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C0023

ABS Pump Motor Circuit High

Voltage on the pump motor control line is above the expected range, typically caused by a short to battery voltage or a stuck relay.

  • Check engine light: Not always
  • Emissions related: No
  • Repair difficulty: medium

Symptoms

  • ABS warning light on
  • ESC/stability control deactivated
  • Possible reduced brake assist
  • Speedometer may behave erratically

Common causes

Ordered by how often each turns out to be the cause.

  • Wiring shorted to battery voltageCommon
  • Relay contacts welded closedPossible
  • Connector pins corroded - high contact resistanceLess likely

Parts involved

  • ABS Pump Motor
  • Pump Motor Relay
  • Control Wiring

C0023 is a generic OBD-II code defined by SAE J2012. Exact wording and diagnostic procedure vary by manufacturer and model. Code definitions are drawn from the public-domain OBDex dataset; the workshop notes are our own.