P2DDB
EVAP System Leak Detection Pump Stuck On
The EVAP leak detection pump stays running when commanded off. Relay welded or driver stuck on. The evaporative system captures fuel vapor from the tank and purges it into intake; leaks or stuck purge valves leak hydrocarbons and cause emissions failures.
- Check engine light: Yes
- Emissions related: Yes
- Repair difficulty: medium
Symptoms
- Check engine light on
- Possible smell of fuel near tank or engine bay
- Failed emissions inspection
- Loose-cap warning may appear
Common causes
Ordered by how often each turns out to be the cause.
- Relay contacts weldedCommon
- Output driver stuck onPossible
- Carbon or debris buildup preventing free movementLess likely
Parts involved
- EVAP Leak Detection Pump
- Wiring Harness
- ECM
P2DDB 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.