C0035Chassis
Chassis / ABS
Left Front Wheel Speed Sensor — Circuit
Meaning
The ABS module detects a problem in the left front wheel speed sensor circuit. Without a reliable signal from that wheel, ABS and ESP cannot operate correctly.
Common causes
- Faulty wheel speed sensor
- Dirty or damaged tone ring (toothed ring)
- Broken or chafed sensor wiring
- Corroded or water-ingressed connector
- Wrong air gap between sensor and tone ring
Symptoms
- ABS and ESP lights on
- ABS and stability control disabled
- Possibly inaccurate speedometer
- Emergency brake assist unavailable
Severity
Moderate/serious: basic braking remains, but disabled ABS/ESP reduces safety; check as soon as possible.
What to do
- Read live wheel speeds and compare across the four wheels
- Inspect the sensor, tone ring and air gap
- Check the sensor wiring and connector (water/corrosion)
- Replace the sensor if the signal is missing with an intact tone ring