P1391

Test 1:

Test 2 - 5:

Test 6 - 9:

Test 10 - 11:

SYMPTOM
P1391-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
- Good trip equal to zero
- Checking intermittent CMP signal with lab scope
- CMP wire harness inspection
- Tone wheel/pulse ring inspection
- CKP wire harness inspection
- Tone wheel/pulse ring inspection
- Checking intermittent CKP signal with lab scope
- Camshaft position sensor
- Crankshaft position sensor