Powertrain, generic (extended)

P20CE Exhaust Aftertreatment Fuel Injector A Control Circuit High

Check engine lightOn
EmissionsRelevant
Drive cycleNot required
Limp modePossible

The control line of the hydrocarbon doser is shorted to battery voltage. GM's diesel tables 18OBDG04 and 25OBDG04A detect it while the driver is switched on: current above roughly 8 to 11 A for a set time, or above about 16 to 22 A at once, counts as a short to power. GM rates it Type B, so the MIL follows after two trips; the LML/LGH Duramax (15OBDG09) uses a voltage check in the on state. The doser can then no longer be opened on command. Hino's J08E manual names P20CE among the codes to clear before diagnosing a regeneration complaint. Open circuit and short to ground are P20CB and P20CD.

Likely causes

Control wire touching a powered wire in a damaged harness
Doser solenoid with shorted turns drawing too much current
Faulty output stage in the engine control module

Symptoms

  • Check engine light on
  • Active regeneration not possible
  • Rising soot load, later reduced power

Repair estimate

DifficultyMediumWorkshop job
Parts and labour€100–900
Time0.5–2.5 h

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

Parts involved

aftertreatment fuel injector

Related codes

P20CBP20CDP20D4P269A

References: gsi.ext.gm.com, gsi.ext.gm.com, static.nhtsa.gov.