Easy one-page printout for the garage or repair shop
This summary uses the existing diagnostic information shown in full below.
This code means that the car's computer is having trouble understanding the speed of the right rear wheel. It's like when you can't tell how fast a toy car is moving because the wheels are spinning too fast or too slow.
The car's computer monitors the speed of each wheel to ensure proper functioning of systems like ABS. If the speed of the right rear wheel doesn't match expected values, this code is triggered.
The C066B code indicates a correlation issue with the right rear wheel speed sensor B. The sensor sends signals to the vehicle's control module, which compares the speed of all wheels. A discrepancy in the expected speed readings from the right rear wheel triggers this code.
• ABS warning light on
• Traction control light on
• Inconsistent braking performance
• Faulty wheel speed sensor
• Damaged wiring or connectors
• Malfunctioning ABS module
ABS: Anti-lock Braking System
OBD-II: On-Board Diagnostics II
• Inspect the right rear wheel speed sensor for damage.
• Check the wiring and connectors for corrosion or breaks.
• Test the ABS module for proper function.
• Replace the faulty wheel speed sensor.
• Repair or replace damaged wiring or connectors.
• Reprogram or replace the ABS module if necessary.
• OBD-II scanner
• Multimeter
• Wheel speed sensor removal tool
$100 - $300
Moderate
• Chevrolet Silverado
• GMC Sierra
• Cadillac Escalade
• Regularly inspect wheel speed sensors.
• Keep sensor areas clean and free of debris.
• Ensure proper maintenance of the ABS system.
Sensor Issue
• Do not ignore the ABS warning light.
• Get the vehicle inspected by a professional if you notice braking issues.
Check with your vehicle manufacturer for specific warranty coverage related to the ABS system and sensors.
This code has been commonly reported in vehicles with high mileage or those frequently driven in harsh conditions.
Moderate – While the vehicle may still be drivable, the ABS system may not function correctly, affecting braking safety.
Driving with a malfunctioning ABS system can be dangerous, especially in slippery conditions. It is advisable to address this issue promptly.
• Drive the vehicle at a moderate speed.
• Ensure the vehicle is on a flat surface for accurate sensor readings.
The right rear wheel speed sensor is located near the wheel hub of the right rear wheel.
Q: Can I drive with a C066B code?
A: It's possible, but not recommended. The ABS system may not work properly, which can affect your ability to stop safely.
Q: How do I reset the ABS light?
A: After fixing the issue, the ABS light can be reset using an OBD-II scanner. If the problem persists, the light will come back on.
Pro · Four-system diagnostics
A handheld scanner aimed at engine, transmission, ABS, and airbag diagnostic work.
Chassis and ABS faults usually need a scanner that can read brake-system data directly.
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Universal · Torque wrench
Useful when reassembly torque matters for wheel, suspension, and under-hood fasteners.
Useful when wheel, hub, or suspension hardware needs correct reassembly torque.
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Universal · Drive-on ramps
Helpful for safer access underneath the vehicle during exhaust, EVAP, and underbody inspection work.
Helpful for safer access during underbody inspection work.
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