P1391

Test 1 - 2:

Test 3 - 7:

Test 8 - 11:

Test 12 - 13:

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
- Wiring harness inspection
- Tone wheel/pulse ring inspection
- Wiring harness inspection
- Tone wheel/pulse ring inspection
- Checking intermittent crankshaft position sensor signal with lab
- Checking intermittent camshaft position sensor signal with lab
- Checking intermittent CKP wiring with lab scope
- Checking intermittent CMP wiring with lab scope
- Intermittent condition
- Camshaft position sensor
- Crankshaft position sensor