Engine and gearbox (P)
P0012: Camshaft Timing Over-Retarded Bank 1
The intake camshaft on bank 1 is not advancing as it should, staying in a retarded position. This can affect engine performance and efficiency.
Checked by a licensed car technician · last reviewed 29 September 2026
Symptoms
- Reduced engine power
- Poor fuel economy
- Rough idle
- Engine misfire
Common causes
- Stuck oil control valve
- Blocked oil passages
- Worn cam phaser
- Low oil pressure
- Faulty camshaft position sensor
How to check it yourself
- Check engine oil level and condition
- Inspect oil control valve for proper operation
- Examine oil passages for blockages
- Test camshaft position sensor
- Inspect cam phaser for wear
Can I keep driving?
The car can be driven, but performance may be reduced. Address the issue soon to avoid further damage.
General guidance, not a professional inspection. Confirm faults with measurements before buying parts, and use a qualified mechanic for brakes, steering, fuel leaks, airbags, and other safety-critical work. Terms and disclaimer