ABS and brakes

C0041 — Right Front Wheel Speed Sensor Signal Out of Range

Severity: medium Drive with care, to a shop

What C0041 means

The ABS control module compares the signals from all four wheel speed sensors. The right front sensor signal was erratic, dropping out, or did not match the other wheels. Normally the sensor reads a toothed tone ring on the hub and sends a pulse frequency to the module. When the data can't be trusted, the system disables ABS and traction control.

Symptoms

  • ABS warning light on
  • Traction or stability control warning light on
  • ABS doesn't activate in a hard stop
  • Speedometer jumps or reads wrong on some vehicles
  • Fault comes and goes, often at speed or over bumps

Possible causes

  1. Failed right front wheel speed sensor
  2. Damaged wiring or connector at the knuckle (chafed, broken, corroded)
  3. Damaged or dirty tone ring, or metal debris stuck to the sensor
  4. Excess sensor air gap from a worn hub bearing or a poorly seated sensor
  5. Mismatched tire sizes or one badly worn tire
  6. Faulty ABS module (rare)

How to diagnose

  1. Scan for codes and note any other wheel speed or ABS codes
  2. View live data and compare the right front wheel speed with the other three while driving
  3. Inspect the sensor, its mounting, the harness and connector for damage, moisture and corrosion
  4. Wiggle the harness with the scan tool running; a signal dropout points to a broken wire or poor contact
  5. Remove the sensor, clean off dirt and debris, and check the tone ring for cracks, rust and damaged teeth
  6. Check hub bearing play and sensor seating and air gap
  7. Measure sensor resistance and wiring continuity to the module per the factory manual
  8. Check tire sizes and wear

Common fixes

  • Clean the sensor and tone ring and reseat the sensor
  • Replace the right front wheel speed sensor
  • Repair the wiring or replace the connector
  • Replace the tone ring or the hub and bearing assembly
  • Match tires in size and wear
  • Repair or replace the ABS module only after ruling out everything else

Questions and answers

Can I drive with a C0041 code?

Yes, but carefully and not for long. The base brakes work, but ABS and traction control are off, so stopping distance and control suffer on wet or slippery roads.

How do I tell a bad sensor from bad wiring?

Watch the wheel speed in live data while wiggling the harness. If the signal drops out when the wires move, suspect the wiring or connector. If the harness is fine and the signal is still erratic, check the sensor and tone ring.

Why does the code come and go?

Common causes are a poor connector contact, a cracked wire, or dirt on the sensor or ring. The signal gets worse with vibration, moisture or heat, so the fault can be intermittent.

This is general information about the code. The meaning can differ between makes and models: a scan tool and the repair manual for your car will show the exact cause.