LF Wheel Speed Sensor Range/Performance
2007-2007 Mazda MX-5 Miata 2.0L I4
The 2007 Mazda MX-5 Miata is equipped with a 2.0L inline-4 engine. Below you'll find detailed c0021 diagnostic code information including labor time estimates, cost ranges, and technician notes specific to this engine configuration.
Description
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.
Related Codes
Other Chassis Codes
- C0022RF Wheel Speed Sensor Range/Performance
- C0023LR Wheel Speed Sensor Range/Performance
- C0024RR Wheel Speed Sensor Range/Performance
- C0025LF Wheel Speed Sensor Circuit Intermittent
- C0026RF Wheel Speed Sensor Circuit Intermittent
- C0027LR Wheel Speed Sensor Circuit Intermittent
- C0028RR Wheel Speed Sensor Circuit Intermittent
- C0035Left Front Wheel Speed Sensor Circuit
- C0036Left Front Wheel Speed Signal Erratic
- C0040Right Front Wheel Speed Sensor Circuit
C0021 on Other Vehicles
Common Questions
What does code C0021 mean on a 2007-2007 Mazda MX-5 Miata?
C0021 stands for "LF Wheel Speed Sensor Range/Performance". The left front wheel speed sensor output is outside the expected range under current driving conditions.
What are the symptoms of C0021 on a Mazda MX-5 Miata?
Common symptoms of C0021 include: ABS warning light on, Traction control light on, Speedometer fluctuation, ABS activating at inappropriate times.
What causes C0021 on a 2007-2007 Mazda MX-5 Miata?
Common causes of C0021 include: Wheel speed sensor air gap too large, Tone ring corrosion or damage, Sensor magnet weakened, Wheel bearing excessive play.
Last updated: March 2026