P2DDB code meaning
EVAP System Leak Detection Pump Stuck On
Powertrain system Generic code P2Dxx codes Check engine light
What P2DDB means
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.
P2DDB at a glance
- Check engine lightYes, usually on
- Emissions testCan fail
- Limp modeNot expected
- Repair difficultyMedium, DIY possible
- Typical labor0.5 to 2.5 hours
- Clears after repairAfter a drive cycle
Symptoms of P2DDB
- Check engine light on
- Humming from the tank area after the car is switched off
- Leak test results unusable, EVAP readiness incomplete
Common causes of P2DDB
- Most likelyInternal fault of the leak check module (pump or its electronics)
- PossiblePump supply permanently live, e.g. stuck relay or shorted output stage
- Less likelyControl wire chafed against a powered line
Check the most likely causes first. Replacing parts by guesswork is the most expensive way to clear a code.
Parts involved
EVAP leak detection pumpWiring harnessECM
What each part of P2DDB means
| P | Powertrain system: engine, fuel system, ignition, emissions and transmission. |
| 2 | Generic code (second SAE range): it means the same on every make. |
| DB | The exact fault in that area. |
What to do next
- Note P2DDB and any other codes stored with it: several codes together often point to one cause.
- Check for loose connectors and damaged wiring around the parts the code names.
- Check open recalls for your car: some faults are fixed for free by the dealer. Enter your VIN.
- Clear the code only after the repair. If it comes back, the fault is still there.
Buying a used car? Scan it for stored codes before you pay. A recently cleared memory can hide a problem.
Questions about P2DDB
What does P2DDB mean?
P2DDB means "EVAP System Leak Detection Pump Stuck On". P2DDB reports a leak detection pump that keeps running, or keeps moving air, after the engine computer has turned it off. It is a generic code, so it means the same on every make.
Is it safe to drive with P2DDB?
Usually yes, for a short time, if the check engine light is steady and the car drives normally. If the light flashes or the car runs badly, stop and have it checked.
Will P2DDB fail an emissions test?
Yes, it can. P2DDB is emissions-related, so most inspection programs fail a car while it is stored or while the check engine light is on.
How hard is P2DDB to fix?
Difficulty: medium. A typical repair takes 0.5 to 2.5 hours of work. A careful DIY repair is possible with basic tools and a scanner.
Will P2DDB clear itself after the repair?
After the repair the car has to complete a drive cycle (a mix of city and highway driving) before the test runs again. Until then the readiness monitor shows "not ready", which can fail an inspection.