P2401 Evap System Leak Detection Pump Control Circuit Low

Code: P2401
Applies To: Most makes, generic code
Loose Cap Can Set It: Not named in our sources
Typical Fix: $201 at YourMechanic

The leak detection pump circuit voltage is lower than expected.
A shop confirms it with the carmaker's EVAP test and a smoke machine before replacing parts.
Usually yes for now, but get it fixed soon and check for open recalls.

What The Carmakers Call It

EVAP System Leak Detection Pump Control Circuit Low, as printed by Subaru of America
EVAP System Leak Detection Pump Control Circuit Low, as printed by Maserati S.p.A.

Causes Named In Carmaker Bulletins

The leak check module pump can seize for a short time or collect condensation, Subaru released new engine computer files (2015 to 2021 WRX and STI) (source)

No source ranks these by how often they happen, so they are listed as the bulletins give them.

No source ties this to the gas cap.

The brief asked for a Toyota specific P2401 row. We found no Toyota primary source for P2401, so none is shown.

What The Fix Costs

The usual part for this code is the leak detection pump. Published estimates put it at $201 at YourMechanic. The full table with every source and date is on the cost page. A diagnosis first keeps you from paying for a part you did not need, which is why we price what a check engine diagnostic costs before the fix.

Getting The Light To Go Off

After the repair the light goes off once the EVAP test runs and passes on three drive cycles in a row, and the code is erased after 40 warm up cycles, per CARB. The test only runs under set conditions such as a fuel level between about 15 and 85 percent, so it can take days.

P2400Evap System Leak Detection Pump Control Circuit/open P2402Evap System Leak Detection Pump Control Circuit High