P20DB
Exhaust Aftertreatment Fuel Supply Control Stuck Open
Aftertreatment fuel supply solenoid stuck open mechanically — fuel pressure cannot be cut off, risk of over-fueling exhaust.
- 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 openCommon
- Carbon or debris buildup preventing free movementLess likely
- Component wear with age - mechanical playLess likely
Parts involved
- Aftertreatment Fuel Supply Solenoid
P20DB 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.