Powertrain, generic (extended)

P2400 EVAP System Leak Detection Pump Control Circuit/Open

Check engine lightOn
EmissionsRelevant
Drive cycleRequired
Limp modeNo

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.

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

Symptoms

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

Repair estimate

DifficultyMediumDIY possible
Parts and labour€60–450
Time0.5–2 h

Typical range across vehicles; the real cost depends on what the testing finds.

Parts involved

evap leak detection pumpevap pump wiring

Related codes

P2401P2402P2404P043E

References: gsi.ext.gm.com, static.nhtsa.gov, static.nhtsa.gov, static.nhtsa.gov.