P0338 — Crankshaft Position Sensor A Circuit High

P0338: Crankshaft Position Sensor A Circuit High — what it means, the affected system and what to check before replacing parts.

Meaning, symptoms, causes and checks

Crankshaft Position Sensor A Circuit High. Basic catalogue definition; diagnostic details have not yet been reviewed.

Affected system: Powertrain

Symptoms

  • Engine failing to start
  • Engine stalling while driving
  • Rough engine idling
  • Engine misfires
  • Illuminated Check Engine Light

Possible causes

  • Faulty crankshaft position sensor
  • Damaged or corroded sensor wiring
  • Loose or poor electrical connections
  • Short circuit to voltage in the sensor harness
  • Damaged or missing reluctor ring teeth
  • Internal engine control module (ECU) failure

What to check

  • Inspect the crankshaft position sensor wiring harness and connectors for physical damage.
  • Verify the sensor signal voltage using a multimeter to check for an out-of-range high signal.
  • Measure the resistance of the sensor and compare it with manufacturer specifications.
  • Examine the reluctor ring for debris, missing teeth, or excessive air gap clearance.
  • Test the reference voltage and ground circuit at the sensor connector.

Also written as: P0338-00, P033800, PO338 (some scan tools add the fault-type byte, e.g. -00).