P2400: EVAP System Leak Detection Pump Control Circuit/Open

P2400 is stored when the engine computer finds the drive line of the evaporative leak detection pump open, so the pump cannot be switched for the tank leak test. GM's tables for the sealed fuel system of the Volt (2011, 2016) compare the commanded and actual driver state and treat a low voltage in the off state, equal to more than 200 kOhm to ground, as an open; 20 failed samples out of 25 at 250 ms each set a Type B code. VW's 2014 Golf data book flags a signal voltage of roughly 4.4-5.6 V. Toyota names P2400 with failure types 7E/7F on A25A engines, and VW traced P2400 on the 2011-2014 Touareg 3.6 to coolant entering the pump's vacuum line. P2401 and P2402 are the short-circuit siblings. The leak test cannot run; the car drives normally.

Symptoms

• Check engine light
• EVAP readiness monitor stays incomplete
• No noticeable change in driving behaviour

Most likely causes

• Corroded or loose pump connector, broken wire in the drive line
• Open winding or internal fault in the leak detection pump
• Coolant in the pump's vacuum supply line from a failed coolant pump changeover valve (VW Touareg 3.6)
• Faulty output stage in the engine control module

What to check, in order

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

1. Start with the fuel cap: tighten it fully and check its seal
2. Check the continuity of the wire between the component and the control module.
3. Inspect the hoses and connections around the tank and the charcoal canister
4. Use the scanner to test the purge and vent solenoid valves
5. Run a smoke test to find small leaks

Good to know

• Repair difficulty: medium
• It affects emissions.

What each character of P2400 means

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

Frequently asked questions

Can I keep driving with code P2400?

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 P2400?

The most common causes are: corroded or loose pump connector, broken wire in the drive line; open winding or internal fault in the leak detection pump; coolant in the pump's vacuum supply line from a failed coolant pump changeover valve (VW Touareg 3.6).

Related codes

• P2401EVAP System Leak Detection Pump Control Circuit Low
• P2402EVAP System Leak Detection Pump Control Circuit High
• P2404EVAP System Leak Detection Pump Sense Circuit Range/Performance
• P043EEVAP System Leak Detection Reference Orifice Low Flow

Sources

• gsi.ext.gm.com: 16OBDG01 Hybrid Diagnostics
• static.nhtsa.gov: MC 10073689 2280
• static.nhtsa.gov: MC 10224174 9999
• static.nhtsa.gov: MC 10157825 9999

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.