What does code P0012 mean on a Mercedes-Benz and is it safe to drive?
P0012: Camshaft Position A – Timing Over-Retarded (Bank 1). Here's what it means on your Mercedes-Benz, what usually causes it, what repairs typically cost, and how safe it is to keep driving.
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What this code means
The intake camshaft on bank 1 is more retarded than commanded. Usually means the VVT system can't advance the cam, often from oil sludge blocking the actuator circuit.
Common causes for your Mercedes-Benz
- Oil sludge restricting OCV passages
- Failed oil control valve stuck in retard position
- Low oil pressure or wrong oil viscosity
- Timing chain stretched beyond VVT authority
Symptoms
- Check Engine Light
- Hard cold start
- Rough idle, stalling
- Poor power and fuel economy
Typical fixes
- Oil change—use OEM-specified viscosity
- Clean or replace oil control valve
- Replace timing chain components if worn
Repair cost range
For a Mercedes-Benz, repairs for P0012 often fall between $100 and $1200, depending on the cause and whether you use OEM or aftermarket parts. Labor rates vary by location.