Fault in the crankshaft position sensor signal — critical for ignition timing and injection.
SYMPTOMS
- Check-engine light
- Hard start or no-start
- Stalling
- Intermittent cut-out
- Tach dropout
LIKELY CAUSES
- Failed crank sensor
- Wiring/connector fault
- Damaged reluctor/tone ring
- Metal debris on the sensor
DIAGNOSIS STEPS
- Scope the sensor signal while cranking
- Check wiring and connector
- Inspect tone ring and air gap
RELATED PARTS
- Crankshaft position sensor