P1391 Intermittent Loss of CMP or CKP

SYMPTOM
P-1391 INTERMITTENT LOSS OF CMP OR CKP

WHEN MONITORED
Engine running over 7 seconds.

SET CONDITION
When the expected cam signal level disagrees with the actual cam signal level.

POSSIBLE CAUSES
- CKP sensor ckt wiring harness intermittent defective
- CMP sensor signal ckt wiring harness intermittent defective
- Camshaft position sensor defective
- Camshaft sprocket defective
- Crankshaft defective
- Crankshaft position sensor defective
- Distributor pulse ring defective
- Flywheel defective
- Camshaft target magnet defective
- Camshaft thrust plates(s) not attached
- CKP sensor connector terminals observed defect
- CMP sensor connector terminals observed def
- PCM conn terminals observed defective (CKP sensor)
- PCM conn terminals observed defective (CMP sensor)
- Camshaft/cylinder head defective