C0234
Wheel Speed Sensor Frequency Error
The ABS control module has detected that one of the wheel speed sensor signals has a frequency outside the plausible range, e.g. unrealistically high pulses or signal dropouts at speed. Stability control may be limited.
- 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, missing teeth, or contaminatedCommon
- Sensor air gap incorrect (loose mounting)Possible
- Wheel speed sensor degradedLess likely
Parts involved
- Wheel Speed Sensor
- Tone Ring
- ABS Control Module
C0234 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.