C0045
Left Rear Wheel Speed Sensor Circuit Malfunction
The ABS control module has detected a fault in the left rear wheel speed sensor circuit. Loss of wheel speed information disables ABS and stability control, and a separate ABS warning lamp is illuminated.
- 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.
- Wheel speed sensor failedCommon
- Tone ring damaged or contaminatedPossible
- Wiring break or chafe under chassisPossible
- Wheel hub bearing with integrated sensor ring failedLess likely
Parts involved
- Wheel Speed Sensor
- ABS Control Module
- Tone Ring
- Sensor Wiring
C0045 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.