Code Definition

P0340 — Camshaft Position Sensor Circuit Malfunction

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

About P0340

P0340 is a generic (obd-ii standard) powertrain diagnostic trouble code. It belongs to the P-prefix family of codes, which covers engine, transmission, emissions, or fuel-system faults.

When P0340 is stored, the module has detected a sensor-related fault — the reported value from the named sensor is out of spec.

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 P0340 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 powertrain control module (PCM) sets P0340 when it detects an issue in the camshaft position (CMP) sensor circuit. This can be due to a missing or erratic signal, an open or shorted circuit, or an issue with the sensor itself. The CMP sensor provides crucial timing information for fuel injection and ignition, and without a proper signal, engine performance may suffer, leading to hard starting, misfires, or stalling.

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