The crankshaft sensor tells the control unit the speed and phase of the engine: if the signal does not arrive, injection and ignition do not start and the car will not start or will stall.
Typical symptoms
- Car does not start although the starter turns
- Sudden stalling, often when hot
- Rev counter drops to zero or flickers
- Intermittent starting: sometimes it starts, sometimes it does not
- Check engine light with code P0335
Why it fails
- Heat and ageing of the internal coil
- Damaged, oxidised or bent connector or wiring
- Dirt or metal debris on the magnetic tip
- Wrong air gap or damaged reluctor ring
How to test it
- Read the speed signal during cranking and when hot.
- Check connector and wiring, with hot and cold tests.
- Measure sensor resistance and signal where applicable.
- Check reluctor ring and air gap.
A trap: a fault that shows "only when hot"
The sensor can work when cold and fail as soon as it warms up: the car stalls after a few kilometres and restarts half an hour later. It is the feature that distinguishes it from a battery or fuel problem. A hot diagnosis finds it.
How much does it cost to fix?
| Work | Indicative cost |
|---|---|
| Crankshaft sensor | €60-200 |
| Wiring / connector repair | €50-250 |
| Diagnosis | €50-120 |
Figures are indicative market ranges, useful for orientation: the real cost depends on model, engine, parts chosen and labour hours. For an exact quote we need the vehicle registration number.
How MasterTuning helps
We read the real values of the control unit, not just the code: that is the difference between finding the faulty component and replacing parts by trial and error. After the repair we clear the error and check that it does not come back. Find the nearest centre or contact us.
Does the car stall or not start when hot? Book a diagnosis at the nearest MasterTuning centre.
Frequently asked questions
How do I know the crankshaft sensor is faulty?
A rev counter at zero when cranking, sudden stalling and code P0335 are the typical signs.
Can it fail only when hot?
Yes: it is a classic failure, the car stalls after a while and restarts after cooling.
How much does it cost to replace?
Usually €60-200 for part and labour, depending on the model.
Can I drive with a faulty crankshaft sensor?
It is not recommended: the car can stall while driving, losing power steering and brake assistance.
