P0339 — Crankshaft Position Sensor A Circuit Intermittent
The crankshaft position sensor A signal jumps or drops out intermittently — connector, sensor air gap, or damaged tone wheel. The PCM may detect a "false" stall or misfire spike when the signal drops.
General code reference. Confirm the definition and diagnostic procedure for your vehicle's year, model and engine. A stored code alone does not identify a failed part.
Affected components
- Crankshaft position sensor
- Flywheel
Possible causes to check
These are possible checks, not a ranked diagnosis. Follow the vehicle manufacturer's test procedure before replacing parts.
- Intermittent connector
- Tone wheel chipped or contaminated
- Connector with intermittent contact under vibration
Diagnostic notes
- The malfunction indicator lamp may illuminate
- This code can affect emissions
Related codes
Sources
Check each reference's vehicle and model-year scope. General background links do not establish which fault is most likely on your vehicle.
Diagnostic information is provided for reference only. Confirm the code with a compatible scan tool and follow the vehicle manufacturer's service procedures before replacing components.