P2400: EVAP leak detection pump control circuit open or faulty
The ECU cannot properly control the pump that checks the fuel vapour system for leaks. Usually a wire, connector or the pump itself is at fault.
| Code | P2400 |
|---|---|
| System | Engine and transmission |
| Group | P24xx, EGR, EVAP and particulate filter |
| Type | Generic: it means the same on every make |
| Can you keep driving? | Yes, no rush |
What P2400 means
The EVAP system collects fuel vapour from the tank so it does not escape into the air. Some cars use a small pump to pressurise that system and check it for leaks. The ECU has found an open circuit or electrical fault in the pump’s control line.
Most common causes
- Leak detection pump connector loose or corroded
- Broken or damaged wire between pump and ECU
- Blown fuse or poor supply to the pump
- Faulty leak detection pump
- ECU fault (uncommon)
Symptoms
- Engine warning light on
- Usually no change in how the car drives
- May fail the emissions part of the inspection
Can you drive with P2400?
Yes, no rush It does not affect how the car drives. You can keep using it normally and fix it when convenient, though it may fail an inspection.
How to check it
The pump usually sits near the fuel tank or charcoal canister underneath the rear of the car. Check its connector is fully seated and clean, as it collects road dirt and water.
How to read and clear P2400 with Final OBD
Plug an OBD2 scanner in under the steering wheel, switch the ignition on and open Final OBD. Under Faults you’ll see P2400 with this same explanation and whether it’s confirmed, pending or permanent.
With Free you read this code with its short description for nothing, and clear it if the engine stores it over standard OBD. With Pro you get the full explanation, how the car was running when it was logged (revs, temperature, load) and clearing in every control unit.
Clearing the code only turns the light off: if the cause is still there, it comes back. Clear it once it’s fixed, and not right before the ITV. It’s all in how to read and clear fault codes and in the ITV and OBD.
Similar codes
- P2413 Exhaust gas recirculation (EGR) system performance
- P2414 O2 sensor exhaust sample error (bank 1, sensor 1)
- P2425 EGR cooler valve control circuit open or faulty
- P242F Diesel particulate filter restriction: ash accumulation
- P244A Diesel particulate filter differential pressure too low (bank 1)
- P244B Diesel particulate filter differential pressure too high (bank 1)
- P2452 Diesel particulate filter pressure sensor A circuit
- P2453 Diesel particulate filter pressure sensor A range/performance
P2400 is a generic code, so it means the same on any make, for example on BMW, Fiat, Ford, Mazda, Peugeot, Volkswagen. See what Final OBD does on your car in makes and models.
What does code P2400 mean?
The EVAP system collects fuel vapour from the tank so it does not escape into the air. Some cars use a small pump to pressurise that system and check it for leaks. The ECU has found an open circuit or electrical fault in the pump’s control line.
Can you drive with P2400?
It does not affect how the car drives. You can keep using it normally and fix it when convenient, though it may fail an inspection.
How do you clear P2400?
With an OBD2 scanner and an app like Final OBD, which clears it for free if it’s stored by the engine control unit. But clearing it only turns the light off: if the cause isn’t fixed, P2400 comes back.
Read it on your car
Final OBD reads the faults of every control unit for free, including each make’s own codes, and with Pro explains each one in plain English. Free clears engine faults at no cost.
Coming soon
Mid to late October 2026
If you want to try it in your car before anyone else, send us your email and we will add you as a tester.
info@finalobd.com