Diagnosis & Repair Procedure
NOTE:
For better performance and results of this diagnostic procedure, usage of appropriate wiring diagram is recommended. See ENGINE PERFORMANCE in SYSTEM WIRING DIAGRAMS
article in ELECTRICAL.
NOTE:
Perform all voltage and resistance tests using a Digital Volt-Ohmmeter (DVOM) with a minimum 10-megohm input impedance, unless stated otherwise in test procedure. Use an ohmmeter to isolate wiring harness shorts or opens.
- If engine system check has been performed, go to next step. If engine system check has not been performed, perform A-4: ENGINE SYSTEM CHECK under SYSTEM TESTS, then go to next step.
- Turn ignition switch to LOCK position. Located ECM under instrument panel, behind glove box. See Figure . Start engine and let it idle. Backprobe and measure voltage between ground and ECM 35-pin harness connector E61 terminal No. 2 (White wire). See Figure . Voltage should be 10-14 volts. If voltage is as specified, go to next step. If voltage is not as specified, repair open or short circuit in White wire between ECM and fuse box. After repair, repeat DTC CONFIRMATION TEST .
- Turn ignition switch to LOCK position. Check ECM and harness connector for poor, loose, corroded or damaged connector terminals. If connector terminals are faulty, repair as necessary and repeat DTC CONFIRMATION TEST . If connector terminals are okay, check for intermittent problem. See INTERMITTENTS in TROUBLE SHOOTING - NO CODES article. If intermittent problem is found, repair as necessary and repeat DTC CONFIRMATION TEST . If intermittent problem is not found, substitute ECM with a known good unit and repeat DTC CONFIRMATION TEST .