P1391 Intermittent Loss of CMP or CKP

SYMPTOM
P-1391 INTERMITTENT LOSS OF CMP OR CKP

WHEN MONITORED
Engine running or cranking.

SET CONDITION
When the failure counter reaches 20 for 2 consecutive trips.

POSSIBLE CAUSES
- Recorded lab scope pattern not irregular
- Wiring and connectors observable defect
- Wiring and connectors observable defect
- Sensor defective
- Sensor defective