P2401 — EVAP Leak Detection Pump Control Circuit Low
Low severityWhat it means
P2401 is stored when the engine control unit sees a fault involving the EVAP leak detection pump circuit. The leak detection pump pressurises the EVAP system so the control unit can test it for leaks; a circuit fault stops that test running. A “low” reading means the signal is stuck near the bottom of its range, which usually points to a short to ground or an internally failed sensor.
Common symptoms
- The live reading sits abnormally low or at zero
- Usually only a check engine light
- EVAP monitor not completing
- Failed emissions inspection
Likely causes
- Signal wire shorted to ground
- Internally failed sensor pulling the signal low
- A failed leak detection pump
- A wiring, connector or fuse fault
What to check first
- Compare the live signal against a known-good range and check for a short to ground
- Command the pump with a scan tool and listen for it run
- Inspect the pump connector and wiring
Can you keep driving?
Safe to drive; it is an emissions fault, but the car will fail an emissions test until repaired.
Frequently asked questions
What is the most common cause of P2401?
The most likely cause is: Signal wire shorted to ground. Several other faults can set P2401 as well, so confirm the real cause with live data and the checks above before replacing any parts.
Can I just clear P2401 and keep driving?
Clearing P2401 with an OBD2 scanner turns the warning light off, but if the underlying fault has not been repaired the code will usually come back within a few drive cycles. Fix the cause first, then clear the code to confirm the repair worked.
How serious is P2401?
P2401 is a low-severity code. It rarely affects how the car drives, but it is still worth fixing so the engine runs efficiently and passes an emissions test.
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