C0666
Right Rear Wheel Speed Sensor B Circuit/Open
Right Rear Wheel Speed Sensor B Circuit/Open: the circuit is open. Wheel-speed signals feed ABS, ESC, traction control and the speedometer.
Right Rear Wheel Speed Sensor B Circuit/Open: the circuit is open. Wheel-speed signals feed ABS, ESC, traction control and the speedometer.
Common causes
- high
Sensor wiring broken
One of the most commonly reported causes for this code — check this first.
Typical part cost: $90-550
- low
Pin pushed back out of connector body
Less common, but worth ruling out after the more likely causes.
Typical part cost: $90-550
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First things to check
- 1Confirm the code with a scan tool and check for additional related codes.
- 2Inspect the relevant sensors, wiring, and connectors for damage or corrosion.
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Related codes
See related trouble codes
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Frequently asked questions
What does C0666 mean?
C0666 means "Right Rear Wheel Speed Sensor B Circuit/Open". It is a generic OBD-II code that points to a fault in the chassis.
What are the most common causes of C0666?
sensor wiring broken; pin pushed back out of connector body; cracked solder joint inside the module or sensor — these are the most commonly reported causes. Verify with a proper diagnosis before replacing parts, or use the Wrenchify app for a vehicle-specific diagnosis.
Can I keep driving with this code?
This code can put the vehicle into limp or reduced-power mode. Avoid extended driving and have the vehicle diagnosed promptly. Use the Wrenchify app for a full diagnosis specific to your vehicle.
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