OBD-II code · Chassis
C0033 Left Front Wheel Speed Sensor Signal Erratic
The control module sees erratic pulses from the left front wheel speed sensor at speed. Common cause is metallic debris on a magnetic encoder or a damaged tone ring.
Is it safe to drive with C0033?
Usually safe to drive in the short term. Get it diagnosed when convenient, sooner if the car drives differently.
Common causes
- Most likelyMagnetic encoder ring contaminated
- PossibleTone ring cracked or missing teeth
- Less likelyConnector with intermittent contact under vibration
Symptoms
- ABS warning light on
- ESC/stability control deactivated
- Possible reduced brake assist
- Speedometer may behave erratically
Repair at a glance
- Difficulty
- Medium
- DIY friendly
- Often, with basic tools
- Typical labour
- 0.5–2.5 h
- Emissions test
- Usually unaffected
- Parts involved
- Wheel Speed Sensor Fl, Tone Ring, Hub Bearing
Related codes
- C0030Left Front Wheel Speed Sensor Circuit Range/Performance
- C0031Left Front Wheel Speed Sensor Circuit Low
- C0032Left Front Wheel Speed Sensor Circuit High
- C0034Left Front Wheel Speed Sensor No Signal
- C0035Left Front Wheel Speed Sensor Circuit Malfunction
- C0036Left Front Wheel Speed Sensor Circuit Intermittent
Code data: OBDex open dataset (CC0). Labour times are typical ranges, not a quote.