Diagnosis & Repair Procedure
- If engine system check has been performed, go to next step. If engine system check has not been performed, go to A4: ENGINE SYSTEM CHECK under SYSTEM TESTS.
- Ensure CMP sensor and harness connector for proper installation. If problem is found, repair as necessary. After repair, repeat DTC CONFIRMATION TEST . If CMP sensor and connector are okay, go to next step.
- Turn ignition off. Disconnect CMP sensor 3-pin harness connector. CMP sensor is located in cylinder head near distributor. Check for poor terminal contact at CMP sensor connector. If problem is found, repair as necessary. After repair, repeat DTC CONFIRMATION TEST . If terminal contact is okay, go to next step.
- Turn ignition on. Measure voltage between ground and specified CMP sensor harness connector terminal. See CHECKING CAMSHAFT POSITION SENSOR VOLTAGE
table. See Fig 1
. No. 1 (Red/Black wire). If voltage is not as specified, go to next step. If voltage is as specified, go to step 7
.CHECKING CAMSHAFT POSITION SENSOR VOLTAGE
Measure Between Ground & Terminal No. Specification (Volts) 1 (B+) 10-14 2 (V out) 4-5 3 (GND) Zero - If V out voltage reading was not 4-5 volts, go to next step. If V out voltage reading was 4-5 volts, check for poor connection or short in Black/White wire between CMP sensor and ECM. See WIRING DIAGRAMS article. If no problem with wiring is found, substitute a known good ECM, and repeat DTC CONFIRMATION TEST .
- Check for poor connections or short in Red/Black wire between CMP sensor and ignition switch. Also, check for poor connections or short in Black wire between CMP sensor and ECM. If no problem is found, go to next step. If no problem with wiring is found, repair as necessary. After repair, repeat DTC CONFIRMATION TEST .
- Turn ignition off. Disconnect ECM 26-pin connector C21. ECM is located under instrument panel, behind glove box. See Figure . Check continuity of Black/White wire (V out signal) between ground and CMP sensor harness connector terminal No. 2. See Fig 1 . If continuity exists, go to next step. If continuity does not exist, check for open in Black/White wire between CMP sensor and engine ground. If problem is found, repair as necessary. After repair, repeat DTC CONFIRMATION TEST .
- Remove CMP sensor and check for any metal particles on end face of sensor. Remove particles, if any, and repeat DTC CONFIRMATION TEST . If no particles are found, go to next step.
- Connect CMP and ECM harness connectors. Turn ignition on. Backprobing at ECM, measure voltage between ground and ECM harness connector C20 terminal No. 2 while passing a magnetic substance (iron) about 03" (.76 mm) from end of CMP sensor. See Figure and Fig 2 . Voltage should toggle from 0-5 volts. If voltage is not as specified, replace CMP sensor. After repair, repeat DTC CONFIRMATION TEST . If voltage is as specified, go to next step.
- Using a mirror to view reluctor, check reluctor for damage or foreign material. If problem is found, clean reluctor teeth or replace CMP sensor as necessary. If rotor teeth and CMP sensor are okay, problem is probably intermittent. See INTERMITTENTS in TROUBLE SHOOTING - NO CODES article. After repair, repeat DTC CONFIRMATION TEST .