C0031
Left Front Wheel Speed Sensor Circuit Low
Voltage on the left front wheel speed sensor circuit is below the expected range. The fault is typically caused by a short to ground or an open in the supply line.
- 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.
- Sensor wiring shorted to groundCommon
- Sensor coil open internallyPossible
- Connector pins corroded - high contact resistanceLess likely
Parts involved
- Wheel Speed Sensor Fl
- Sensor Wiring
- ABS Control Module
C0031 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.