5-82
FI SYSTEM DIAGNOSIS
Step 2 1) Connect the HO2 sensor coupler. 2) Insert the needle pointed probes to the HO2 sensor coupler. 3) Turn the ignition switch ON and measure the heater voltage between W/B wire and ground. 4) If the tester voltage indicates the battery voltage, it is good condition.
2 V
$ Heater voltage: Battery voltage (+ W/B – - Ground) NOTE: Battery voltage can be detected only before starting the engine. ! 09900-25008: Multi-circuit tester set 09900-25009: Needle pointed probe set & Tester knob indication: Voltage (') Is the voltage OK?
YES
NO
• W/B wire open or shorted to ground, or poor a connection. • Recheck each terminal and wire harness for open circuit and poor connection. • If wire and connection are OK, intermittent trouble or faulty ECM. • Replace the ECM with a known good one, and inspect it again. Open or short circuit in the W/B wire. Loose or poor contacts on the ECM coupler (terminal a) or HO2 sensor coupler.
5) After repairing the trouble, clear the DTC using SDS tool. (#5-26)
2 ECM coupler (Harness side) (Black) (Gray)