C066C code meaning
Right Rear Wheel Speed Sensor B Incorrect Component Installed
What C066C means
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.
C066C at a glance
- Check engine lightUsually not
- Emissions testNot an emissions code
- Limp modePossible
- Repair difficultyMedium
- Typical labor0.3 to 2 hours
- Clears after repairAfter a drive cycle
Symptoms of C066C
- Warning appears right after work on the right rear hub
- Redundant or automated brake functions not available
Common causes of C066C
- Most likelyHub or bearing from a variant without encoder or second sensor
- PossibleBearing fitted with the encoder side facing away from the sensor
- PossibleSensor of another type or vehicle fitted
Check the most likely causes first. Replacing parts by guesswork is the most expensive way to clear a code.
Parts involved
Rr wss bTone ring
What each part of C066C means
| C | Chassis system: brakes, ABS, steering and suspension. |
| 0 | Generic code: it means the same on every make (SAE standard). |
| 6C | The exact fault in that area. |
What to do next
- Note C066C and any other codes stored with it: several codes together often point to one cause.
- Check for loose connectors and damaged wiring around the parts the code names.
- Check open recalls for your car: some faults are fixed for free by the dealer. Enter your VIN.
- Clear the code only after the repair. If it comes back, the fault is still there.
Buying a used car? Scan it for stored codes before you pay. A recently cleared memory can hide a problem.
Questions about C066C
What does C066C mean?
C066C means "Right Rear Wheel Speed Sensor B Incorrect Component Installed". C066C indicates that the part on the second right rear speed channel differs from the one the module is set up for. It is a generic code, so it means the same on every make.
Is it safe to drive with C066C?
Drive gently and only to a workshop. With C066C the car can go into limp mode (reduced power) to protect itself.
Will C066C fail an emissions test?
C066C is not an emissions code, so on its own it usually does not fail an emissions test. Other stored codes or a lit check engine light still can.
How hard is C066C to fix?
Difficulty: medium. A typical repair takes 0.3 to 2 hours of work. This is a job for a workshop.
Will C066C clear itself after the repair?
After the repair the car has to complete a drive cycle (a mix of city and highway driving) before the test runs again. Until then the readiness monitor shows "not ready", which can fail an inspection.