Chassis, generic

C066C Right Rear Wheel Speed Sensor B Incorrect Component Installed

Check engine lightUsually off
EmissionsNot relevant
Drive cycleRequired
Limp modePossible

C066C indicates that the part on the second right rear speed channel differs from the one the module is set up for. No carmaker documents the code or its detection logic. Parts for the rear hub come in several versions: Schaeffler lists wheel bearings both with a multipole encoder and without one, plus third-generation units with the sensors built in, so a hub from the wrong range may lack the encoder or the second sensor altogether. Orientation matters too. NSK advises identifying the encoder side with a magnetic test card and fitting the bearing so that this face ends up next to the sensor; NTN-SNR suggests a paper clip for the same check. Since the code points to the part rather than to wiring, the fitted hub and sensor numbers are compared with the vehicle's specification first.

Likely causes

Hub or bearing from a variant without encoder or second sensor
Bearing fitted with the encoder side facing away from the sensor
Sensor of another type or vehicle fitted

Symptoms

  • Warning appears right after work on the right rear hub
  • Redundant or automated brake functions not available

Repair estimate

DifficultyMediumWorkshop job
Parts and labour€60–500
Time0.3–2 h

Typical range across vehicles; the real cost depends on what the testing finds.

Parts involved

rr wss btone ring

Related codes

C0666C066BC0558C0665

References: schaeffler.com, nsk.com, techtalk.ie.