Exhaust Aftertreatment Fuel Air Purge Valve Stuck Closed
The aftertreatment HC dosing or reductant purge valve is stuck closed. The ECM commands purge but the line is not cleared, leaving residual fluid that can foul nozzles or freeze in cold weather. Subsequent dosing events also fail because backpressure does not match the model.
Affected components
- Aftertreatment purge valve
- Dosing line
Common causes
- High likelihood: Stuck closed by deposits or seized armature
- Medium likelihood: Open coil — valve never opens
- Low likelihood: Carbon or debris buildup preventing free movement
Diagnostic notes
- The malfunction indicator lamp may illuminate
- This code can affect emissions
Related codes
Sources
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.