P20D6Exhaust Aftertreatment Fuel Injector B 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 second exhaust fuel doser (B) fails to deliver fuel even though the control unit commands it open. No manufacturer documents P20D6 publicly. For doser A, Volvo and Mack handle the matching code P20D0 by checking the dosing module and replacing the nozzle, whose tip tends to clog with carbon; the same weak spot applies to B. A blocked doser means the catalyst stays too cool for regeneration, so soot keeps accumulating in the filter until power is cut back. CARB requires a malfunction once the injection system cannot achieve regeneration. Stuck open on the same doser is P20D5.
- What you may notice
- Check engine light on
- Failed or frequent regenerations
- Reduced power once the filter is heavily loaded
- Likely causes
- LikelyClogged nozzle tip on doser B
- PossibleNo fuel reaching doser B because of a blocked line or closed supply valve
- RareMechanically seized valve in doser B
- 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.