OBD-II trouble code
C0050: Right Rear Wheel Speed Sensor Circuit
The ABS module detected a fault in the right rear wheel speed sensor or its circuit. The ABS and traction/stability lights typically come on and those systems are disabled, but normal (base) braking still works.
Quick facts
- System
- Chassis
- Category
- ABS / Wheel Speed
- Severity
- Medium severity
- Drivable
- Usually safe to drive short-term
- Repair cost range
- $100 – $700
- DIY difficulty
- Intermediate DIY
What does C0050 mean?
Every wheel has a speed sensor that reports how fast that wheel is turning to the anti-lock brake system (ABS) module. The module compares all four wheel speeds to catch a wheel that is about to lock under braking (ABS), a wheel that is spinning (traction control), or a vehicle that is starting to slide (stability control). C0050 sets when the module sees a problem in the right rear wheel speed sensor circuit — the signal is missing, out of range, erratic, or electrically open or shorted — so it can no longer trust that corner's speed reading.
Because the safety systems need a dependable signal from every wheel, losing one input causes the module to switch off ABS, traction control, and stability control and light the matching dash warnings. Your ordinary hydraulic brakes are not affected — the vehicle still stops normally — but the anti-lock and traction/stability functions that help during a hard stop or on slippery roads stay disabled until the fault is repaired.
C0050 completes the four-corner wheel-speed set alongside C0035 (left front), C0040 (right front), and C0045 (left rear). A very common, often-overlooked cause on GM vehicles (documented in a GM technical service bulletin) is metallic debris collecting on the wheel bearing's magnetic encoder ring, which produces an erratic signal and can frequently be cleaned rather than replaced. The rear sensor wiring also runs along the underbody and over the rear axle, where it is exposed to road spray, salt, and chafing. Note that C0050 is the SAE-generic designation for the right rear wheel speed sensor circuit; some manufacturers — GM in particular — assign wheel-speed faults to different C-code numbers or add a sub-code, so confirm the exact definition in service data for your specific vehicle before replacing parts.
Common causes
- Failed right rear wheel speed sensor
- Metallic debris on the wheel bearing's magnetic encoder ring (often cleanable)
- Corroded, broken, or loose connector at the sensor
- Chafed or open wiring where the rear harness runs over the axle
- Damaged, cracked, or contaminated tone/reluctor ring
- Worn wheel hub/bearing with excessive play (integrated sensor designs)
- ABS module fault (less common)
Symptoms
- ABS warning light on
- Traction control and stability control (ESC) warning lights on
- ABS, traction, and stability features disabled
- Normal (base) braking still works
- Right rear wheel speed reads 0 mph or jumps erratically on a scan tool
Diagnostic steps
- 1.Scan the ABS module and record all C-codes and any sub-codes to confirm the wheel and the fault type (open, shorted, erratic).
- 2.Graph all four wheel-speed live-data values while driving slowly above 10 mph; a right rear reading of 0 mph or erratic spikes confirms the affected corner.
- 3.Inspect the right rear sensor, connector, and wiring for corrosion, damage, or a loose connection, paying attention to where the harness crosses the axle.
- 4.Remove the sensor and inspect the magnetic encoder/tone ring for metallic debris, rust, cracks, or missing teeth; clean debris before condemning parts.
- 5.Measure the sensor's resistance or output and verify the air gap and that there is no hub-bearing play.
- 6.Repair or replace the sensor or wiring, clear the codes, and road-test to confirm all four wheel-speed signals track correctly.
Repair cost
$100 – $700
A wheel speed sensor is a common, moderate-cost repair: parts often run $30-$150 with about an hour of labor, so many C0050 repairs land around $100-$300. Cleaning debris off the encoder ring can cost little to nothing. If the sensor is integrated into the wheel hub/bearing assembly, replacing the hub raises the total toward $400-$700. Inspect and clean before buying parts.
Estimate your repair
Run the numbers for your vehicle
Open the Repair Cost Estimator with wheel speed sensor replacement preselected. Adjust labor rate and vehicle category to fit your situation.
DIY vs shop
This is an intermediate DIY job. It usually involves diagnostic steps, specialty parts, and some careful work in tight spaces. If you have the tools and a service manual or trustworthy video for your specific vehicle, it is achievable in a weekend. Otherwise, a competent independent shop will be faster.