Crankshaft Position Sensor A Circuit Range/Performance
The crankshaft sensor reads a toothed wheel with a gap that marks the reference point. With it the ECU knows the engine speed and when to inject and fire.
What the car has detected
The signal does not have the expected pattern (a tooth missing or extra): sensor, miswired wiring, a damaged toothed wheel or dirt.
Without a reliable crankshaft signal the engine may stall suddenly or not start. If it stalls while driving, stop in a safe place; have it checked as soon as possible.
Symptoms
- Engine warning light on
- The engine stalls suddenly or will not start
- Jerking or lack of power
Possible causes
- Faulty or dirty crankshaft sensor
- Sensor wires swapped or damaged
- Damaged or badly fitted crankshaft toothed wheel
Checks for the garage
- Check the sensor wiring and connector
- Check the sensor signal with an oscilloscope
- Inspect the toothed wheel if the engine has been worked on
Next step
Ask for the crankshaft sensor, its wiring and the toothed wheel to be checked.
Go to a garage as soon as possible. If the car will not start, call for assistance instead of cranking on.