Chassis, generic

C003C Rear Tone Wheel

Check engine lightUsually off
EmissionsNot relevant
Drive cycleNot required
Limp modePossible

Covers a single rear tone wheel (reluctor or encoder ring) on vehicles that use one combined rear wheel speed signal, for example from a differential or rear axle sensor, rather than separate left and right rear rings. It is a signal-plausibility code set when the module sees an erratic, noisy or intermittent rear speed signal consistent with a damaged, contaminated or loose tone ring rather than a sensor circuit failure. A fault disables ABS, traction and stability control and lights the ABS warning lamp while base braking remains; on such vehicles rear-based functions like electronic brake-force distribution are affected. No manufacturer documents this code publicly; NHTSA's EPS safety report lists the rear tone wheel code C003C among the J2012 wheel speed codes.

Likely causes

Damaged or contaminated tone ring
Loose or displaced bearing or axle ring
Excessive sensor-to-ring air gap

Symptoms

  • ABS warning lamp on
  • ABS and stability control disabled
  • Intermittent rear speed signal

Repair estimate

DifficultyMediumWorkshop job
Parts and labour€100–700
Time0.8–2.5 h

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

Parts involved

rear tone wheel

Related codes

C003DC003EC0036

References: rosap.ntl.bts.gov, rosap.ntl.bts.gov, en.wikipedia.org.