P24F8Exhaust Aftertreatment Fuel Air Purge Valve Control Circuit
- Generic OBD-II code · Powertrain
- Turns on the check-engine light
- Matters for the ITP
- Can trigger limp mode
- How the car detects it
- P24F8 is the electrical fault of the fuel/air purge valve: the control unit finds the solenoid drive circuit not working, typically an open wire or a coil that draws no current. Volvo and Mack report it as P24F813, the suffix 13 meaning open circuit. In their AHI diagnosis guide for US10+OBD13 engines onward it stands in the electrical fault table together with P24FA and P24FB, and the prescribed work is the AHI module connector and the harness, not the air or fuel supply. The dosing module carries the valve; on newer trucks it sits on the fuel filter housing. While the valve cannot be driven, the doser line is not blown clear after dosing, which puts filter regeneration at risk. CARB's heavy-duty rules require actuators like this to be checked for circuit continuity.
- What you may notice
- Warning lamp right after the circuit test runs
- Active regeneration blocked or incomplete
- Likely causes
- LikelyBroken wire or chafed harness between engine controller and AHI module
- PossibleCorroded or loose plug at the AHI dosing module
- PossibleInterrupted coil of the purge valve solenoid
- Inspection (ITP)
- Matters for the ITP. While the check-engine light is on, the car fails the emissions check.
- Repair
- Medium · Usually a job for a workshop.Typical cost: €100 – €1,200
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.