P24F9Exhaust Aftertreatment Fuel Air Purge Valve Control Circuit Range/Performance
- Generic OBD-II code · Powertrain
- Turns on the check-engine light
- Matters for the ITP
- Needs a drive cycle to confirm a fix
- How the car detects it
- P24F9 covers a purge valve control circuit that is electrically present but behaves implausibly, for example when measured current or a feedback signal does not follow the commanded state within the expected time. Unlike P24F8, P24FA and P24FB, this variant appears in none of the Volvo/Mack AHI documents, and no manufacturer documents P24F9 publicly. The part involved is the same: a solenoid in the dosing module that admits compressed air to flush fuel out of the line to the exhaust injector after each dosing event. CARB's heavy-duty rule 1971.1 obliges systems that blow fuel into the exhaust with air assistance to detect any failure that leaves the filter unable to regenerate. Plausible triggers are a sluggish valve, drifting coil resistance or a high-resistance contact.
- What you may notice
- Warning lamp, sometimes only under heat
- Irregular or aborted filter regenerations
- Likely causes
- PossiblePurge valve moving slowly because of deposits
- PossibleSolenoid coil resistance drifting with heat or age
- RareHigh-resistance contact in the module plug
- 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: €150 – €1,200
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.