P2401 — EVAP System Leak Detection Pump Control Circuit Low

P2401: EVAP System Leak Detection Pump Control Circuit Low — what it means, the affected system and what to check before replacing parts.

Meaning, symptoms, causes and checks

EVAP System Leak Detection Pump Control Circuit Low. Basic catalogue definition; diagnostic details have not yet been reviewed.

Affected system: Powertrain

Symptoms

  • The engine/emissions warning may be the only visible sign.
  • Ordinary engine performance can remain unchanged despite the EVAP monitor fault.

Possible causes

  • Low electrical input from damaged pump-control wiring, poor ground or corroded connections.
  • A failed leak-detection pump or its driver can also affect the control signal.

What to check

  • Read P2401 together with related EVAP and supply-voltage fault codes.
  • Examine the pump plug, harness, grounds and any accessible fuses for damage.
  • Measure the command-circuit voltage using the vehicle's specified test conditions and verify pump operation before replacement.

Also written as: P2401-00, P240100 (some scan tools add the fault-type byte, e.g. -00).