OBD-II code · Chassis

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.

Is it safe to drive with C0238?

Usually safe to drive in the short term. Get it diagnosed when convenient, sooner if the car drives differently.

Common causes

  • Most likelyTyre sizes or wear levels do not match across axles
  • PossibleTone ring missing teeth on one wheel
  • Less likelyWheel speed sensor degraded

Symptoms

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

Repair at a glance

Difficulty
Medium
DIY friendly
Often, with basic tools
Typical labour
0.5–3 h
Emissions test
Usually unaffected
Parts involved
Wheel Speed Sensor, Tone Ring, Tires, ABS Control Module

Code data: OBDex open dataset (CC0). Labour times are typical ranges, not a quote.