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DTC codes / C00xx · Brakes, steering and suspension / C0050

C0050Right Rear Wheel Speed Sensor Circuit Malfunction

C0050 means the antilock brake system (ABS) control module has detected an electrical fault in the right rear wheel speed sensor circuit, such as an open, short, or implausible signal. The module compares the right rear signal with the other three wheel sensors and sets this code when the circuit does not behave as expected.

SystemChassis
Code typeGeneric (all makes)
SeverityMedium
Fix difficultyIntermediate
AreaBrakes, steering and suspension

Symptoms you may notice

  • The ABS warning light stays illuminated on the dashboard.
  • The traction control and stability control warning lights may also come on because those systems rely on the same wheel speed signal.
  • The ABS may deactivate, allowing wheel lockup during hard braking on slippery surfaces.
  • A scan tool may show an erratic or zero right rear wheel speed reading while the other three sensors read normally.
  • Often no symptoms besides the warning light, with normal brake pedal feel and ordinary driving behavior.
  • On some vehicles, the speedometer or cruise control may act erratically if the module uses that wheel signal for vehicle speed.

Common causes, most likely first

  1. Damaged or corroded wiring harness or connector at the right rear wheel speed sensor.
  2. Failed right rear wheel speed sensor itself, often due to heat, debris, or moisture intrusion.
  3. Debris, metal shavings, or rust buildup on the sensor tip or tone ring, disrupting the magnetic signal.
  4. Cracked or missing tone ring (reluctor ring) on the right rear hub or axle.
  5. Excessive wheel bearing play or hub runout altering the sensor-to-ring air gap.
  6. Open or shorted circuit in the sensor wiring between the wheel and the ABS module.
  7. Internal fault in the ABS control module, though this is less common than sensor or wiring problems.

How to diagnose and fix it

  1. Inspect the right rear sensor connector and wiring for corrosion, chafing, or loose pins, and clean or repair as needed.
  2. Remove the sensor and check the tip and tone ring for metal debris, rust, or damage; clean the mounting surface and reinstall.
  3. Measure the sensor resistance and compare it with the manufacturer's specification, and check for an open or short in the harness.
  4. Perform a live data scan of all four wheel speed sensors while rotating the right rear wheel by hand to confirm an erratic or missing signal.
  5. Check the tone ring for cracks, missing teeth, or excessive runout, and inspect the wheel bearing for play.
  6. If the sensor and wiring test good, substitute a known-good sensor or perform a wiggle test on the harness while watching live data.
  7. Clear the code and verify the repair with a road test, confirming the ABS light stays off and all wheel speeds match.

What a right rear speed sensor code really means

  • A common misdiagnosis is replacing the sensor when the real problem is a corroded connector or a chafed wire near the rear suspension, so always inspect the harness before condemning the sensor.
  • Metal debris or rust on the sensor tip or tone ring can mimic a failed sensor, and a simple cleaning often resolves the code without any parts replacement.
  • A worn right rear wheel bearing can set this code because excessive play changes the air gap between the sensor and tone ring, even when the sensor itself is healthy.
  • This code does not always mean the ABS is completely disabled; some systems retain partial function, but the warning light will stay on until the fault is repaired.
  • Related codes such as C0045 or C0055 may appear alongside C0050 if the fault affects shared wiring or the ABS module's ability to process multiple wheel signals.

Can I keep driving with C0050?

The vehicle remains driveable with normal braking in most conditions, but the ABS and stability control may be inactive, so avoid hard braking on wet, icy, or loose surfaces and get the fault diagnosed promptly. If the brake pedal feels abnormal or other brake warning lights appear, stop driving and have the vehicle inspected.

Tools that help

Tools we recommend are in the Auto Veteran shop on Amazon. As an Amazon Associate we earn from qualifying purchases.

Guidance is general and written for all OBD-II vehicles. Exact tests and values vary by model, so confirm the fault before replacing parts.

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