P20DC
Exhaust Aftertreatment Fuel Supply Control Stuck Closed
Aftertreatment fuel supply solenoid stuck closed — HC dosing into exhaust fails, regeneration cannot raise temperature.
- Check engine light: Yes
- Emissions related: Yes
- Repair difficulty: hard
Common causes
Ordered by how often each turns out to be the cause.
- Solenoid stuck closedCommon
- Carbon or debris buildup preventing free movementLess likely
- Component wear with age - mechanical playLess likely
Parts involved
- Aftertreatment Fuel Supply Solenoid
P20DC is a generic OBD-II code defined by SAE J2012. Exact wording and diagnostic procedure vary by manufacturer and model. Code definitions are drawn from the public-domain OBDex dataset; the workshop notes are our own.