Diagnostic Procedures
- Perform ON-BOARD DIAGNOSTIC (OBD) SYSTEM CHECK. See the BASIC TESTING - 3.8L article. Read and record FREEZE FRAME and/or FAIL RECORDS data for each DTC set. Go to next step.
- Attempt to start engine. If engine starts and runs, go to next step. If engine does not start and run, see ENGINE DOES NOT START in the BASIC TESTING - 3.8L article.
- Using scan tool, clear DTC P0336. Start engine and allow to idle for one minute. Read DTCs. If DTC P0336 resets, go to next step. If DTC does not reset, go to DIAGNOSTIC AIDS.
- Disconnect ICM and PCM harness connectors. Check for open or short to ground in 18X reference circuit between ICM and PCM harness connectors. If a problem is found, repair as necessary. After repairs, go to step 11). If no problem is found, go to next step.
- Reconnect ICM connector. Using DVOM, check voltage on 18X reference circuit at PCM harness connector while cranking engine. If voltage is about 3 volts, go to step 8). If voltage is not as specified, go to next step.
- Check for faulty connections at ICM. If a faulty connection is found, repair as necessary. After repairs, go to step 11). If connections are okay, go to next step.
- Replace ICM. After replacing module, go to step 11).
- Check for incorrect harness routing near secondary ignition components, ignition coil arcing to wiring harness or ICM. Check ignition coils for cracks, carbon tracking or other signs of damage. Check for secondary ignition wire(s) arcing to wiring harness. If a problem is found, repair as necessary. After repairs, go to step 11). If no problem is found, go to next step.
- Check for faulty connections at PCM. If faulty connection is found, repair as necessary. After repairs, go to step 11). If connections are okay, go to next step.
- Replace PCM. Program replacement PCM using required equipment. After replacing PCM, go to next step.
- Read and record FAIL RECORDS data for DTC P0336. Operate vehicle within conditions noted in FAIL RECORDS data. Using scan tool, read SPECIFIC DTC. If scan tool displays DTC P0336 FAILED THIS IGN, return to step 2). If scan tool does not display DTC P0336 FAILED THIS IGN, repair is complete.