Diagnostic Aids
Perform this test only when directed by QUICK TEST or other test. This test is intended to diagnose the following:
- Crankshaft Position (CKP) sensor.
- Harness circuits: CKP and SIG RTN.
- Powertrain Control Module (PCM).
CIRCUIT PIN IDENTIFICATION
| Circuit | PCM Pin No. | Wire Color |
|---|---|---|
| CKP | 43 | Light Green |
| SIG RTN | 58 | Black/Yellow |
- Check SIG RTN Circuit For Short To Power
Turn ignition off. Disconnect CKP sensor (located near flywheel). Disconnect PCM. Measure resistance of SIG RTN circuit between PCM connector terminal No. 58 (Black/Yellow wire) and VPWR terminal No. 97 (Black/White wire). See Fig 1. Also see CIRCUIT PIN IDENTIFICATION table. If resistance is greater than 10 k/ohms, go to next step. If resistance is less than 10 k/ohms, repair Yellow wire for short to VPWR. Repeat QUICK TEST . - Check CKP Circuit Continuity
Turn ignition off. Ensure CKP sensor and PCM are disconnected. Measure resistance of Light Green wire between CKP sensor connector and PCM connector terminal No. 43. If resistance is less than 5 ohms, go to next step. If resistance is greater than 5 ohms, repair open CKP circuit (Light Green wire). Restore electrical connections and repeat QUICK TEST . - Check CKP Circuit For Short To Ground
Ensure ignition is off. Ensure CKP sensor and PCM are disconnected. Measure resistance between CKP circuit at PCM connector terminal No. 43 (Light Green wire) and negative battery terminal. If resistance measurement is greater than 10 k/ohms, go to next step. If resistance is less than 10 k/ohms, repair Light Green wire for short to ground. - Check CKP SIG RTN Circuit For Short To Power
Ensure ignition is off. Ensure CKP sensor and PCM are disconnected. Measure resistance between CKP circuit at PCM connector terminal No. 43 (Light Green wire) and PCM connector terminal No. 97 (Black/White wire). If resistance measurement is greater than 10 k/ohms, go to next step. If resistance less than 10 k/ohms, repair CKP circuit for short to VPWR. Restore electrical connections and repeat QUICK TEST . - Inspect CKP Sensor Harness Shield
Inspect CKP sensor harness shield for damage. Repair as necessary. Measure resistance between harness shield and chassis ground. If resistance is less than 5 ohms, go to next step. If resistance is greater than 5 ohms, repair open wiring harness shield. Restore all electrical connections and repeat QUICK TEST . - Inspect Flywheel & CKP Sensor For Damage
Inspect flywheel for chipped teeth and inspect CKP sensor for damage. Repair flywheel or CKP sensor as necessary. If flywheel and sensor are okay, restore electrical connections. Clear DTCs. Let engine idle for 4 minutes. If DTC returns, replace PCM. Repeat QUICK TEST .