P24F7
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.
- Check engine light: Yes
- Emissions related: Yes
- Repair difficulty: medium
Common causes
Ordered by how often each turns out to be the cause.
- Stuck closed by deposits or seized armatureCommon
- Open coil — valve never opensPossible
- Carbon or debris buildup preventing free movementLess likely
Parts involved
- Aftertreatment Purge Valve
- Dosing Line
P24F7 is a generic OBD-II code defined by SAE J2012. Exact wording and diagnostic procedure vary by manufacturer and model. Code definitions are drawn from the public-domain OBDex dataset; the workshop notes are our own.