C0035
Left Front Wheel Speed Sensor Circuit
Moderate· Fix soonDIY friendlyChassisManufacturer: GM (Chevrolet, GMC, Buick, Cadillac)
What it means
On GM vehicles this code means the ABS module has a problem with the left front wheel speed sensor. The sensor tells the ABS module how fast that wheel is turning. On other makes, check what this code means for your brand.
Is it safe to drive?
Normal brakes still work, but ABS, traction control and stability control are switched off. Leave more stopping distance, especially in the wet.
Symptoms
- ABS and traction control lights on
- Speedometer erratic on some vehicles
- ABS activating at low speed
Probable causes
Most likely first
- 1Damaged sensor wire (it runs near the suspension and gets stretched or cut)
- 2Corroded connector
- 3Rust lifting the sensor or a cracked tone ring
- 4Failed sensor
- 5Worn wheel bearing (on hubs with built-in sensors)
How to diagnose it
Work through these in order before buying parts
- 1Record the code and its freeze frame data (speed, load, temperature when it set), then clear it and see if it comes back.
- 2Compare all four wheel speeds on live data while driving slowly. The faulty one will read zero or drop out.
- 3Inspect the wire from the sensor to the body for damage.
- 4Measure sensor resistance (passive sensors) or check power and signal (active sensors).
- 5Check for technical service bulletins (TSBs) or software updates for your make and model; some codes have known factory fixes.
Common fixes
- Repair the wiring
- Replace the wheel speed sensor
- Replace the hub bearing assembly if the sensor is built in
- Clean rust from the sensor mount
This information is general guidance for the listed makes. Exact causes, specifications and procedures vary by vehicle, so confirm with your service manual or a qualified mechanic before replacing parts.