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 TEST D: ENGINE SYSTEM CHECK under SYSTEM TESTS then go to next step.
- Turn ignition switch to LOCK position. Disconnect EVAP-CPV 2-pin harness connector C28. See Figure. Turn ignition switch to ON position. Measure voltage between ground and EVAP-CPV harness connector C28 terminal No. 2 (Red/Black wire). See Fig 1. If voltage is 10-14 volts, go to next step. If voltage is not 10-14 volts, repair open or short circuit in Black/Black wire between EVAP-CPV, main relay and ECM. After repair, repeat DTC CONFIRMATION TEST .
- Turn ignition switch to LOCK position. Disconnect ECM harness connector C46. See Figure. Check resistance between ground and ECM harness connector C46 terminal No. 6 (Blue/Black wire). See Figure. If resistance is infinity, go to next step. If any resistance is found, repair short to ground in Blue/Black wire between EVAP-CPV and ECM. After repair, repeat DTC CONFIRMATION TEST .
- Turn ignition switch to ON position. Measure voltage between ground and ECM harness connector C46 terminal No. 6 (Blue/Black wire). See Figure. If voltage is zero volt, go to next step. If any voltage is found, repair short to voltage in Blue/Black wire between EVAP-CPV and ECM. After repair, repeat DTC CONFIRMATION TEST .
- Turn ignition switch to LOCK position. Reconnect EVAP-CPV harness connector. Turn ignition switch to ON position. Measure voltage between ground and ECM harness connector C46 terminal No. 6 (Blue/Black wire). See Figure. If voltage is 10-14 volts, go to next step. If voltage is not 10-14 volts, repair open or short circuit in Blue/Black wire between EVAP-CPV and ECM. After repair, repeat DTC CONFIRMATION TEST .
- Turn ignition switch to LOCK position. Perform EVAP-CPV component test. See EVAP CANISTER PURGE VALVE under FUEL EVAPORATION under EMISSION SYSTEMS & SUB-SYSTEMS in SYSTEM & COMPONENT TESTING article. If EVAP-CPV is okay, go to next step. If EVAP-CPV is faulty, replace as necessary and repeat DTC CONFIRMATION TEST .
- Ensure ignition switch in LOCK position and EVAP-CPV harness connector is connected. Disconnect ECM harness connector G04. See Figure. Measure resistance between ECM harness connector G04 terminals No. 8 or 23 (Red/Black wire) and ECM harness connector C46 terminal No. 6 (Blue/Black wire). See Figure. If resistance is less than 40 ohms at 68°F (20°C), substitute ECM with a known good unit and repeat DTC CONFIRMATION TEST . If resistance is 40 ohms or more at 68°F (20°C), repair short circuit in Black/Red or Blue/Black wire between EVAP-CPV, main relay and ECM. After repair, repeat DTC CONFIRMATION TEST .