C0245
Wheel Speed Sensor Frequency Mismatch
The ABS control module has detected that the frequency of one wheel speed sensor signal does not match the others under stable driving conditions. This often indicates a tone ring with extra or missing teeth or a sensor with degraded signal quality.
- Check engine light: Not always
- Emissions related: No
- Repair difficulty: medium
Symptoms
- ABS warning light on
- ESC/stability control deactivated
- Possible reduced brake assist
- Speedometer may behave erratically
Common causes
Ordered by how often each turns out to be the cause.
- Tone ring damaged or contaminatedCommon
- Wheel speed sensor degradedPossible
- Tyre size mismatchLess likely
Parts involved
- Wheel Speed Sensor
- Tone Ring
- ABS Control Module
C0245 is a generic OBD-II code defined by SAE J2012. Exact wording and diagnostic procedure vary by manufacturer and model. Code definitions are drawn from the public-domain OBDex dataset; the workshop notes are our own.