OBD-II code · Chassis

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.

Is it safe to drive with C0666?

The car may go into limp mode (reduced power). Get it diagnosed before a long trip.

Common causes

  • Most likelySensor wiring broken
  • Less likelyPin pushed back out of connector body
  • Less likelyCracked solder joint inside the module or sensor

Symptoms

  • ABS warning light on
  • ESC/stability control deactivated
  • Possible reduced brake assist
  • Speedometer may behave erratically

Repair at a glance

Difficulty
Medium
DIY friendly
Often, with basic tools
Typical labour
0.5–2 h
Emissions test
Usually unaffected
Parts involved
Rr Wss B

Code data: OBDex open dataset (CC0). Labour times are typical ranges, not a quote.