ezOBD2 - Free OBD2 Code Lookup and Check Engine Light Diagnostic Tool

Diagnose Your Check Engine Light

Enter OBDII code below:

Code C0660

Symptoms

• ABS warning light on

• Traction control warning light on

• Inconsistent speedometer readings

Common Causes

• Faulty wheel speed sensor

• Damaged wiring or connectors

• Malfunctioning ABS module

Glossary

ABS: Anti-lock Braking System

OBD-II: On-Board Diagnostics II

Related Codes

• C0655

• C0665

Laymans terms

The car's computer is having trouble reading the speed of the left back wheel. It's like when your bicycle speedometer isn't working right and you can't tell how fast you're going.

Explanation

The vehicle's control module has detected an issue with the signal from the left rear wheel speed sensor, which is not within the expected range.

Technical description

The C0660 code indicates that the signal from the left rear wheel speed sensor B is not performing within the expected parameters. This sensor is responsible for sending data about the wheel's speed to the vehicle's control module, which uses this information for functions like ABS and traction control.

Diagnosis steps

• Perform a visual inspection of the wheel speed sensor and wiring.

• Use a multimeter to check the sensor's electrical resistance.

• Scan the vehicle with an OBD-II scanner to confirm the code.

Repair procedures

• Replace the faulty wheel speed sensor.

• Repair or replace damaged wiring or connectors.

• Replace the ABS module if necessary.

Tools required

• OBD-II scanner

• Multimeter

• Socket set

Estimated repair cost

$150 - $400

Difficulty level

Moderate

Commonly affected vehicles

• Chevrolet Tahoe

• GMC Yukon

• Cadillac Escalade

Preventive measures

• Regularly inspect the wheel speed sensors.

• Ensure wiring and connectors are intact.

• Avoid driving through deep water.

Error code type

Sensor Issue

User experience recommendations

• Do not ignore the ABS warning light.

• Have the vehicle inspected by a professional if unsure.

• Avoid harsh driving conditions until repaired.

Warranty information

Check with your vehicle manufacturer for specific warranty coverage on ABS components.

Historical data

This code has been associated with issues in vehicles with ABS systems dating back to the early 2000s.

Urgency level

Moderate – While the vehicle may still be drivable, ABS and traction control functions may be compromised.

Legal and safety notice

Driving with a faulty wheel speed sensor can affect braking performance and vehicle stability. It is recommended to address this issue promptly.

Testing conditions

• Vehicle stationary

• Ignition on, engine off

Component location

The left rear wheel speed sensor is located near the brake assembly of the left rear wheel.

FAQs

Q: Can I drive my car with the C0660 code?
A: While you can drive the car, it's not recommended as the ABS and traction control systems may not function properly.

Q: How can I reset the ABS warning light?
A: The light can be reset by fixing the underlying issue and using an OBD-II scanner to clear the code.

Last updated: Jun 8, 2026 • Source: internal database
🌙