Eaton Top 2 Transmissions

18.6 Eaton Top 2 Transmissions

The Caterpillar ECM operates two solenoids to control the shifting between the top two gears of an Eaton Top2 Transmission. This requires programming of four Customer Parameters and additional wiring. Caterpillar recommends Locking each of these parameters following their programming for Eaton Top 2. Each of the parameters must be correctly programmed for the system to operate correctly. OEM provided and installed components required: 1) Connection to ECM J1/P1 terminal-20 to a Shift Solenoid and to J1/P1 terminal-19 to a Lockout Solenoid. Customer Parameter programming required: 1) Transmission Style parameter programmed to Eaton Top2. 2) Top Gear Ratio. 3) Top Gear Minus One Ratio. 4) Top Gear Minus Two Ratio.

18.6.1 Output #6 and Output #7 Electrical Specifications

Electrical characteristics of these high side drivers are as follows:

Minimum “ON” Output Voltage Maximum “ON” Output Voltage Maximum Current Draw OFF State Battery - 2.0 Volts DC Battery 1.0 A High Impedance

These driver are intended for connection to a solenoid. Caterpillar recommends transient suppression be used on the inductive load in addition to the ECM’s internal protection. Circuit protection is left to the OEM’s discretion. Connection for this output:

Terminal Description ECM Terminal Assignment Output #6 Terminal 19

Output #7 Terminal 20

18.6.2 Lockout Solenoid Operation

The Lockout Solenoid uses Output #6 when the Transmission Style is programmed to Eaton Top 2.This output will be ON when the ECM detects an Eaton Top 2 transmission is in the programmed Top Gear Minus One Ratio and OFF under all other conditions. A 54-05 Output #6 Open Circuit (66) diagnostic code will be active if the Transmission Style is programmed to Eaton Top 2 without connection to the solenoid or if a fault condition exists for the Lockout Solenoid.

18.6.3 Shift Solenoid Operation

The Shift Solenoid uses Output #7 when the Transmission Style is programmed to Eaton Top 2. This output will be ON when the ECM detects an Eaton Top 2 transmission is in the programmed Top Gear Ratio and OFF under all other conditions. A 55-05 Output #7 Open Circuit (67) diagnostic code will be active if the Transmission Style is programmed to Eaton Top 2 without connection to the solenoid or if a fault condition exists for the Shift Solenoid.