C0021moderate severityChassis
LF Wheel Speed Sensor Range/Performance
on 2020 Tesla Model 3 Standard Range Plus Single Motor RWD · AWD
What this code means
The left front wheel speed sensor output is outside the expected range under current driving conditions.
Symptoms
- ABS warning light on
- Traction control light on
- Speedometer fluctuation
- ABS activating at inappropriate times
Common causes
- Wheel speed sensor air gap too large
- Tone ring corrosion or damage
- Sensor magnet weakened
- Wheel bearing excessive play
Diagnostic steps
- Compare all four wheel speed sensor readings at steady speed
- Inspect sensor air gap with feeler gauge
- Check tone ring for missing teeth or rust
- Inspect wheel bearing for play
- Scope sensor output waveform
Repair notes
Adjust sensor air gap or replace sensor. Inspect tone ring for damage.
Other Chassis codes on this vehicle
C0022
RF Wheel Speed Sensor Range/Performance
C0023
LR Wheel Speed Sensor Range/Performance
C0024
RR Wheel Speed Sensor Range/Performance
C0025
LF Wheel Speed Sensor Circuit Intermittent
C0026
RF Wheel Speed Sensor Circuit Intermittent
C0027
LR Wheel Speed Sensor Circuit Intermittent
C0028
RR Wheel Speed Sensor Circuit Intermittent
C0035
Left Front Wheel Speed Sensor Circuit
C0036
Left Front Wheel Speed Signal Erratic
C0040
Right Front Wheel Speed Sensor Circuit