Chassis, generic

C065D Right Front Wheel Speed Sensor B Correlation

Check engine lightUsually off
EmissionsNot relevant
Drive cycleRequired
Limp modePossible

C065D says the second right front speed value disagrees with its comparison partners although no circuit fault is found. What it is compared with depends on the architecture. A Knorr-Bremse patent for commercial vehicles lets a separate redundancy system read part of the wheel speeds, for instance one wheel per axle, and exchanges all values over CAN, which makes a second sensor at every wheel unnecessary; there a mismatch can also stem from the data link between two control units. Continental's sensor with two elements can either switch to the healthy element or average both, which first requires deciding whether they agree. For automated driving, Bosch Engineering adds a redundant brake unit to its integrated power brake. No carmaker publishes C065D or its tolerance.

Likely causes

Sensor B badly seated or air gap differing from sensor A
Encoder track damaged where only one element reads it
Disturbed data exchange between the brake control units

Symptoms

  • Warning for brake or driver assistance system after a drive
  • Automated driving functions refused, ABS usually unaffected

Repair estimate

DifficultyMediumWorkshop job
Parts and labour€60–900
Time0.5–3 h

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

Parts involved

rf wss brf wsstone ring

Related codes

C0659C065CC065EC050BC0656

References: patents.google.com, patents.google.com, bosch-engineering.com.