The camshaft position sensor tells the computer which stroke each cylinder is on, which is what allows sequential fuel injection and correct ignition timing. Unlike a crankshaft sensor failure, many engines can still limp along without a good camshaft signal, just running worse.
Symptoms
- Hard starting, especially a longer crank time before the engine catches
- Rough idle and reduced power
- Occasional stalling, though usually less abrupt than a crankshaft sensor failure
- Reduced fuel economy
Likely causes
- Failed camshaft position sensor — the most common cause
- Damaged or corroded wiring or connector at the sensor
- Timing chain/belt wear that's thrown the camshaft slightly out of its expected position
- Oil-fouled sensor tip on engines where the sensor sits close to moving parts
How to diagnose it
- Inspect the sensor connector and wiring for corrosion or damage first
- Test the sensor signal with a scan tool while cranking or idling
- If timing-chain wear is suspected (rattling noise on startup), check timing marks/chain stretch before condemning the sensor
Typical fixes & cost
- Replace the camshaft position sensor70–250 EUR
- Repair wiring or connector60–200 EUR
- Timing chain/belt service, if that's the underlying cause400–1200 EUR
Code names are compiled from open/standardized SAE and ISO references. Explanations, symptoms, causes and fixes are original. Covers generic (P0/C0/B0/U0) codes only — manufacturer-specific codes are planned for a future update.
AS
Reviewed by Artyom SemenovAutomotive Editor · Fact-checked by Yauheni Kapliarchuk, Editor-in-Chief