Diagnostic Procedures
- Did you perform the Diagnostic System Check - Engine Controls? If yes, go to next step. If no, see DIAGNOSTIC SYSTEM CHECK - ENGINE CONTROLS under SELF-DIAGNOSTIC SYSTEM.
- Turn ignition on, with engine off. With scan tool, command the EVAP purge valve to 50 percent, and then to zero percent. Does the EVAP purge valve respond to the commanded state? If yes, go to next step. If no, go to step 4.
- Observe the Freeze Frame/Failure Records for this DTC. Turn ignition off for 30 seconds. Start engine. Operate the vehicle within the Conditions for Running DTC. See CONDITIONS FOR RUNNING DTC . You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records. Did the DTC fail this ignition cycle? If yes, go to next step. If no, see INTERMITTENTS in TROUBLE SHOOTING - NO CODES - 3.4L AZTEK & RENDEZVOUS article.
- Turn ignition off. Disconnect the EVAP purge valve harness connector. Turn ignition on, with engine off. Probe the ignition voltage circuit at the EVAP purge valve harness connector with a test light connected to a good ground. Does the test light illuminate? If yes, go to next step. If no, go to step 11.
- Connect a test light between the control circuit and the ignition voltage circuit of the EVAP purge valve harness connector. With a scan tool, command the EVAP purge valve to 50 percent and then to zero percent. Does the test light turn ON when the EVAP purge valve is commanded to 50 percent and OFF when the purge valve is commanded to zero percent? If yes, go to step 9. If no, go to next step.
- Does the test light remain illuminated with each command? If yes, go to step 8. If no, go to next step.
- Test the control circuit of the EVAP purge valve for an open or short to voltage. Did you find and correct the condition? If yes, go to step 14. If no, go to step 10.
- Test the control circuit of the EVAP purge valve for a short to ground. Did you find and correct the condition? If yes, go to step 14. If no, go to step 13.
- Inspect for poor connections at the harness connector of the EVAP purge valve. Did you find and correct the condition? If yes, go to step 14. If no, go to step 12.
- Inspect for poor connections at the harness connector of the control module. Did you find and correct the condition? If yes, go to step 14. If no, go to step 13.
- Repair the ignition voltage circuit of the EVAP purge valve for an open or a short to ground. Replace fuse, if necessary. After repairs, go to step 14.
- Replace EVAP purge valve. See REMOVAL & INSTALLATION - AZTEC & RENDEZVOUS article. After repairs, go to step 14.
- Replace PCM. See REMOVAL & INSTALLATION - AZTEC & RENDEZVOUS article. Reprogram PCM. See POWERTRAIN CONTROL MODULE under PROGRAMMING. After repairs, go to next step.
- Clear the DTCs with a scan tool. Turn ignition off for 30 seconds. Start engine. Operate the vehicle within the Conditions for Running DTC. Does the DTC run and pass? If yes, go to next step. If no, go to step 2.
- Observe the stored information, Capture Info with a scan tool. Does the scan tool display any DTCs that you have not diagnosed? If yes, see DIAGNOSTIC TROUBLE CODE DEFINITIONS . If no, system is okay.