P1391

Test 1:

Tests 2 - 5:

Tests 6 - 9:

Tests 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
- CMP and CKP out of sync
- Checking intermittent CMP signal with LAB
- Harness inspection
- Tone wheel/pulse ring inspection
- Wiring harness inspection
- Tone wheel/pulse ring inspection
- Checking intermittent CKP signal with LAB
- Camshaft position sensor
- Crankshaft position sensor