What this code means

The PCM has detected a synchronization or erratic signal from the crankshaft position (CKP) or camshaft position (CMP) sensors. The signals do not correlate properly, indicating potential timing issues.

Symptoms

• Check Engine Light
• Engine misfires
• Rough idle
• Poor acceleration
• Stalling
• Difficulty starting

Common causes

• Faulty crankshaft position sensor
• Faulty camshaft position sensor
• Damaged reluctor/tone ring
• Timing chain stretched or jumped (common on 4.0L SOHC)
• Faulty starter motor affecting signal
• Wiring damage

Diagnostic steps

1. Test CKP and CMP sensor signals on oscilloscope
2. Inspect sensor gap and reluctor ring
3. Check timing chain condition — especially on 4.0L SOHC
4. Inspect sensor wiring and connectors
5. Verify battery and starter motor condition

Repair notes

Replace faulty sensor. On 4.0L SOHC, inspect timing chain guides — a broken chain guide is a known failure.

Other Powertrain codes on this vehicle