C0110 Code – ABS Pump Motor Circuit Malfunction

The C0110 diagnostic trouble code (DTC) is a chassis-related fault that commonly indicates a problem with the ABS Pump Motor Circuit. In many vehicles, this code is stored when the Anti-lock Braking System (ABS) control module detects an electrical or mechanical fault that prevents the ABS pump motor from operating correctly. However, the exact definition may vary slightly depending on the vehicle manufacturer, so factory service information should always be consulted for the specific model.

The ABS pump motor is an essential part of the braking system. During hard braking, it restores hydraulic pressure after the ABS module rapidly releases brake pressure to prevent wheel lock-up. Without a properly functioning pump motor, the ABS system cannot perform as designed, reducing braking stability in emergency situations.

How the ABS Pump Motor Works

When the ABS control module detects that one or more wheels are beginning to lock during braking, it activates hydraulic valves to reduce brake pressure. At the same time, the ABS pump motor restores hydraulic pressure so the braking cycle can continue multiple times per second. This process allows the driver to maintain steering control while braking.

Common Symptoms of C0110

• ABS warning light is illuminated.
• Traction Control (TCS) warning light may appear.
• Electronic Stability Control (ESC) warning light may turn on.
• ABS system becomes disabled.
• Reduced braking performance on slippery roads.
• Additional ABS-related diagnostic trouble codes may be stored.

Common Causes of C0110

• Faulty ABS pump motor.
• Blown ABS pump motor fuse.
• Defective ABS pump relay.
• Damaged or corroded wiring.
• Loose electrical connectors.
• Low battery voltage.
• Poor ground connection.
• Internal ABS control module failure.

Diagnosis

A technician should first scan the ABS module for stored trouble codes and inspect freeze frame data if available. The next step is checking battery voltage because low voltage may trigger ABS-related faults. The ABS pump motor fuse and relay should be inspected before testing the wiring harness for open circuits, shorts, or corrosion. If the electrical circuit is functioning correctly, the pump motor can be activated using a professional scan tool to verify proper operation. Finally, the ABS control module should be inspected if all other components pass testing.