Powertrain, generic (extended)

P2401 EVAP System Leak Detection Pump Control Circuit Low

Check engine lightOn
EmissionsRelevant
Drive cycleRequired
Limp modeNo

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.

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

Symptoms

  • Check engine light
  • Leak test not completed, EVAP readiness missing

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

P2400P2402P2405

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