Right Rear Wheel Speed Sensor B Intermittent/Erratic: the signal is intermittent or erratic. Wheel-speed signals feed ABS, ESC, traction control and the speedometer.
High severity. Can I keep driving?The regular brakes usually keep working, but without ABS or the driver aids. Drive very carefully and go to a repair shop; if the pedal feel changes, do not keep driving.
Symptoms
- ABS warning light on
- ESC/stability control deactivated
- Possible reduced brake assist
- Speedometer may behave erratically
Most likely causes
- Connector loose or oxidized
- Connector with intermittent contact under vibration
- Harness routed against vibrating component
What to check, in order
Start with the simplest. You can tick off each step.
Good to know
- Repair difficulty: medium
- It can trigger limp mode.
What each character of C066A means
- C: Chassis
- 0: Generic code: same on every make
- 6: Subsystem depends on the code range
- 6A: Specific fault in that system
Frequently asked questions
Can I keep driving with code C066A?
The regular brakes usually keep working, but without ABS or the driver aids. Drive very carefully and go to a repair shop; if the pedal feel changes, do not keep driving.
What causes code C066A?
The most common causes are: connector loose or oxidized; connector with intermittent contact under vibration; harness routed against vibrating component.
Related codes
Sources
Values and procedures vary by manufacturer. If it affects brakes, steering, fuel or high voltage, see a professional. Updated: 2026-11-04. How we build these pages.