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. Check EVAP system vacuum hoses for proper connection, leakage, plugging or deterioration. If vacuum hoses are okay, go to next step. If vacuum hoses are faulty, repair as necessary and repeat DTC CONFIRMATION TEST .
- Check EVAP canister purge valve circuit. See EVAP CANISTER PURGE VALVE CIRCUIT under FUEL EVAPORATION under EMISSION SYSTEMS & SUB-SYSTEMS in SYSTEM & COMPONENT TESTING article. If EVAP canister purge valve circuit is okay, go to next step. If EVAP canister purge valve circuit is faulty, go to step 5 .
- Check EVAP canister for damage. See EVAP CANISTER under FUEL EVAPORATION under EMISSION SYSTEMS & SUB-SYSTEMS in SYSTEM & COMPONENT TESTING article. If EVAP canister is okay, go to next step. If EVAP canister is faulty, replace EVAP canister and repeat DTC CONFIRMATION TEST .
- Perform EVAP canister purge control valve component test. See EVAP CANISTER PURGE VALVE under FUEL EVAPORATION under EMISSION SYSTEMS & SUB-SYSTEMS in SYSTEM & COMPONENT TESTING article. If EVAP canister purge control valve is faulty, replace purge control valve and repeat DTC CONFIRMATION TEST . If EVAP canister purge control valve is okay, substitute ECM with a known good unit and repeat DTC CONFIRMATION TEST .