P2401: EVAP System Leak Detection Pump Control Circuit Low

P2401 means the control line of the leak detection pump is pulled to ground level, usually by chafed insulation touching the body or by an internal pump fault. GM's 2016 Volt table checks the low-side driver while it is switched off; a near-zero impedance of about 0.5 Ohm to controller ground counts as a short, and 20 of 25 samples of 250 ms set a Type B code over two trips. VW's 2014 Golf and Touareg data books use a signal below about 2.15-3.26 V, depending on engine. Land Rover's SSM71298 (LR4, Range Rover Sport) and Subaru's ELCM bulletins also list P2401, Land Rover pointing to a defect inside the DMTL pump when the wiring checks out. Unlike P2400 the circuit is intact but shorted; the leak test is skipped while driving stays normal.

Low severity. Can I keep driving?Yes, you can normally keep driving. If there is a strong smell of gasoline, find the leak before continuing and do not smoke nearby.

Symptoms

Check engine light
Leak test not completed, EVAP readiness missing

Most likely causes

Control wire chafed through and touching ground near the tank or rear wheel arch
Internal short inside the leak detection pump
Water ingress in the pump connector causing a leakage path to ground

What to check, in order

Start with the simplest. You can tick off each step.

Start with the fuel cap: tighten it fully and check its seal
With the connector unplugged, check whether the signal wire is making contact with ground.
Inspect the hoses and connections around the tank and the charcoal canister
Use the scanner to test the purge and vent solenoid valves
Run a smoke test to find small leaks

Good to know

Repair difficulty: medium
It affects emissions.

What each character of P2401 means

P: Powertrain: engine and transmission
2: Generic code: same on every make
4: Emissions
01: Specific fault in that system

Frequently asked questions

Can I keep driving with code P2401?

Yes, you can normally keep driving. If there is a strong smell of gasoline, find the leak before continuing and do not smoke nearby.

What causes code P2401?

The most common causes are: control wire chafed through and touching ground near the tank or rear wheel arch; internal short inside the leak detection pump; water ingress in the pump connector causing a leakage path to ground.

Related codes

Sources

Values and procedures vary by manufacturer. If it affects brakes, steering, fuel or high voltage, see a professional. Updated: 2026-11-04. How we build these pages.