P24FAExhaust Aftertreatment Fuel Air Purge Valve Control Circuit Low
- Generic OBD-II code · Powertrain
- Turns on the check-engine light
- Matters for the ITP
- Can trigger limp mode
- How the car detects it
- P24FA reports that voltage on the purge valve control line is lower than the driver stage expects in the current switching state: a short to ground on the wire, a coil with too little resistance or a weak supply. Volvo and Mack name P24FA00 in the electrical section of their AHI troubleshooting guide for US10+OBD13 and newer engines; the work there is on the dosing module plug and the harness, not on the air or fuel side. Depending on how the driver is wired, a ground short can either keep the valve energised permanently or stop it from switching. In both cases the purge cycle after hydrocarbon dosing becomes unreliable, and the controller may suspend active regeneration until the fault is fixed. An open circuit is P24F8, the opposite polarity P24FB.
- What you may notice
- Warning lamp shortly after key-on or during dosing
- Regeneration not possible
- Likely causes
- LikelyControl wire chafed through to chassis ground
- PossiblePurge valve coil with shorted turns
- RareMoisture in the AHI module connector
- 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.