Drivable short-term with normal brakes working, but ABS is disabled — avoid hard braking on wet or loose surfaces and allow extra stopping distance until repaired. C0110 is a chassis code meaning the ABS control module has detected a fault in the ABS pump motor circuit — it can't properly drive the motor that pressurizes the brake fluid for ABS operation.
What C0110 means
When ABS activates, an electric pump motor in the hydraulic control unit rapidly builds and releases brake pressure at each wheel. The ABS module watches the motor's electrical circuit. C0110 sets when that circuit is open, shorted, or the motor doesn't respond as commanded — because of a failed pump motor, its relay, a wiring or ground fault, or the module's own motor driver. With the pump unavailable the module disables ABS and usually traction and stability control, and lights the warning lamps; your normal (non-ABS) braking still works.
Symptoms
- ABS warning light on, often with traction and stability lights
- ABS does not activate during hard or slippery stops
- No pump buzz/whir during the module's self-test on start-up
- Normal braking unaffected
- Sometimes the fault appears after low-voltage events or a jump-start
Common causes
- Failed ABS pump motor inside the hydraulic control unit
- Faulty ABS pump-motor relay
- Open, shorted, or corroded wiring in the motor power or ground circuit
- Poor high-current ground for the hydraulic unit
- Low system voltage preventing the motor from running correctly
- A failed motor-driver output inside the ABS module
Severity & driving advice
Severity: Moderate — Base brakes still stop the car, but ABS won't work, so wheels can lock in a hard or slippery stop. Fix promptly and leave extra stopping distance.
Can I drive? Drivable short-term with normal brakes working, but ABS is disabled — avoid hard braking on wet or loose surfaces and allow extra stopping distance until repaired.
Diagnostic approach
- Confirm supply voltage first — The pump motor draws heavy current, so a weak battery or bad ground can mimic a motor fault. Verify a healthy battery and clean high-current grounds before condemning the pump.
- Check the motor power and ground circuits — Test for battery voltage at the motor feed and a good ground, and voltage-drop test both under load. Corrosion or a poor ground is a common cause.
- Test the pump-motor relay — Swap or bench-test the relay; a failed relay or its control circuit stops the motor from running even when the motor is fine.
- Command the pump with a scan tool — Use the bidirectional ABS pump/motor self-test. If the motor won't run with good power, ground, and relay, the motor or the module's driver is at fault.
- Decide motor vs module — On most vehicles the pump motor and ABS module are a combined hydraulic unit; if the motor circuit is confirmed bad, the fix is usually the pump/module assembly (or a specialist rebuild).
Estimated repair costs
Typical US repair costs (parts & labour) for the faults behind C0110. These are national-average estimates, not a quote— your actual price varies by region, shop labour rate, and your vehicle’s make, model and year. Figures reviewed 2026.
| Repair | Estimated cost (USD) |
|---|---|
| ABS pump-motor relay | $60–$200 |
| Wiring or ground repair | $80–$350 |
| ABS hydraulic unit / pump-motor assembly (dealer unit may need programming) | $400–$2,500 |
| Diagnosis | $80–$200 |
Make & model notes
General: On most modern vehicles the ABS pump motor is not sold separately — it is part of the hydraulic control unit (HCU) that includes the ABS module. Confirmed motor-circuit failures often mean replacing that assembly or using a specialist rebuild/exchange service, which is far cheaper than a dealer unit.
FAQ
Can I drive with a C0110 code?
Your normal brakes still work, so short, careful driving is generally fine, but ABS is disabled and the wheels can lock during a hard or slippery stop. Allow extra stopping distance and get it fixed soon.
Is C0110 always a bad ABS pump?
No. Check the basics first — a weak battery, a poor high-current ground, corroded wiring, or a failed pump relay can all set C0110 with a good pump. Confirm power, ground, and relay before replacing the expensive hydraulic unit.
Why don't I hear the ABS self-test anymore?
Many vehicles briefly run the ABS pump on start-up or first drive. If the motor circuit is faulty, that buzz/whir disappears — a useful clue that the pump isn't running.