Camshaft Position Sensor A Circuit Range/Performance (Bank 1 or Single Sensor)
The camshaft position sensor (phase sensor) tells the ECU where each cylinder is in its cycle. It is compared with the crankshaft sensor to inject and fire at the right moment.
What the car has detected
The camshaft signal does not come when the ECU expects it against the crankshaft: it may be the sensor or the timing having moved.
The car may be slow to start or lack power. If you also hear chain rattle at start-up, the timing may be damaged: have it checked soon and do not push the engine.
Symptoms
- Engine warning light on
- Long or hard starting
- Lack of power or jerking
Possible causes
- Failed camshaft sensor
- Broken or shorted wire, or a loose or corroded connector
- Timing out (stretched chain or slipped belt)
- Low oil level or pressure, on engines with variable timing
Checks for the garage
- Check the oil level
- Check the sensor wiring and connector
- Check the timing
Next step
Ask for the camshaft sensor and its wiring to be checked, and for the timing to be verified.
Go to a garage soon. Checking the timing needs garage tools.