ABS and brakes

C0110 — ABS Pump Motor Circuit Malfunction

Severity: medium Drive with care, to a shop

What C0110 means

The ABS control module (EBCM) monitors the electric motor in the brake pressure modulator, which builds pressure for ABS and stability functions. C0110 sets when the motor's feedback or circuit does not match what the module expects, such as an open, short, poor connection, or a failed motor. The module usually disables ABS and related systems in response.

Symptoms

  • ABS warning light on
  • Traction or stability control lights may also come on
  • Reduced or unusual braking performance
  • Hard or pulsating brake pedal
  • Softer pedal on some vehicles
  • ABS does not activate in hard braking

Possible causes

  1. Failed ABS pump motor in the modulator assembly
  2. Open, shorted, or poor connection in the pump motor circuit
  3. Faulty or corroded pump relay or blown fuse
  4. Internal fault in the ABS control module (EBCM)
  5. Low battery voltage during the ABS self-test
  6. Low brake fluid or an unrelated sensor fault (less likely)

How to diagnose

  1. Scan all modules, record the ABS codes and freeze-frame data
  2. Check brake fluid level and condition
  3. Test battery voltage and charging output, and inspect terminals and grounds
  4. Locate and test the ABS pump fuse and relay, swapping in a known good relay if needed
  5. Inspect the modulator connector and wiring for corrosion, moisture, and damage
  6. Check for power and ground at the pump motor connector using the wiring diagram
  7. Run the scan tool's pump activation test if supported
  8. If the circuits are good, suspect the pump motor or the ABS module

Common fixes

  • Replace the blown fuse or faulty pump relay
  • Repair or replace damaged wiring and connectors, and clean contacts and grounds
  • Replace the ABS pump/hydraulic modulator assembly
  • Replace or reprogram the ABS control module
  • Charge or replace a weak battery

Questions and answers

Can I drive with code C0110?

Yes, with caution. The base brakes still work, but ABS and stability control may be disabled. Leave extra following distance and get it diagnosed soon.

What most often causes C0110?

Commonly a blown fuse, a bad relay, a poor connector contact, or a worn pump motor. Start with the fuse, relay and wiring before replacing expensive parts.

Can I just clear C0110 and keep driving?

Clearing only turns off the light temporarily. If the fault is still there the code will return, and ABS will not work properly.

This is general information about the code. The meaning can differ between makes and models: a scan tool and the repair manual for your car will show the exact cause.