What are the causes of P0012 Camshaft Position A Timing Over-Retarded?
2 Answers
p0012 camshaft position a timing over-retarded causes are as follows: 1. Low gasoline octane rating or engine misfire: Causes engine detonation leading to camshaft delay, altering position sensor signal data. 2. OCV valve malfunction: Possibly stuck OCV valve causing failure in the engine's intake valve oil control valve. 3. Oil control valve failure: Oil pressure control valve OCV stuck. 4. Abnormal CVVT control circuit current: CVVT actuator gear mechanically jammed. 5. Oil pump wear: Oil pump pressure regulator valve stuck or system clogged.
I've repaired several vehicles reporting P0012 faults and found that timing lag is most commonly caused by chain elongation. Nowadays, many cars use chains instead of belts, which tend to stretch after about 100,000 kilometers, especially those that make rattling noises during cold starts. Another issue is with the engine oil. Once, I changed the oil to a 20 viscosity grade for a customer, but the VVT solenoid valve got stuck due to insufficient oil pressure, and it was only resolved after cleaning the solenoid valve. Additionally, leaks in the crankcase ventilation valve can disrupt pressure. I once detected this hidden issue when measuring vacuum levels. Sensor failures are relatively rare, but if the data stream shows significant phase deviation, the chain sprocket needs to be checked, which can cost three to four thousand in labor fees.
