C0021moderate severityChassis

LF Wheel Speed Sensor Range/Performance

on 2014 Ram 2500 6.7L I6 Cummins Diesel · 4WD

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

  1. Compare all four wheel speed sensor readings at steady speed
  2. Inspect sensor air gap with feeler gauge
  3. Check tone ring for missing teeth or rust
  4. Inspect wheel bearing for play
  5. Scope sensor output waveform

Repair notes

Adjust sensor air gap or replace sensor. Inspect tone ring for damage.

Other Chassis codes on this vehicle

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