What does code C0665 mean?

DTC codes / C06xx · Brakes, steering and suspension / C0665

C0665Left Rear Wheel Speed Sensor B Incorrect Component Installed

This code means the antilock brake system (ABS) module has detected that the left rear wheel speed sensor circuit is receiving a signal from a sensor that does not match the expected part for that position. The module compares the sensor's electrical signature and signal pattern against its stored calibration and flags the mismatch as an incorrect component installed.

SystemChassis

Code typeGeneric (all makes)

SeverityMedium

Fix difficultyIntermediate

AreaBrakes, steering and suspension

Guidance is general and written for all OBD-II vehicles. Exact tests and values vary by model, so confirm the fault before replacing parts.