C0110 Code: Pump Motor Circuit Malfunction

Quick answer

• What the code means: The C0110 code indicates that the Antilock Brake System (ABS) module has detected a fault in the electrical circuit of the ABS pump motor.
• Severity: It is safe to drive your vehicle, but you should have it inspected as soon as possible. Your primary braking system will still function, but the ABS and traction/stability control systems will be disabled, which can be dangerous in emergency braking situations or slippery conditions.
• Most common cause: The most frequent cause of a C0110 code is a faulty ABS pump motor itself.

What the C0110 code means

The official OBD-II definition for the C0110 code is "Pump Motor Circuit Malfunction." In plain English, this means that the computer that controls your antilock brakes (the ABS module) has detected a problem with the electrical circuit that powers the ABS pump motor.

The ABS pump motor is a crucial component of your vehicle's antilock braking system. When you brake hard and the system detects a wheel locking up, the ABS module rapidly pulses the brakes on that wheel. The pump motor provides the necessary hydraulic pressure to do this. When the C0110 code is set, it means that the ABS module can no longer control the pump motor, effectively disabling the antilock braking feature.

Common symptoms

When the ABS module logs a C0110 code, you will likely notice one or more of the following symptoms:

• ABS warning light is illuminated on the dashboard
• Traction control or stability control warning light is on
• A buzzing or whirring noise may be heard from the ABS module area, even when the brakes are not being applied
• The brake pedal may feel spongy or require more effort to press
• In rare cases, the brakes may lock up during normal braking

Common causes

The causes of a C0110 code can range from simple to complex. Here are the most common causes, ranked from most to least likely:

1. Faulty ABS pump motor: This is the most common culprit. The electric motor inside the ABS pump can fail over time.
2. Blown fuse or faulty relay: The ABS pump motor is a high-current device and has its own fuse and relay. If either of these fails, the motor will not have power.
3. Wiring or connector issues: The wiring harness to the ABS pump motor can become damaged, or the connectors can become corroded or loose. This can cause a loss of power or ground to the motor.
4. Faulty ABS control module: While less common, the ABS control module itself can fail and incorrectly set a C0110 code.

How a technician diagnoses it

A qualified technician will follow a systematic process to diagnose a C0110 code. This typically involves the following steps:

1. Scan for codes: The technician will use a professional-grade OBD-II scanner to confirm the presence of the C0110 code and check for any other related codes.
2. Inspect fuses and relays: The technician will locate and inspect the fuse and relay for the ABS pump motor. If the fuse is blown, they will replace it and re-test the system.
3. Inspect wiring and connectors: The wiring harness and connectors for the ABS pump motor will be visually inspected for any signs of damage, corrosion, or loose connections.
4. Test the circuit: Using a digital multimeter, the technician will test the ABS pump motor circuit for proper voltage and ground. This will help determine if the problem is with the wiring or the motor itself. A good reading would show battery voltage at the power wire and a good ground on the ground wire. An open circuit or a short to ground would indicate a wiring problem.
5. Test the motor: If the circuit tests good, the technician may use a bi-directional scan tool to command the ABS pump motor on and off. This will confirm whether the motor is functioning correctly.
6. Test the ABS control module: If all other components test good, the technician will then suspect a faulty ABS control module. This is usually the last step in the diagnostic process, as it is the least likely cause.

Typical repair cost

The cost to repair a C0110 code can vary widely depending on the underlying cause and the make and model of your vehicle.

• Fuse or relay replacement: This is the least expensive repair, typically ranging from $10 to $50.
• Wiring repair: If the problem is a damaged wire or connector, the cost will depend on the extent of the damage. A simple repair may cost between $100 and $300.
• ABS pump motor replacement: Replacing the ABS pump motor is a more involved repair and can cost between $500 and $1500 or more, depending on the vehicle.
• ABS control module replacement: This is the most expensive repair, with costs ranging from $800 to $2000 or more.

Can I keep driving with this code?

Yes, you can technically keep driving with a C0110 code. Your regular brakes will still work, so you will be able to stop the vehicle. However, it is not recommended to drive for an extended period with this code active. Without a functioning ABS, your wheels can lock up during a panic stop, causing you to lose steering control. This can be especially dangerous in wet or icy conditions. It is best to have the vehicle inspected and repaired as soon as possible.

Related codes

Several other codes are related to the C0110 code, as they all pertain to the ABS pump motor circuit:

• C0111: Pump Motor Circuit Range/Performance
• C0112: Pump Motor Circuit Low
• C0113: Pump Motor Circuit High
• U0121: Lost Communication With Anti-Lock Brake System (ABS) Control Module

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