P24F7Exhaust Aftertreatment Fuel Air Purge Valve Stuck Closed
- Generic OBD-II code · Powertrain
- Turns on the check-engine light
- Matters for the ITP
- Can trigger limp mode
- Needs a drive cycle to confirm a fix
- How the car detects it
- P24F7 is the reverse case of P24F6: the purge valve of the aftertreatment fuel/air system will not open when commanded, so no compressed air reaches the dosing line and the 7th injector after a dosing phase. In Volvo and Mack trucks this valve sits in the AHI dosing block, mounted on the fuel filter housing from model year 2017 and on the engine block side before. Volvo's AHI troubleshooting guide points to the air supply, the module and the fuel/air lines up to the nozzle; contamination carried in with the air or fuel causes most module failures. The joint solution for both purge codes was reissued as KC-401 for trucks from model year 2016 and starts with the 221 kPa air pressure check. Without purging, fuel can coke in the line.
- What you may notice
- Active regeneration aborted or not started
- Warning lamp with aftertreatment message
- Possible engine derate as soot load climbs
- Likely causes
- LikelyPurge valve jammed by oil, water or particles from the air system
- PossibleAir supply to the AHI module restricted or below specification
- PossibleCoked or kinked line between AHI module and nozzle
- RareInternal fault of the AHI dosing module
- Inspection (ITP)
- Matters for the ITP. While the check-engine light is on, the car fails the emissions check.
- Repair
- Hard · Usually a job for a workshop.Typical cost: €200 – €1,500
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.