring found?

YES - Proceed to Step 3.

NO - Proceed to Step 5.

3.

Check if sensor is malfunctioning.

• Unplug the sensor and measure the resistance. Resistance should be greater than 1.0kΩ (if hot) and less than 12.5kΩ (if very cold). For reference, the resistance should be approximately 2kΩ – 4.7kΩ at room temperature. If the measured resistance is abnormal compared to these values, it must be replaced.

4.

Is sensor functioning properly?

YES - Proceed to Step 5.

NO - Replace the sensor. See Nuvera® Fuel Cell System Service Manual for procedure.

5.

If DTC 516177 still triggers, contact HYG for assistance.

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Diagnostic troubleshooting codes

DTC 516177 (FMI 3) (0x7E051)-Coolant system, Stack inlet temp. voltage high or shorted to high source Tripping conditions FMI 3: Coolant temperature indicates below -40 °C (instant).

Action Shutdown. Lift lockout is engaged. Battery continues to operate.

Activation states Always Reset Clears after a power cycle

Diagnose and troubleshoot DTC 516177 1. Check for faulty wiring between sensor and controller.

• Verify continuity between LS6.A of P/N 31009954 and ground.

• Verify continuity between LS6.B of P/N 31009954 and the input to the Main PCB on J3.102 circular connector.

• With LS6 of P/N 31009954 unplugged measure the resistance present on the harness between LS6.A and LS6.B. This resistance should be 280 kΩ+/-5kΩ.

2.

Is faulty wiring found?

YES - Proceed to Step 3.

NO - Proceed to Step 5.

3.

Check if sensor is malfunctioning.

• Unplug the sensor and measure the resistance. Resistance should be greater than 1.0kΩ (if hot) and less than 12.5kΩ (if very cold). For reference, the resistance should be approximately 2kΩ – 4.7kΩ at room temperature. If the measured resistance is abnormal compared to these values, it must be replaced.

4.

Is sensor functioning properly?

YES - Proceed to Step 5.

NO - Replace the sensor. See Nuvera® Fuel Cell System Service Manual for procedure.

5.

If DTC 516177 still triggers, contact HYG for assistance.

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Diagnostic troubleshooting codes

DTC 516178 (FMI 4) (0x7E052)-Coolant system, Stack outlet temp. voltage low or shorted to ground Tripping conditions FMI 4: Coolant temperature indicates above 105 °C (instant) Action Shutdown. Lift lockout is engaged. Battery continues to operate.

Activation states Always Reset Clears after a power cycle

Diagnose and troubleshoot DTC 516178 1. Check for faulty wiring between sensor and controller.

• Verify continuity between LS6.A of P/N 31009954 and ground.

• Verify continuity between LS6.B of 31009954 and the input to the Main PCB on J3.102 circular connector.

• With LS4 of 31009954 unplugged measure the resistance present on the harness between LS6.A and LS6.B. This resistance should be 280 kΩ+/-5kΩ.

2.

Is faulty wiring found?

YES - Proceed to Step 3.

NO - Proceed to Step 5.

3.

Check if sensor is malfunctioning.

• Unplug the sensor and measure the resistance. Resistance should be greater than 1.0kΩ (if hot) and less than 12.5kΩ (if very cold). For reference, the resistance should be approximately 2kΩ – 4.7kΩ at room temperature. If the measured resistance is abnormal compared to these values, it must be replaced.

4.

Is sensor functioning properly?

YES - Proceed to Step 5.

NO - Replace the sensor. See Nuvera® Fuel Cell System Service Manual for procedure.

5.

If DTC 516178 still triggers, contact HYG for assistance.

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Diagnostic troubleshooting codes

DTC 516178 (FMI 3) (0x7E052)-Coolant system, Stack outlet temp. voltage high or shorted to high source Tripping conditions FMI 3: Coolant temperature indicates below -40 °C (instant).

Action Shutdown. Lift lockout is engaged. Battery continues to operate.

Activation states Always Reset Clears after a power cycle Tripping conditions Voltage above normal or shorted to high source FMI 3: Coolant temperature indicates below -40 °C (instant).

Reaction Shutdown. Lift lockout is engaged. Battery continues to operate.

Reset Clears after a power cycle

Diagnose and troubleshoot DTC 516178 1. Check for faulty wiring between sensor and controller.

• Verify continuity between LS6.A of P/N 31009954 and ground.

• Verify continuity between LS6.B of 31009954 and the input to the Main PCB on J3.102circular connector.

• With LS6 of P/N 31009954 unplugged measure the resistance present on the harness between LS6.A and LS6.B. This resistance should be 280 kΩ+/-5kΩ.

2.

Is faulty wiring found?

YES - Proceed to Step 3.

NO - Proceed to Step 5.

3.

Check if sensor is malfunctioning.

• Unplug the sensor and measure the resistance. Resistance should be greater than 1.0kΩ (if hot) and less than 12.5kΩ (if very cold). For reference, the resistance should be approximately 2kΩ – 4.7kΩ at room temperature. If the measured resistance is abnormal compared to these values, it must be replaced.

4.

Is sensor functioning properly?

YES - Proceed to Step 5.

NO - Replace the sensor. See Nuvera® Fuel Cell System Service Manual for procedure.

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Diagnostic troubleshooting codes

DTC 516178 (FMI 3) (0x7E052)-Coolant system, Stack outlet temp. voltage high or shorted to high source (continued) Diagnose and troubleshoot DTC 516178 (continued) 5.

If DTC 516178 still triggers, contact HYG for assistance.

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Diagnostic troubleshooting codes

DTC 516192 (FMI 31) (0x7E060)-Cathode system, compressor controller communication error Tripping conditions FMI 31: Condition –Cathode Compressor controller is not responding via CAN. Action Shutdown. Lift lockout is engaged. Battery continues to operate until Battery, SOC (0x7E011h) DTC is trigged.

Activation states Always Reset Clears after a power cycle

Diagnose and troubleshoot DTC 516192 1. Check for power to the motor controller.

• Check continuity between QCCPVMOT1 of P/N 31009953 and the battery contactor output terminal. If open circuit, check the inline fuse supplying the motor controller. See Figure 7.

• Check continuity between QCCPGND of P/N 31009953 and the chassis ground. See Figure 7.

Figure 7. Fuse holders 1.

30A FUSE HOLDER

2.

2.

Is there power to the motor controller?

40A FUSE HOLDER

YES - Proceed to Step 3.

NO - Proceed to Step 7.

3.

Check if CAN bus is malfunctioning.

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DTC 516192 (FMI 31) (0x7E060)-Cathode system, compressor controller communication error (continued) Diagnose and troubleshoot DTC 516192 (continued) • With the system completely powered down, use a multimeter to verify the CAN bus is connected and properly terminated. Measured resistance between DCDC.3 and DCDC.4 of DC Harness (31009894) should be 60 Ω.

• Verify there is no continuity between the CAN wires, DCDC.3 and DCDC.4, and the power/ ground wires, DCDC.5 and DCDC.6.

4.

Is CAN bus functioning properly?

YES - Proceed to Step 5.

NO - Proceed to Step 7.

5.

Verify continuity of the CAN wires between the DCDC and the STW • Measure continuity from DCDC.4 (yellow) of P/N 31009894 to STW.7 (yellow) of P/N 31009893.

• Measure continuity from DCDC.3 (green) of P/N 31009894 to STW.26 (green) of P/N 31009893.

6.

Is there continuity?

YES - Replace the motor controller. See Nuvera® Fuel Cell System Service Manual for procedure.

NO - Proceed to Step 7.

7.

If DTC 516192 still triggers, contact HYG for assistance.

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Diagnostic troubleshooting codes

DTC 516193 (FMI 31) (0x7E061)-Cathode system, flow measurement error Tripping conditions FMI 1: Below normal operating range-most severe.

Action Shutdown. Lift lockout is engaged. Battery continues to operate until Battery, SOC (DTC 516113) is triggered.

Activation states Always Reset Clears after a power cycle

Diagnose and troubleshoot DTC 516193 1. Check wiring between Mass Air Flow (MAF) sensor and controller.

• (Sensor Feedback) Verify continuity between STW.74 of P/N 31009893 to MAF.3 of P/N 31009952.

• (Sensor Ground) Verify continuity between MAF.2 of P/N 31009952 and 12V SLA negative terminal.

• (Sensor Power) Verify continuity between MAF.1 of P/N 31009952 and DCDC.5 of P/N 31009894.

2.

Is wiring faulty?

YES - Proceed to Step 3.

NO - Proceed to Step 7.

3.

Check if MAF sensor is malfunctioning.

• With MAF powered, MAF.3 should read between 0.5V and 4.5V. If voltage feedback is good and fault is still occurring, replace sensor.

4.

Is MAF sensor functioning properly?

YES - Proceed to Step 5.

NO - Replace MAF sensor. See Nuvera® Fuel Cell System Service Manual for procedure.

5.

Verify compressor is functioning properly.

• Verify compressor turns at startup by listening for compressor sound.

• To confirm compressor operation, verify pressure build-up at startup using PCST monitor CS2 or CS3 pressure build up above ambient (98kPa).

• If compressor is not turning at startup, verify wiring is properly seated on Motor Controller above the main battery. See Figure 8.

• Verify compressor connector is fully seated and pin/sockets are seated properly. See Figure 9.

• Remove the battery by following the steps in Nuvera® Fuel Cell System Service Manual.

• Inspect the connector using an inspection mirror if necessary.

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DTC 516193 (FMI 31) (0x7E061)-Cathode system, flow measurement error (continued) Diagnose and troubleshoot DTC 516193 (continued) 6.

Is compressor functioning properly?

YES - Proceed to Step 7.

NO - Replace the compressor. See Nuvera® Fuel Cell System Service Manual for procedure.

7.

If DTC 516193 still triggers, contact HYG for assistance.

Figure 8. Motor controller and main battery 1.

MOTOR WIRING

2.

CONTROLLER WIRING

Figure 9. Compressor connector

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Diagnostic troubleshooting codes

DTC 516097 (FMI 31) (0x7E001)-Distributed IO, Communication error Tripping conditions FMI 31: Distributed IO (DIO) module is not responding via CAN Action Fuel cell charging system is shutdown. Limited Operationis engaged. Battery continues to operate.

Activation states Always Reset Clears after a power cycle

Diagnose and troubleshoot DTC 516097 1. Check if the DIO is powered on. Are three LED's located on the Main PCB on?

YES - Proceed to Step 3.

NO - Proceed to Step 2.

2.

Check if the relay providing power to DIO is functioning properly.

• Measure for 12Vs on main PCB. Volts should be 12-14V. • Measure for voltage at the SLA battery. Volts should be 13-14V.

3.

Check if the CANbus is functioning properly.

• With the system completely powered down, use a multimeter to verify the CAN 1 bus is connected and properly terminated. Measured resistance between C1.2 and C1.3 of the 12-pin DTM connector on the User Connector harness (P/N 310009896) should be 60 Ω. Verify there is no continuity from the CAN wires, C1.2 and C1.3, to the power/ground wires, C1.12 and C1.1.

• Verify continuity of the CAN wires between the Distributed IO module and the STW. Measure continuity from C1.1 (yellow) of User Connector harness (P/N 310009896) to STW.7 (yellow) of the 81-pin STW connector on harness STW harness (P/N 310009893). Measure continuity from C1.2 (green) of User Connector harness (P/N 310009896) to STW.26 (green) of the 81-pin STW connector on STW harness (P/N 310009893).

4.

Inspect main PCB for evidence of damage to circuits or components. Is damage found?

YES - Remove and replace the Main PCB and return to manufacturer. See Nuvera® Fuel Cell System Service Manual.

NO - Proceed to Step 5.

5.

If DTC 516097 still triggers, contact HYG for assistance.

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Diagnostic troubleshooting codes

DTC 516098 (FMI 0) (0x7E002) or 516100 (FMI 0) (0x7E004)-LFL critically high Tripping conditions FMI 0: Hydrogen content in air is above 2.0 % (2.5% actual) Action Immediate shutdown of the H2 System. System faults (SWS active) and shuts all systems down within 30 seconds.

Activation states Always Reset Clears after a power cycle

Diagnose and troubleshoot DTC 516098 or DTC 516100 1. Check if hydrogen is being properly supplied to the FCS stack. Perform a leak check and inspect all plumbing for leaks. See Nuvera® Fuel Cell System Service Manual for procedure.

Was a leak detected?

YES - Identify the location of the leak. Repair or replace hydrogen plumbing as needed. See Nuvera® Fuel Cell System Service Manual.

NO - Proceed to Step 2.

2.

Wiring between the output sensor and controller may be faulty.

• Verify the sensor has power. Probe between AS6.4 and AS6.1 (GND) of P/N 31009954. The measured voltage should be 12V. • Verify continuity between AS6.1 and ground. Use the 12V SLA negative terminal (black) as a ground reference.

• Verify continuity of the CAN wires between the AS6 and the STW. Measure continuity from AS6.2 (yellow) of 31009954 to STW.7 (yellow) of STW harness (P/N 31009893). Measure continuity from AS6.3 (green) of 31009954 to STW.26 (green) of 31009893.

3.

Check if output sensor is functioning properly (AS5 sensor for 516098, AS6 sensor for 516100).

• Verify sensor is communicating to the CAN networkusing PCST or a CAN Adapter and appropriate .dbc file.

• If the hydrogen leak sensor is not accurate or no leaks are found, replace hydrogen leak sensor.

4.

Is the output sensor functioning properly?

YES - Proceed to Step 5.

NO - Remove and replace the sensor. See Nuvera® Fuel Cell System Service Manual for procedure.

Restart FCS and wait for startup.

5.

If DTC 516098 or 516100 still trigger, contact HYG for assistance.

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Diagnostic troubleshooting codes

DTC 516098 (FMI 16) (0x7E002) or 516100 (FMI 16) (0x7E004)-LFL high Tripping conditions FMI 16: Hydrogen content in air is > 1.5 % (2.0% actual) Action Immediate shutdown of the H2 sub-system. Fans operate at 50% speed. Limited Operation mode is activated.

Activation states Always Reset Clears after a power cycle

Diagnose and troubleshoot DTC 516098 (Sensor 1) or 516100 (Sensor 2) 1. Check if hydrogen is being properly supplied to the FCS stack. Perform a leak check and inspect all plumbing for leaks. See Nuvera® Fuel Cell System Service Manual for procedure.

Was a leak detected?

YES - Identify the location of the leak. Repair or replace hydrogen plumbing as needed. See Nuvera® Fuel Cell System Service Manual.

NO - Proceed to Step 2.

2.

Wiring between the output sensor and controller may be faulty.

• Verify the sensor has power. Probe between AS6.4 and AS6.1 (GND) of P/N 31009954. The measured voltage should be 12V. • Verify continuity between AS6.1 and ground. Use the 12V SLA negative terminal (black) as a ground reference.

• Verify continuity of the CAN wires between the AS6 and the STW. Measure continuity from AS6.2 (yellow) of 31009954 to STW.7 (yellow) of STW harness (P/N 31009893). Measure continuity from AS6.3 (green) of 31009954 to STW.26 (green) of 31009893.

3.

Check if output sensor is functioning properly (AS5 sensor for 516098, AS6 sensor for 516100).

• Verify sensor is communicating to the CAN networkusing PCST or a CAN Adapter and appropriate .dbc file.

• If the hydrogen leak sensor is not accurate or no leaks are found, replace hydrogen leak sensor.

4.

Is the output sensor functioning properly?

YES - Proceed to Step 5.

NO - Remove and replace the sensor. See Nuvera® Fuel Cell System Service Manual for procedure.

Restart FCS and wait for startup.

5.

If DTC 516098 or 516100 still trigger, contact HYG for assistance.

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Diagnostic troubleshooting codes

DTC 516098 (FMI 15) (0x7E002) or 516100 (FMI 15) (0x7E004)-LFL above normal range Tripping conditions FMI 15: Hydrogen content in air is above 1.0 % Action Warning Activation states Clears when hydrogen content is below threshold

Diagnose and troubleshoot DTC 516098 (Sensor 1) or 516100 (Sensor 2) 1. Check if hydrogen is being properly supplied to the FCS stack. Perform a leak check and inspect all plumbing for leaks. See Nuvera® Fuel Cell System Service Manual for procedure.

Was a leak detected?

YES - Identify the location of the leak. Repair or replace hydrogen plumbing as needed. See Nuvera® Fuel Cell System Service Manual.

NO - Proceed to Step 2.

2.

Wiring between the output sensor and controller may be faulty.

• Verify the sensor has power. Probe between AS6.4 and AS6.1 (GND) of 840-10128-01. The measured voltage should be 12V. • Verify continuity between AS6.1 and ground. Use the 12 V SLA negative terminal (black) as a ground reference.

• Verify continuity of the CAN wires between the AS6 and the STW. Measure continuity from AS6.2 (yellow) of 840-10128-01 to STW.7 (yellow) of 840-10131-01. Measure continuity from AS6.3 (green) of 840-10128-01 to STW.26 (green) of 840-10131-01

3.

Check if output sensor is functioning properly (AS5 sensor for 516098, AS6 sensor for 516100).

• Verify sensor is communicating to the CAN networkusing PCST or a CAN Adapter and appropriate .dbc file.

• If the hydrogen leak sensor is not accurate or no leaks are found, replace hydrogen leak sensor.

4.

Is the output sensor functioning properly?

YES - Proceed to Step 5.

NO - Remove and replace the sensor. See Nuvera® Fuel Cell System Service Manual for procedure.

Restart FCS and wait for startup.

5.

If DTC 516098 or 516100 still trigger, contact HYG for assistance.

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Diagnostic troubleshooting codes

DTC 516098 (FHI 3) (0x7E002) or 516100 (FHI 3) (0x7E004)-LFL high or shorted to high source Tripping conditions FMI 3: LFL sensor signal is above 4.875 V Action Immediate shutdown of the H2 sub-system. Lift Lockout is engaged. Battery continues to operate Activation states Always Reset Resets after a power cycle

Diagnose and troubleshoot DTC 516098 (Sensor 1) or 516100 (Sensor 2) 1. Check if hydrogen is being properly supplied to the FCS stack. Perform a leak check and inspect all plumbing for leaks. See Nuvera® Fuel Cell System Service Manual for procedure.

Was a leak detected?

YES - Identify the location of the leak. Repair or replace hydrogen plumbing as needed. See Nuvera® Fuel Cell System Service Manual.

NO - Proceed to Step 2.

2.

Wiring between the output sensor and controller may be faulty.

• Verify the sensor has power. Probe between AS6.4 and AS6.1 (GND) of P/N 31009954. The measured voltage should be 12V. • Verify continuity between AS6.1 and ground. Use the 12 V SLA negative terminal (black) as a ground reference.

• Verify continuity of the CAN wires between the AS6 and the STW. Measure continuity from AS6.2 (yellow) of P/N 31009954 to STW.7 (yellow) of STW harness P/N 31009893. Measure continuity from AS6.3 (green) of P/N 31009954 to STW.26 (green) of P/N 31009893.

3.

Check if output sensor is functioning properly (AS5 sensor for 516098, AS6 sensor for 516100).

• Verify sensor is communicating to the CAN networkusing PCST or a CAN Adapter and appropriate .dbc file.

• If the hydrogen leak sensor is not accurate or no leaks are found, replace hydrogen leak sensor.

4.

Is the output sensor functioning properly?

YES - Proceed to Step 5.

NO - Remove and replace the sensor. See Nuvera® Fuel Cell System Service Manual for procedure.

Restart FCS and wait for startup.

5.

If DTC 516098 or 516100 still trigger, contact HYG for assistance.

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Diagnostic troubleshooting codes

DTC 516098 (FMI 4) (0x7E002) or 516100 (FMI 4) (0x7E004)-LFL low or shorted to low source Tripping conditions FMI 4: LFL sensor signal is below 0.4 V. Action Immediate shutdown of the H2 sub-system. Lift Lockout is engaged.

Activation states Always Reset Resets after power cycle

Diagnose and troubleshoot DTC 516098 (Sensor 1) or 516100 (Sensor 2) 1. Check if hydrogen is being properly supplied to the FCS stack. Perform a leak check and inspect all plumbing for leaks. See Nuvera® Fuel Cell System Service Manual for procedure.

Was a leak detected?

YES - Identify the location of the leak. Repair or replace hydrogen plumbing as needed. See Nuvera® Fuel Cell System Service Manual.

NO - Proceed to Step 2.

2.

Wiring between the output sensor and controller may be faulty.

• Verify the sensor has power. Probe between AS6.4 and AS6.1 (GND) of P/N 31009954. The measured voltage should be 12V. • Verify continuity between AS6.1 and ground. Use the 12 V SLA negative terminal (black) as a ground reference.

• Verify continuity of the CAN wires between the AS6 and the STW. Measure continuity from AS6.2 (yellow) of P/N 31009954 to STW.7 (yellow) of STW harness (P/N 31009893). Measure continuity from AS6.3 (green) of 31009954 to STW.26 (green) of 31009893.

3.

Check if output sensor is functioning properly (AS5 sensor for 516098, AS6 sensor for 516100).

• Verify sensor is communicating to the CAN networkusing PCST or a CAN Adapter and appropriate .dbc file.

• If the hydrogen leak sensor is not accurate or no leaks are found, replace hydrogen leak sensor.

4.

Is the output sensor functioning properly?

YES - Proceed to Step 5.

NO - Remove and replace the sensor. See Nuvera® Fuel Cell System Service Manual for procedure.

Restart FCS and wait for startup.

5.

If DTC 516098 or 516100 still trigger, contact HYG for assistance.

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Diagnostic troubleshooting codes

DTC 516098 (FMI 12) (0x7E002) or 516100 (FMI 12) (0x7E004)-LFL Bad intelligent device or component Tripping conditions FMI 12: LFL sensor CAN communication data indicates a failure.

Action Immediate shutdown of the H2 System. System faults (SWS active) and shuts all systems down within 30 seconds.

Activation states Always Reset Resets after a power cycle. If error condition persists, sensor must be replaced.

Diagnose and troubleshoot DTC 516098 (Sensor 1) or 516100 (Sensor 2) 1. Check if hydrogen is being properly supplied to the FCS stack. Perform a leak check and inspect all plumbing for leaks. See Nuvera® Fuel Cell System Service Manual for procedure.

Was a leak detected?

YES - Identify the location of the leak. Repair or replace hydrogen plumbing as needed. See Nuvera® Fuel Cell System Service Manual.

NO - Proceed to Step 2.

2.

Wiring between the output sensor and controller may be faulty.

• Verify the sensor has power. Probe between AS6.4 and AS6.1 (GND) of P/N 31009954. The measured voltage should be 12V. • Verify continuity between AS6.1 and ground. Use the 12V SLA negative terminal (black) as a ground reference.

• Verify continuity of the CAN wires between the AS6 and the STW. Measure continuity from AS6.2 (yellow) of 31009954 to STW.7 (yellow) of STW harness P/N 31009893. Measure continuity from AS6.3 (green) of 31009954 to STW.26 (green) of 31009893.

3.

Check if output sensor is functioning properly (AS5 sensor for 516098, AS6 sensor for 516100).

• Verify sensor is communicating to the CAN networkusing PCST or a CAN Adapter and appropriate .dbc file.

• If the hydrogen leak sensor is not accurate or no leaks are found, replace hydrogen leak sensor.

4.

Is the output sensor functioning properly?

YES - Proceed to Step 5.

NO - Remove and replace the sensor. See Nuvera® Fuel Cell System Service Manual for procedure.

Restart FCS and wait for startup.

5.

If DTC 516098 or 516100 still trigger, contact HYG for assistance.

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Diagnostic troubleshooting codes

DTC 516098 (FMI 14) (0x7E002) or 516100 (FMI 14) (0x7E004)-Special instructions Tripping conditions FMI 14: Condition –LFL Sensor Signal is 0.5V (0.4 – 0.75V) Action Fuel cell charging system is shutdown. Lift lockout is engaged. Battery continues to operate.

Activation states Always Reset Resets after a power cycle. If error condition persists, sensor must be replaced.

Diagnose and troubleshoot DTC 516098 (Sensor 1) or 516100 (Sensor 2) 1. Check if hydrogen is being properly supplied to the FCS stack. Perform a leak check and inspect all plumbing for leaks. See Nuvera® Fuel Cell System Service Manual for procedure.

Was a leak detected?

YES - Identify the location of the leak. Repair or replace hydrogen plumbing as needed. See Nuvera® Fuel Cell System Service Manual.

NO - Proceed to Step 2.

2.

Wiring between the output sensor and controller may be faulty.

• Verify the sensor has power. Probe between AS6.4 and AS6.1 (GND) of 840-10128-01. The measured voltage should be 12V. • Verify continuity between AS6.1 and ground. Use the 12 V SLA negative terminal (black) as a ground reference.

• Verify continuity of the CAN wires between the AS6 and the STW. Measure continuity from AS6.2 (yellow) of P/N 31009954 to STW.7 (yellow) of STW harness (P/N 31009893). Measure continuity from AS6.3 (green) of 31009954 to STW.26 (green) of P/N 31009893.

3.

Check if output sensor is functioning properly (AS5 sensor for 516098, AS6 sensor for 516100).

• Verify sensor is communicating to the CAN networkusing PCST or a CAN Adapter and appropriate .dbc file.

• If the hydrogen leak sensor is not accurate or no leaks are found, replace hydrogen leak sensor.

4.

Is the output sensor functioning properly?

YES - Proceed to Step 5.

NO - Remove and replace the sensor. See Nuvera® Fuel Cell System Service Manual for procedure.

Restart FCS and wait for startup.

5.

If DTC 516098 or 516100 still trigger, contact HYG for assistance.

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Diagnostic troubleshooting codes

DTC 516096 (FMI 31) (0x7E000)-E-stop active Tripping conditions FMI 31: E-stop is pressed.

Action System faults and immediately shuts down all systems except datalogger. System turns off after 5 minutes or within 2 seconds of E-Stop reset.

Activation states Always Reset Clears after a power cycle

Diagnose and troubleshoot DTC 516096 1. Is the E-stop switch pressed?

YES - Reset the E-stop and restart the FCS. NO - Proceed to Step 2.

2.

Check if the E-stop switch is malfunctioning.

• When the E-stop is in the running (out) position, verify continuity between HYSTER.9 and HYSTER.10 of communication harness on Main PCB. Push the E-stop and repeat continuity test.

When the E-stop is pressed, there should be no continuity. See Figure 10.

• Confirm E-Stop backshell (EAO 61-8775.11) is fully seated onto E-Stop switch and in the correct orientation.

• E-stop button should release easily if the backshell is in the correct orientation.

• Confirm wires are seated into correct pins on E-Stop backshell (EAO 61-8775.11) (pins 21 and 22) and screw terminals are tight.

3.

Is E-stop functioning properly?

YES - Proceed to Step 4.

NO - Replace the E-stop switch. See Nuvera® Fuel Cell System Service Manual for procedure.

4.

If DTC 516096 still triggers, contact HYG for assistance.

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Diagnostic troubleshooting codes

DTC 516096 (FMI 31) (0x7E000)-E-stop active (continued) Diagnose and troubleshoot DTC 516096 (continued)

Figure 10. E-stop backshell

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Diagnostic troubleshooting codes

DTC 516099 (FMI 31)-SWS Loop Fault Tripping conditions FMI 31: E-stop is pressed.

Action System faults at start up Activation states Always

Diagnose and troubleshoot DTC 516099 1. Is the E-stop switch pressed?

YES - Reset the E-stop and restart the FCS. NO - Proceed to Step 2.

2.

Is the integration harness connected properly?

YES - Proceed to Step 3.

NO - Connect the integration harness. Return FCS to service.

3.

If DTC 516099 is still triggering: • Disconnect 12 pin connector of the interface harness and check for continuity between pins 9 and 10 on the truck side.

• Connect 12 pin connector to the FCS and check for 12V between pins 9 and 12 (pin 9 positive).

4.

Is 12V found between pins 9 and 12?

YES - Proceed to Step 6.

NO - Proceed to Step 5.

5.

Check fuse 20. If fuse is blown, replace with new.

6.

If DTC 516099 still triggers, contact HYG for assistance.

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Observed symptoms

FCS will not turn on

Observed issue: • The FCS is quiet and has no external lights (start button and HMI are not on).

• The FCS does not respond when pressing the start button.

• After pressing START button the green LED on the button flashes for 1-2 seconds then turns off.

Possible cause The 12 V battery may be too discharged for the FCS to start.

NOTE: This is a 5A fused connection directly to the 12V SLA battery. If this pin is shorted to ground, it can open the fuse and the fuse will need to be replaced after correcting the shorting condition.

1.

Verify voltage between pin 12 of the 12-pin USER connector (12Vc) and pin 1 of the 12-pin USER connector (ground)is above 11.5V.

The voltage is lower than 11V and the battery must be replaced.

1.

Remove the battery and replace. See Nuvera® Fuel Cell System Service Manual for procedure.

2.

If a battery is not available, the system can be “jump started” by applying 12V to the user connection (User.12 = 12V, User.1 = GND) until the system is started. DO NOT apply more than 15V to the User pins. DO NOT connect the pins in reverse polarity. After starting, the system will maintain 12V until it shuts down.

Observed issue: • After pressing the START button, the green LED flashes for exactly 5 seconds, then turns off.

Possible cause The E-stop button may be depressed.

• Confirm the E-stop is in the released position. If the E-stop is pushed all the way in, twist and release the E-stop to release.

Possible cause The 6-pin connection to the truck may not be plugged in or properly wired.

1.

Confirm the the connector from the FCS harness to the truck harness is plugged in and all wires as are functioning properly.

2.

Connect the E-stop connector the FCS harness.

3.

Confirm proper wiring on both sides of the 6-pin connector.

1.

N/C

2.

E-stop (red)

3.

CAN_HI (yellow)

4.

CAN_LO (green)

5.

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Observed symptoms

FCS will not turn on (continued) Observed issue: (continued) Possible cause (continued) 6. Chassis bonding (black) Possible cause Fuse 20 is open.

1.

Check fuse 20. Replace with new if blown.

FCS On, No DTC-No voltage from the main contactor

Observed issue: • The FCS is on and the solid green LED is on the START button, but there is no power to the truck.

Possible cause The output power connector may be damaged.

• Visually inspect for heat or corrosion on the connector housing or terminals.

• Replace the output connector or connector/cable combo.

Possible cause The output power cable may be damaged, loose or disconnected.

• Locate the contactor/output cable area.

• Inspect output cables for loose connections or heat evidence marks.

Solution • If cables have burned or overheated, they should be replace or repaired. To remove and replace the cables, see Nuvera® Fuel Cell System Service Manual.

• Cables can be reused if shortening is an option. Cutting approximately 200mm from the hot end should be sufficient to remove the heat damage.

1.

Torque contactor nuts to 10 Nm (90 in lbs).

2.

Torque pass through bolts to 6.5 Nm (60 in lbs).

3.

Torque battery terminals to 12 Nm (110 in lbs).

Possible cause The output connector is not operating properly.

Solution 1. Disconnect the system from application.

2.

Start the system.

3.

Listen for three audible clicks from the contactors.

4.

Use a multimeter to measure voltage from the main ground terminals to the output cable contactor stud. a.

If voltage is present, inspect cable connections and crimps. Look for heat witness marks.

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Observed symptoms

FCS On, No DTC-No voltage from the main contactor (continued) Observed issue: (continued) Solution (continued) b. Replace cables if damaged. c.

5.

Tighten contactor terminals to 10 Nm (90 in lbs) if loose.

Disconnect output contactor connector – measure pins for 12Vdc. Should see 12V while system is in “Run” mode. a.

If no voltage is present, inspect wiring to main PCB.

b.

Check crimps on connector to main PCB.

c.

Check Main PCB connector pins. Verify pins are not bent or missing. Contact manufacturer for problems with crimped wires or PCB damage.

Observed issue: • The FCS is on and the solid green LED is on the START button, but there is no power to the truck.

Possible cause The output power connector may be damaged.

• Visually inspect for heat or corrosion on the connector housing or terminals.

• Replace the output connector or connector/cable combo.

Possible cause The output power cable may be damaged, loose or disconnected.

• Locate the contactor/output cable area.

• Inspect output cables for loose connections or heat evidence marks.

Solution • If cables have burned or overheated, they should be replace or repaired. To remove and replace the cables, see Nuvera® Fuel Cell System Service Manual.

• Cables can be reused if shortening is an option. Cutting approximately 200mm from the hot end should be sufficient to remove the heat damage.

1.

Torque contactor nuts to 10 Nm (90 in lbs).

2.

Torque pass through bolts to 6.5 Nm (60 in lbs).

3.

Torque battery terminals to 12 Nm (110 in lbs).

Possible cause The output connector is not operating properly.

Solution 1. Disconnect the system from application.

2.

Start the system.

3.

Listen for three audible clicks from the contactors.

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Observed symptoms

FCS On, No DTC-No voltage from the main contactor (continued) Observed issue: (continued) Solution (continued) 4. Use a multimeter to measure voltage from the main ground terminals to the output cable contactor stud.

5.

a.

If voltage is present, inspect cable connections and crimps. Look for heat witness marks.

b.

Replace cables if damaged.

c.

Tighten contactor terminals to 10 Nm (90 in lbs) if loose.

Disconnect output contactor connector – measure pins for 12Vdc. Should see 12V while system is in “Run” mode. a.

If no voltage is present, inspect wiring to main PCB.

b.

Check crimps on connector to main PCB.

c.

Check Main PCB connector pins. Verify pins are not bent or missing. Contact manufacturer for problems with crimped wires or PCB damage.

Possible cause Truck fuse is blown.

Solution 1. Shut down system.

2.

Remove top panel.

3.

Identify large white 450A fuse (underneath the main harnesses leaving the electrical box) and confirm continuity across the ends with a multimeter. a.

If continuity is not found, relace fuse.

FCS is on, Fuel gauge does not function properly

Observed issue:

Fuel gauge does not show any lights or make any noise. System appears to function normally. Solid green LED on START button.

Possible cause HMI is not connected.

1.

Verify the connector is seated properly.

2.

Fully screw the collar onto the M8 connector on the FCS.

3.

The connection should only need to behand-tightened. If a tool seems to be required, inspect FCS connection for debris.

HMI is damaged/not functioning properly.

1.

Remove the HMI from the fuel cell system (this can be done without shutting the system off).

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Observed symptoms

FCS is on, Fuel gauge does not function properly (continued) Observed issue: (continued) Possible cause (continued) 2. Inspect the HMI pins. Should see 4 straight gold-plated pins inside the M8 connector.

Replace if damaged.

3.

Inspect yellow cable. Ensure no cuts are visible on the outer covering. Replace if damaged.

4.

Connect the HMI to another FCS, and check if it's functioning.

5.

Connect a different HMI to your FCS and check if the HMI turns on.

6.

If the different HMI functions properly, send the faulty HMI to the manufacturer for repair.

The HMI connector on the FCS is damaged or jammed with debris.

1.

Disconnect the connector on the HMI from the connector on the FCS harness.

2.

Inspect the FCS connector and take photographs to document. Contact HYG for assistance.

The HMI is not powered.

1.

Verify 12V power is available at the 12-wire HMI connector on the Main PCB.

2.

Replace the HMI. See Nuvera® Fuel Cell System Service Manual for procedure. Send the faulty HMI to the manufacturer for repair.

Figure 11. HMI connector

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Observed symptoms

FCS is on, Fuel gauge does not function properly (continued)

Observed issue:

Fual gauge on the HMI does not make noise.

After pressing the START button, the green LED flashes for exactly 5 seconds, then turns off.

Possible cause The HMI speaker may be damaged.

• Remove the HMI and replace with new. See Nuvera® Fuel Cell System Service Manual for procedure.

• Return the HMI to the manufacturer for repair.

Observed issue: HMI flashes with an orange color on all LEDs, then turns off. FCS remains on and functional.

Possible cause An HMI data line is disconnected or broken.

1.

Turn the FCS off.

2.

Open the top panel.

3.

Inspect the wiring at the rear of the M8 connector. If the wiring is disconnected or shorted, replace the wire harness. See Nuvera® Fuel Cell System Service Manual for procedure.

4.

Inspect wiring at the main PCB HMI connector for broken or loose terminals.

5.

Inspect main PCB HMI connector for bent or broken pins.

6.

a.

If bent, carefully straighten the pins.

b.

If a pin is broken, remove and replace the main PCB. See Nuvera® Fuel Cell System Service Manual for procedure. Return the faulty main PCB to the manufacturer for repair. When installing the new main PCB, make sure to use the same SD card as the faulty PCB.

Confirm the HMI is now functioning.

Observed issue: Fuel gauge does not work. System does not output voltage/power.

See FCS will not turn on and follow procedures.

FCS does not transmit data

Observed issue:

The data logger is not booting properly.

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Observed symptoms

FCS does not transmit data (continued) Observed issue: (continued) Possible cause SD card is not fully seated.

1.

Fully seat the SD card on the Main PCB.

SD card is corrupted.

1.

Replace the SD card. Contact HYG for assistance.

Observed issue: The datalogger does not have a working cellular modem.

Possible cause Modem is not powered.

1.

Verify green LED on the modem PCB when the system is powered on.

2.

If no green LED is visible on the modem: 1.

Inspect the USB wiring to the modem.

• Verify 5V is present when the system has 12V's of power (use pin 4 ground for 5V reference measurement).

• Verify the integrity of USB_N (Wh) and USB_P (Gr) wires using a multimeter. Do not insert anything inside the sockets of the wiring harness pins. It can enlarge and deform the sockets and make future intermittent connections.

2.

Inspect 5V power from the main PCB.

• Measure for 5V on main PCB connector.

Possible cause Modem is damaged NOTE: In some cases, the SIM card is linked to the modem. Because of this, the SIM card should not be removed without a call to the manufacturer to verify service. If the SIM is changed, the IMEI of the modem and the SIM card number will both be required when calling for assistance.

1.

Replace the modem. Contact HYG for assistance.

Observed issue: The datalogger is not connected to the CANbus.

Possible cause The wiring is damaged or faulty.

1.

Inspect the USB wiring to the modem.

• Verify 5V is present when the system has 12V's of power (use pin 4 ground for 5V reference measurement).

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Observed symptoms

FCS does not transmit data (continued) Observed issue: (continued) Possible cause (continued) • Verify the integrity of USB_N (Wh) and USB_P (Gr) wires using a multimeter. Do not insert anything inside the sockets of the wiring harness pins. It can enlarge and deform the sockets and make future intermittent connections.

Observed issue: The datalogger processor is not functioning properly.

Possible cause Datalogger processor board is dislodged.

• Inspect datalogger CM3 board on Main PCB. • Re-seat the datalogger processor board, only if it is visibly disconnected.

NOTE: This should not be reseated unless it is visibly disconnected or there’s obviously something wrong Possible cause Datalogger processor board is damaged.

• Replace board using standard laptop DIMM replacement procedure.

• New CM3+/LITE modules are available from the manufacturer or on the open market.

Possible cause Datalogger processor board is not powered.

• Verify 12V switched power is active.

• Verify 5A battery fuse (brown) is not open circuit.

Excessive noise

Observed issue: Rapid and regular ticking, clicking or buzzing.

Possible cause FCS may have something touching the main DCDC fan blades.

1.

Turn the FCS off. Engage the E-stop.

2.

Use a work light to identify any potential interference with the fan blades.

• If an obstruction is found, remove the side panel, clear the obstruction and return the side panel to its position.

3.

Inspect the DCDC fan for obstruction.

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Observed symptoms

Excessive noise (continued) Observed issue: (continued) Possible cause (continued) NOTE: The DCDC fan is supposed to run continuously at a low speed and increase as the DCDC temperature rises. An intermittent fan or one that is not blowing a slight amount of air could indicate a blockage or stalled fan. This should be addressed immediately.

FCS may have something touching the radiator fan blades.

1.

Turn the FCS off. Engage the E-stop.

2.

Use a work light to identify any potential interference with the radiator fan blades.

• If an obstruction is found, remove the side panel, clear the obstruction and return the side panel to its position.

3.

Inspect the radiator fan for obstruction.

FCS may have something obstructing the battery fan blades.

1.

Turn the FCS off. Engage the E-stop.

2.

Use a work light to identify any potential interference with the fan blades.

• If an obstruction is found, remove the side panel, clear the obstruction and return the side panel to its position.

FCS may have something touching the compressor fan blades.

1.

Turn the FCS off. Engage the E-stop.

2.

Use a work light to identify any potential interference with the compressor fan blades.

• If an obstruction is found, remove the side panel, clear the obstruction and return the side panel to its position.

Unit may have an intermittent connection on a contactor.

1.

Remove the top cover.

2.

Measure the voltage on all contactor lugs to ensure proper orientation.

3.

If a contactor is regularly clicking, inspect the wiring.

Compressor rubbing against neighboring metal bracket/shelf.

1.

Remove the side panel closest to the front of the compressor.

2.

Use work light to identify any potential interferences around the compressor.

• If interference is identified: Loosen bolts holding shelf and slide bracket (shelf has mounting slots) further away from compressor. Remove interference, retighten shelf bolts, and replace side panel.

Radiator/compressor rubber isolators damaged.

1.

Remove the side panel closest to the front of the compressor.

2.

Use a work light to identify any potential damage to the four isolators holding up the compressor.

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Observed symptoms

Excessive noise (continued) Observed issue: (continued) Possible cause (continued) • If rubber isolator damage is identified: Remove compressor, replace damaged isolator, Install compressor, and side panel.

Coolant pump damage 1.

Remove the side panel closest to the coolant pump.

2.

With pump running, listen for any abnormal vibrations or whines coming from coolant pump.

3.

If noise is detected from the pump, drain the coolant system, and replace pump. Reinstall the side panel.

Air filter is clogged 1.

Remove front panel and with system running, remove air filter momentarily to see if compressor speed reduces.

• If spare air filter is present, install new air filter to confirm lower compressor operation.

• Reinstall the front panel.

Odor/Smoke/Sparks/Flame

Observed issue:

There is odor, smoke, sparks or flames coming from the FCS. Possible causes A component in the system is overheating or has failed.

1.

Press the E-stop button and move away from the FCS.

The cable exiting the system is damaged.

1.

Inspect the output cables from the unit for damage, cuts, or abrasions in the insulation.

The Anderson Connector is loose fitting or damaged.

1.

Excessive wear or poor terminal crimps can overheat the Anderson connector plastic and cause melting or burning plastic.

2.

Inspect plastic for heat.

3.

Unplug Anderson connector and visually inspect terminal mating surfaces for arcing, weld, or heat witness marks.

Loose busbar connection inside the FCS. 1.

Power FCS off. Engage the E-stop.

2.

Remove both side panels and inspect all copper busbars for signs of discoloration and/or burning smell.

• If discolored or visibly loose busbar, or obvious burn smell is identified, remove busbar, and inspect for any melted copper. If copper is not damaged in any way, busbar can be reinstalled to specified torque.

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Observed symptoms

Odor/Smoke/Sparks/Flame (continued) Observed issue: (continued) Possible causes (continued) • Reinstall side panels.

Overheated supply valve.

1.

Power FCS off. Engage the E-stop.

2.

Remove front panel and inspect small cylindrical valve on the tank regulator, just below the red hydrogen line.

• Inspect stainless valve for any signs of discoloration or burning smell.

• If temperature device is available, measure temperature of the outside surface for elevated temperatures.

• If any signs point to an overheating even, replace supply valve.

• Reinstall front panel.

Fluids leaking from FCS

Observed issue:

There is visible fluid coming from the FCS. Possible causes Coolant leak (broken/loose fitting).

1.

Power FCS off. Engage the E-stop.

2.

Remove both side panels and inspect for signs of a leak along any of the green silicone hoses or the components (barbs, sensors, manifolds, radiator) connected to the hoses.

• If a leak is identified at any point through the coolant system, drain the system and replace any broken or loose part. See Nuvera® Fuel Cell System Service Manual for procedure.

3.

Refill the cooling system and reinstall side panels.

Coolant drain valve(s) not fully closed.

1.

Power FCS off. Engage the E-stop.

2.

Remove side panel to the right of the front panel as well as back panel.

3.

Inspect black drain valve on the side of the casting for any coolant drips.

4.

Inspect drain on the back of the radiator for any coolant drips.

• If the valve or plug is leaking, drain the system and replace affected part. See Nuvera® Fuel Cell System Service Manual for procedure.

• Refill the cooling system.

• Reinstall the panels.

Product water is leaking from the humidifier/stack/reservoir has a loose or broken connection.

1.

Power FCS off. Engage the E-stop.

2.

Remove both side panels and inspect all blue silicone hoses as well as the components connected by the blue hoses for any signs of water leakage and damage.

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Observed symptoms

Fluids leaking from FCS (continued) Observed issue: (continued) Possible causes (continued) • If any components are found to be loose or broken, replace affected component. See Nuvera® Fuel Cell System Service Manual for procedure.

• Reinstall the panels.

Reservoir drain valve is stuck open 1.

Inspect drain valve at the front panel of the system for any signs of leakage from the front side or the back side of the valve.

• If any components are found to be loose or broken, replace affected component. See Nuvera® Fuel Cell System Service Manual for procedure.

• If water continues to leak from front of port or is visibly leaking from backside hose barb connection, remove right side panel and replace drain valve. See Nuvera® Fuel Cell System Service Manual for procedure.

2.

Reinstall side panel.

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Nuvera® Fuel Cell System Diagnostic Troubleshooting Manual

Piping and instrumentation and wiring diagrams

Wiring diagrams

Figure 12. Sheet 1 of 8 98

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Nuvera® Fuel Cell System Diagnostic Troubleshooting Manual

Piping and instrumentation and wiring diagrams

Wiring diagrams (continued)

Figure 13. Sheet 2 of 8 99

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Nuvera® Fuel Cell System Diagnostic Troubleshooting Manual

Piping and instrumentation and wiring diagrams

Wiring diagrams (continued)

Figure 14. Sheet 3 of 8 100

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Nuvera® Fuel Cell System Diagnostic Troubleshooting Manual

Piping and instrumentation and wiring diagrams

Wiring diagrams (continued)

Figure 15. Sheet 4 of 8 101

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Nuvera® Fuel Cell System Diagnostic Troubleshooting Manual

Piping and instrumentation and wiring diagrams

Wiring diagrams (continued)

Figure 16. Sheet 5 of 8 102

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Nuvera® Fuel Cell System Diagnostic Troubleshooting Manual

Piping and instrumentation and wiring diagrams

Wiring diagrams (continued)

Figure 17. Sheet 6 of 8 103

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Nuvera® Fuel Cell System Diagnostic Troubleshooting Manual

Piping and instrumentation and wiring diagrams

Wiring diagrams (continued)

Figure 18. Sheet 7 of 8 104

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Nuvera® Fuel Cell System Diagnostic Troubleshooting Manual

Piping and instrumentation and wiring diagrams

Wiring diagrams (continued)

Figure 19. Sheet 8 of 8 105

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Nuvera® Fuel Cell System Diagnostic Troubleshooting Manual

Piping and instrumentation and wiring diagrams

ESS harness diagrams

Figure 20. Type 1

Figure 21. Type 2

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Nuvera® Fuel Cell System Diagnostic Troubleshooting Manual

Piping and instrumentation and wiring diagrams

ESS harness diagrams (continued)

Figure 22. Type 3

Figure 23. Type 4

107

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Nuvera® Fuel Cell System Diagnostic Troubleshooting Manual

Piping and instrumentation and wiring diagrams

ESS harness diagrams (continued)

Figure 24. Type 5

Figure 25. Type 6

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Nuvera® Fuel Cell System Diagnostic Troubleshooting Manual

Piping and instrumentation and wiring diagrams

Piping and instrumentation diagram

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Figure 26. Sheet 1 of 2

111/(112 blank)

Figure 27. Sheet 2 of 2

113/(114 blank)

Notes

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Nuvera Fuel Cells LLC 129 Concord Road, Bldg. 1 Billerica, MA 01821 USA Tel: (617) 245-7500