P2DDBEVAP System Leak Detection Pump Stuck On
- Generic OBD-II code · Powertrain
- Turns on the check-engine light
- Matters for the ITP
- Needs a drive cycle to confirm a fix
- How the car detects it
- P2DDB reports a leak detection pump that keeps running, or keeps moving air, after the engine computer has turned it off. GM names P2DDB in its 2025 summary tables only as a blocking code for the ELCP leak test, while its own stuck-on check runs as P145D: with the pump commanded off, the switching valve is moved from vent to pump position halfway through the test, and a pressure shift above 1,000 Pa within 8 s, or more than 1,180 Pa of vacuum after 14 s in a later step, shows the pump is still pulling; Type B over two trips. Mitsubishi files a pump stuck on together with stuck off as P24C0. Because a running pump distorts every reference reading, the leak result becomes useless. Hard circuit faults point to P2401 or P2402 first; stuck off is P2DDA.
- What you may notice
- Check engine light on
- Humming from the tank area after the car is switched off
- Leak test results unusable, EVAP readiness incomplete
- Likely causes
- LikelyInternal fault of the leak check module (pump or its electronics)
- PossiblePump supply permanently live, e.g. stuck relay or shorted output stage
- RareControl wire chafed against a powered line
- Inspection (ITP)
- Matters for the ITP. While the check-engine light is on, the car fails the emissions check.
- Repair
- Medium · Often possible to do yourself.Typical cost: €100 – €600
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.