P2401: EVAP System Leak Detection Pump Control Circuit Low
A generic powertrain (engine and transmission) trouble code, same meaning on every brand.
Yes - the leak detection pump only runs when the car is parked.
Symptoms
- Check engine light only
- Emissions test failure
- No symptom while driving
Likely causes, most common first
- Leak detection pump circuit shorted to ground
- Failed pump motor
- Wiring damage under the vehicle
- Corroded connector at the canister
Read P2401 yourself before paying for diagnosis
A basic Bluetooth OBD-II scanner ($20-40) plugs into the port under the dashboard and shows this code with live sensor data on your phone - useful both for confirming the fix and for talking to a shop from an informed position.
What is going on and how it gets diagnosed
P2401 is a low-voltage fault in the circuit driving the evaporative leak detection pump. Some manufacturers test the system by pressurising it with a small electric pump after the car is switched off and parked, rather than by using engine vacuum.
Because the test runs hours after the car is parked, faults here never announce themselves while driving. The pump assembly is normally mounted next to the charcoal canister under the rear of the vehicle, and like everything else in that area it fails through corrosion far more often than through wear.
Repair options and cost
Typical US independent-shop ranges, parts and labor. Dealers run higher; regional labor rates vary.
Owner reports mentioning P2401
“Started car this morning and the check engine light came on. Took to parts store and hooked it up to the computer and found codes (p2401, p043e, p043f, p2402, p2419) everything I have researched comes back to evap canister failure, and possible wiring failure. More research shows these issues causing people getting stranded and others with no problem other then light, and others with a strong gas smell. If this causes a gas smell, then a potential fire hazard is formed.”2007 Toyota Corolla · Jan 2021 · 130,000 mi
Cars that report P2401 most often
Based on mentions of this code in NHTSA owner complaints.
Frequently asked questions
Can I drive with P2401?
Yes - the leak detection pump only runs when the car is parked.
How much does it cost to fix P2401?
Typical US repair costs range from $80 for the simplest fix (leak detection pump) to $700 in the worst case. The right number depends on which cause your car has - see the causes list.
Related codes
The codes closest to P2401. They often appear together, and telling them apart is usually what narrows the diagnosis.
Definition per SAE J2012 standard nomenclature. Symptoms, causes and costs are editorial guidance - always confirm with a diagnosis of your specific vehicle.