P2400
EVAP System Leak Detection Pump Control Circuit/Open
Evaporative emissions (EVAP)
Generic OBD-II
Low
What it means
P2400 means the ECM detected an open in the control circuit for the EVAP leak detection pump — the pump used to test the fuel-vapor system for leaks. It's an electrical fault (open wiring, a failed pump, or a bad connector), not a fuel leak, so the car drives normally. It mainly prevents the EVAP monitor from completing until it's fixed.
Low
Can I keep driving? Yes — this is an emissions-monitoring fault with no effect on how the car drives; just fix it before an emissions test.
Common symptoms
What you'll notice
- Check-engine light on
- No change in how the car drives
- May fail an emissions/readiness check
Common causes
Most likely first
- Open circuit in the leak-detection pump control wiringLikely
- Faulty EVAP leak detection pumpCommon
- Corroded or loose connector at the pumpCommon
- Blown fuse feeding the pump circuitLess often
- ECM driver fault (less common)Less often
How to diagnose & fix
Work through it in order
- Read freeze-frame data to see when the fault set.
- Check the leak-detection pump connector and control wiring for an open.
- Verify power and ground to the pump and check related fuses.
- Test the pump solenoid's resistance against spec.
- Replace the leak detection pump if faulty, then clear and re-test.
FAQ
Quick answers
Is it safe to drive with P2400?+
Yes — it's purely an emissions-system circuit fault and won't affect drivability. Repair it before an emissions test so the EVAP monitor can run.
Can I just clear P2400?+
It returns until the open circuit or faulty pump is repaired, because the ECM re-checks the circuit each drive cycle.
Related codes
Often seen with P2400
Read & clear P2400 yourself
Scan your car, confirm the code, and clear it once it's fixed — with OBD DashX on your phone.
✓ Verified name — SAE J2012 / ISO 15031-6Guidance reviewed by OBD DashX