Fault code P0321 – a step-by-step guide to diagnosing and fixing it

Error code P0321 is displayed and the check engine light is on - what does this mean?

The DTC P0321 indicates a problem with the crankshaft position sensor, where the OBD system detects an implausible range or insufficient performance of the sensor. This trouble code affects the engine management system and can occur with slightly different definitions for different manufacturers, although the basic problem with the crankshaft sensor remains the same.

What causes can this error code have?

• Defective crankshaft position sensor
• Damaged or corroded cable connections to the sensor
• Loose or dirty plug connections
• Defective pulse generator wheel on the crankshaft
• Excessive air gap between sensor and pulse generator
• Contamination of the sensor by metal shavings or oil
• Defective engine control unit (ECU)
• Interrupted or short-circuited wiring

What symptoms occur in parallel with fault code P0321?

• Starting problems: The vehicle is difficult or impossible to start because the engine control unit cannot correctly detect the crankshaft position.
• Engine misfires: Irregular engine running with noticeable jerking, especially when idling or at low engine speeds.
• Loss of power: Significantly reduced engine power and poor acceleration due to incorrect ignition timing.
• Engine stalls: Sudden stalling of the engine while driving, especially at low revs or idling.
• Increased fuel consumption: Poorer fuel efficiency due to inaccurate injection timing and ignition.

How to fix the problem of fault code P0321?

• Repairing fault code P0321 requires a systematic approach to identify the exact cause.
• Replace the crankshaft position sensor: Locate the defective sensor, remove it and replace it with a new original part, ensuring the correct air gap to the pulse generator.
• Clean and secure plug connections: Check all electrical connections to the sensor, clean, inspect for corrosion and connect firmly.
• Repair wiring: Identify damaged cables to the crankshaft sensor, repair severed areas or replace complete wiring harnesses.
• Check pulse generator wheel: Check the gear on the crankshaft for damage, missing teeth or dirt and replace if necessary.
• Adjust the sensor air gap: Correctly adjust the gap between the crankshaft sensor and pulse generator in accordance with the manufacturer's specifications.
• Diagnose the engine control unit: If the code occurs repeatedly, check the ECU for defects and have it repaired or replaced if necessary.