P20D0Exhaust Aftertreatment Fuel Injector A 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
- The exhaust fuel doser is commanded to inject but no fuel gets through, typically because the nozzle tip is plugged. Detection usually relies on line pressure that fails to drop or on too little heat build-up across the oxidation catalyst. Volvo and Mack list P20D0 in their AHI troubleshooting guide KC-2157; the suggested steps are checking the AHI module and fitting a new nozzle after flushing both supply tubes, and the nozzle there is a maintenance part due at 150,000 miles. CARB demands a fault whenever the injection system can no longer reach regeneration. Without dosing the filter keeps filling with soot. Stuck open is P20CF.
- What you may notice
- Check engine light on
- Regenerations fail or are requested constantly
- Soot warning and reduced power
- Likely causes
- LikelyNozzle tip clogged with carbon
- PossibleDosing module or supply valve not passing fuel
- RareKinked or blocked fuel line to the nozzle
- 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.