P20DCExhaust Aftertreatment Fuel Supply Control 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 valve feeding the exhaust doser does not open when a regeneration starts, so the doser receives no fuel. A Hino patent shows how this is recognized: a pressure sensor between the shutoff valve and the dosing valve reads far below a threshold that depends on engine speed. Volvo and Mack list P20DC00 in AHI guide KC-2157 and tell technicians to look at the fuel supply first, then follow the guided diagnostics; a plugged fuel filter can mimic the fault. The electrical side is fine, which separates it from P20D7, P20D9 and P20DA. Stuck open is P20DB. Hino stores a stuck-closed fuel cut valve under P0005 instead.
- What you may notice
- Check engine light on
- Regenerations fail, soot load keeps rising
- Reduced power in later stages
- Likely causes
- LikelyClogged fuel filter or water and dirt in the fuel
- PossibleSupply valve seized shut
- PossibleInternal fault in the dosing module
- 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: €50 – €1,500
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.