Summary
P0012 means the intake camshaft on Bank 1 is positioned more retarded (delayed) than the PCM is commanding. The most common causes are dirty or low engine oil (30%), a stuck VVT solenoid (30%), and a stretched timing chain (15%). Like P0011, start with an oil level and condition check — sludge-related VVT problems are extremely common and the cheapest fix.
Severity: Moderate — reduced power, poor fuel economy
Safe to drive: Yes, short distances — reduced performance expected
Repair cost: $30–$500 depending on cause
DIY difficulty: Easy to Moderate
What does P0012 mean?
Your engine's variable valve timing (VVT) system adjusts intake valve timing for optimal performance. The PCM commands the camshaft phaser to advance or retard via a VVT solenoid, then confirms the position using camshaft and crankshaft position sensors. P0012 is set when the actual camshaft position is more retarded than commanded.
Where P0011 means the cam is stuck advanced, P0012 means it is stuck retarded — the intake valves are opening later than they should. Retarded timing reduces low-end torque and responsiveness. The engine may feel sluggish, especially during acceleration from a stop, and fuel economy typically drops.
This code is common on engines with oil-actuated VVT systems (most modern engines). The phaser relies on clean, properly pressurized oil to move. When oil quality degrades or supply is insufficient, the phaser often defaults to its retarded position because the return spring pushes it there when oil pressure is too low.