Diagnostic Procedures
WARNING: This page is about a different car, the 2002 Oldsmobile Intrigue and 2002 Oldsmobile Aurora. 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, go to DIAGNOSTIC SYSTEM CHECK - ENGINE CONTROLS under SELF-DIAGNOSTIC SYSTEM.
- Attempt to start engine. If engine starts and runs, go to next step. If engine does not start, go to step 5.
- Start engine. Select CKP Sensor Status on scan tool. Does scan tool indicate CKP Sensor Status Angle? If yes, go to next step. If no, go to step 5.
- Move the related harnesses and the connectors, by hand only, while monitoring the scan tool display. Does the CKP Sensor Status change to Time "A" or to Time "B", or does an engine stall occur? If yes, go to step 12. If no, see INTERMITTENT CONDITIONS under SELF-DIAGNOSTIC SYSTEM.NOTE: The following steps apply to the sensor and related circuitry that is malfunctioning. For example, it scan tool indicates TIME "A", system is using signal from CKP sensor "A". CKP sensor "B" and related circuits should be diagnosed.
- Turn ignition off. Disconnect CKP sensor. Turn ignition on. Using a Digital Multimeter (DMM) connected to ground, measure voltage on the 12-volt reference circuit at CKP sensor harness connector. Does the DMM indicate battery voltage? If yes, go to next step. If no, go to step 13.
- Connect DMM between the 12-volt reference circuit and low reference circuit in the CKP sensor harness connector. Does the DMM indicate battery voltage? If yes, go to next step. If no, go to step 14.NOTE: In the following step, PCM must be commanded to look at the CKP sensor being tested. Using scan tool, set CRANK POSITION SENSING DECODE MODE to TIME "A"if testing CKP sensor "A", or set mode to TIME "B" if testing CKP sensor "B".
- Turn ignition off and wait 15 seconds. Turn ignition on. Using scan tool, clear DTCs. Using scan tool, command the system to operate in the appropriate Time mode for the sensor being tested. Monitor 24X Crank Sensor Data on scan tool. Using a test light connected to B+, momentarily touch the signal circuit several times. Does scan tool indicate RPM? If yes, go to step 19. If no, go to next step.
- Turn ignition off. Disconnect PCM connector. Turn ignition on. Using DMM, check for presence of voltage on the signal circuit. Does scan tool indicate voltage? If yes, go to step 17. If no, go to next step.
- Using DMM, check signal circuit for continuity between the CKP sensor harness connector and PCM harness connector. Does the DMM display 5 ohms or less? If yes, go to next step. If no, go to step 15.
- Using DMM, check for continuity between the signal circuit and ground. The DMM should display infinite resistance. Does the DMM display infinite resistance? If yes, go to next step. If no, go to step 16.
- Using DMM, check for continuity between the CKP sensor "A" and CKP sensor "B" signal circuits. The DMM should display infinite resistance. Does the DMM display infinite resistance? If yes, go to step 21. If no, go to step 18.
- Repair harness and connections as necessary. After repairs, go to step 21.
- Check and repair the sensor 12-volt reference circuit. After repairs, go to step 23. If no problem is found, go to step 21.
- Check and repair open or high resistance in the low reference sensor circuit. After repairs, go to step 23. If no problem is found, go to step 21.
- Check and repair open or high resistance in sensor signal in the circuit. After repairs, go to step 23. If no problem is found, go to step 21.
- Repair sensor signal circuit that is shorted to ground. After repairs, go to step 23.
- Repair sensor signal circuit that is shorted to power. After repairs, go to step 23.
- Repair signal circuits that are shorted together. After repairs, go to step 23.
- Check for poor connections at CKP sensor connector. Repair connector as necessary. After repairs, go to step 23. If connector is okay, go to next step.
- Replace CKP sensor. After repairs, go to step 23.
- Check for poor connections at PCM connectors. Repair connectors as necessary. After repairs, go to step 23. If connectors are okay, go to next step.
- Replace PCM. Program replacement PCM. See PROGRAMMING . After repairs, go to next step.
- Turn ignition off. Reconnect all disconnected connectors. Turn ignition on. Using scan tool, clear DTCs. Turn ignition off for 30 seconds. Start engine. Operate vehicle within conditions for running the DTC. See CONDITIONS FOR RUNNING DTC . If DTC runs and passes, go to next step. If DTC resets, go to step 2.
- Using scan tool, check for any other DTCs that are set. If no other DTCs are set, system is okay. If any other DTCs are set, repair DTCs as necessary. See DIAGNOSTIC TROUBLE CODE DEFINITIONS .