Ecu Power Source Circuit
- Check condition of RR WIP, RADIO NO. 2, P FR DOOR, and GAUGE fuses located in instrument panel junction block, under left side of instrument panel. If fuses are okay, go to next step. If fuse(s) are faulty, replace appropriate fuse and retest system operation.
- Turn ignition on. Using a voltmeter, measure voltage between the following ECU connector terminals. See Figure.
- Connector B5, terminal No. 8 (WIG) and connector B5, terminal No. 9 (GND1).
- Connector B8, terminal No. 18 (ACC) and connector B5, terminal No. 9 (GND1).
- Connector B8, terminal No. 5 (IG) and connector B5, terminal No. 9 (GND1).
- Connector B5, terminal No. 8 (WIG) and connector B8, terminal No. 2 (GND2).
- Connector B8, terminal No. 18 (ACC) and connector B8, terminal No. 2 (GND2).
- Connector B8, terminal No. 5 (IG) and connector B8, terminal No. 2 (GND2).
If voltages are not 10-14 volts, go to next step. If voltages are 10-14 volts, go to next test listed in appropriate SYMPTOM DIAGNOSIS table under TROUBLE SHOOTING .
- Turn ignition off. Disconnect body control ECU connector (located under left side of instrument panel). Turn ignition on. Using a voltmeter, measure voltage between the following ECU connector terminals.
- Connector B8, terminal No. 4 (BSUB) and connector B5, terminal No. 9 (GND1).
- Connector B5, terminal No. 2 (BECU) and connector B5, terminal No. 9 (GND1).
- Connector B8, terminal No. 4 (BSUB) and connector B8, terminal No. 2 (GND2).
- Connector B5, terminal No. 2 (BECU) and connector B8, terminal No. 2 (GND2).
If voltages are not 10-14 volts, go to next step. If voltages are 10-14 volts, go to next test listed in appropriate SYMPTOM DIAGNOSIS table under TROUBLE SHOOTING .
- Check circuits for faults between body ground and body control ECU. See WIRING DIAGRAMS . Repair or replace as necessary. If circuits are okay, check and repair circuits between body control ECU and battery. Retest system operation.