OBD-II reference

All 9.533 generic OBD-II codes, explained in detail.

Causes, inspection steps and sources — a comprehensive DIY archive. Created and maintained with love for the detail. Good luck and have fun!

Chassis generic / SAE

C0238

Speed Wheel-to-Wheel Mismatch

The ABS control module has detected an implausible speed difference between wheels that cannot be explained by cornering. This typically points to one suspect sensor, mismatched tyre sizes or a damaged tone ring.

SystemChassis
Typegeneric / SAE
GroupC0
Range / number2 / 38

Possible causes

  • Tyre sizes or wear levels do not match across axles high
  • Tone ring missing teeth on one wheel medium
  • Wheel speed sensor degraded low

Symptoms

  • ABS warning light on
  • ESC/stability control deactivated
  • Possible reduced brake assist
  • Speedometer may behave erratically

Inspection / repair

  • Difficulty: medium
  • DIY: possible
  • Estimated cost: 80–600 €
  • Estimated time: 0.5–3 h
  • Component: wheel speed sensor
  • Component: tone ring
  • Component: tires
  • Component: abs control module

Sources

References

How to read OBD-II codes

The first letter names the vehicle system, the second digit distinguishes generic from manufacturer-specific, the remaining digits group fault area and number.

PPowertrain: engine, transmission, emissions
BBody: chassis trim, comfort, interior
CChassis: suspension, brakes, steering
UNetwork: CAN, control modules, communication