OBD-II reference

All 9.533 generic OBD-II codes, explained in detail.

Causes, inspection steps and sources — a comprehensive DIY archive. Created and maintained with love for the detail. Good luck and have fun!

Chassis generic / SAE

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.

SystemChassis
Typegeneric / SAE
GroupC0
Range / number– / 23

Possible causes

  • Wiring shorted to battery voltage high
  • Relay contacts welded closed medium
  • Connector pins corroded - high contact resistance low

Symptoms

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

Inspection / repair

  • Difficulty: medium
  • DIY: shop recommended
  • Estimated cost: 120–800 €
  • Estimated time: 1–3 h
  • Component: abs pump motor
  • Component: pump motor relay
  • Component: control wiring

Sources

References

How to read OBD-II codes

The first letter names the vehicle system, the second digit distinguishes generic from manufacturer-specific, the remaining digits group fault area and number.

PPowertrain: engine, transmission, emissions
BBody: chassis trim, comfort, interior
CChassis: suspension, brakes, steering
UNetwork: CAN, control modules, communication