Powertrain, generic (extended)

P20D7 Exhaust Aftertreatment Fuel Supply Control Circuit/Open

Check engine lightOn
EmissionsRelevant
Drive cycleNot required
Limp modePossible

Upstream of the exhaust doser sits a valve that releases fuel to it only when a regeneration is wanted, often called the shutoff or fuel cut valve. This code reports an open in its control circuit. Volvo and Mack store it as P20D713 (failure type 13 = open) and, in troubleshooting guide KC-2157, send the technician to the wiring and connector of the AHI module, where this valve is housed. Hino's J08E trucks use a fuel cut valve of the same kind. With the valve circuit open, no fuel reaches the doser and active regeneration stops. Shorts are P20D9 (low) and P20DA (high); mechanical sticking is P20DB and P20DC.

Likely causes

Loose or corroded connector at the dosing module
Broken wire in the dosing module harness
Open coil in the fuel shutoff valve

Symptoms

  • Check engine light on
  • Active regeneration not possible
  • Soot warning, later reduced power

Repair estimate

DifficultyMediumWorkshop job
Parts and labour€100–1,200
Time0.5–2.5 h

Typical range across vehicles; the real cost depends on what the testing finds.

Parts involved

aftertreatment fuel supply solenoid

Related codes

P20D9P20DAP20D8P20DBP20DCP0005

References: static.nhtsa.gov, static.nhtsa.gov, law.cornell.edu.