Code Definition

P0338 — Crankshaft Position Sensor A Circuit High Input

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

About P0338

P0338 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 P0338 is stored, the module has detected a signal or supply voltage higher than the expected operating range; and 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 P0338 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 Engine Control Module (ECM) sets this code when the crankshaft position sensor (CKP) signal voltage is higher than the expected range. This may be due to excessive voltage from the sensor, a short to power, or electrical interference in the circuit. A high input condition can result in rough engine performance, misfires, hard starting, or a no-start situation.

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