Code Definition

P0012 — Camshaft Position A - Timing Over-Retarded Bank 1

System: Powertrain  |  Type: Generic (OBD-II Standard)  |  Make: Toyota

About P0012

P0012 is a generic (obd-ii standard) powertrain diagnostic trouble code recorded for Toyota vehicles. It belongs to the P-prefix family of codes, which covers engine, transmission, emissions, or fuel-system faults.

When P0012 is stored, the module has detected a bank-specific fault, meaning it applies only to one cylinder bank of a multi-bank engine.

Scanning & clearing: A generic OBD-II scan tool will usually read and clear powertrain (P) codes. For live data, freeze-frame capture, and bi-directional tests you may need a more capable scan tool that supports the vehicle's ECM protocol.

Because P0012 is a generic OBD-II code, its base definition is shared across manufacturers. The specific diagnostic steps, reference values, and repair procedures can vary by vehicle, and the TaT Diagnostic Assistant includes verified procedures submitted by working technicians.

Code Information

The P0012 code is set when the Engine Control Module (ECM) detects that the intake camshaft on Bank 1 is more retarded than the commanded target position, or that the Variable Valve Timing (VVT) phaser fails to advance when commanded. The ECM monitors actual camshaft timing through the Bank 1 camshaft position sensor and compares it against the crankshaft reference signal, calculating cam advance in degrees relative to a target map held in memory. Cam timing is regulated by oil pressure acting on a phaser on the intake camshaft, with oil flow metered by an Oil Control Valve (OCV) that the ECM ...

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