Diagnostic Procedures
WARNING: This page is about a different car, the 2003 Pontiac Vibe. However, it is still accessible from the selected car via links, so may be relevant.
- Did you perform the Diagnostic System Check - Engine Controls? If yes, go to next step. If no, perform diagnostic system check - engine controls. See DIAGNOSTIC SYSTEM CHECK - ENGINE CONTROLS under SELF-DIAGNOSTIC SYSTEM.
- Are DTCs P1305, P1310, and P1315 also set? If yes, go to step 11. If no, go to next step.
- Start engine. Is an engine misfire present? If yes, go to next step. If no, go to step 9.
- Turn ignition switch to OFF position. Disconnect ignition coil harness connector of the coil indicated by the DTC. Turn ignition switch to RUN position, engine OFF. Probe the ignition positive voltage circuit on harness side of ignition coil connector with a test light connected to ground. Does test light illuminate? If yes, go to next step. If no, go to step 7.
- Use scan tool to clear DTCs. Probe ignition trigger signal circuit on harness side of ignition coil connector with a DMM connected to ground. Measure circuit voltage while cranking engine. Is voltage 0.2-1.0 volt? If yes, go to next step. If no, go to step 8.
- Probe ground circuit on harness side of ignition coil connector with a test light connected to battery voltage. Does test light illuminate? If yes, go to DIAGNOSTIC AIDS . If no, go to step 10.
- Repair open or short in ignition power circuit between the ignition coil and splice SP106. After repair, go to step 18.
- Check low reference circuit of the MAP sensor for an open. Did you find and correct the condition? If yes, go to step 18. If no, go to step 17.
- Check for an open in ignition fail-safe input circuit between the ignition coil and splice SP108. Repair as necessary. Did you find and correct a condition? If yes, go to step 18. If no, go to step 16.
- Repair open in ignition ground circuit between ignition coil and splice SP105. After repair, go to step 18.
- Use scan tool to clear DTCs. Turn ignition OFF for 10 seconds. Turn ignition switch to RUN position, then attempt to start the engine. Did engine start and run smoothly with no engine misfire? If yes, go to step 14. If no, go to next step.
- Turn ignition switch to OFF position. Disconnect harness connector from cylinder 1 ignition coil. Turn ignition switch to RUN position, engine OFF. Probe ignition coil connector ignition positive voltage circuit (harness side) using a test light connected to ground. Does test light illuminate? If yes, go to step 15. If no, go to next step.
- Check for any of the following faults in the ignition positive voltage circuits of ignition coils:
- An open in the circuit between splice SP106 and instrument panel fuse block.
- A short in the circuit between splice SP106, the instrument panel fuse block, or the noise filter.
- A shorted noise filter.
- Check for any of the following faults in ignition fail-safe input circuit:
- An open circuit between PCM and splice SP108.
- A short to ground between PCM and ignition coils.
- A short to voltage between PCM and ignition coils.
- Repair faulty ignition coil ground circuit between splice SP105 and ground point G105. After repair, go to step 18.
- Replace faulty ignition coil. After repair, go to step 18.
- Replace PCM. After repair, go to next step.
- Use scan tool to clear DTCs. Turn ignition OFF for 30 seconds. Start engine. Operate vehicle within CONDITIONS FOR RUNNING DTC as specified. Does DTC run and pass? If yes, go to DIAGNOSTIC TROUBLE CODE DEFINITIONS . If no, system is okay at this time.