C0050 on 2013-2017 Chevrolet Express: Right Rear Wheel Speed Sensor Fixes

What's Unique About the 2013-2017 Chevrolet EXPRESS

On the Chevrolet Express and its platform-mate, the GMC Savana, this code is frequently caused by wiring issues, not just a failed sensor. GM has issued technical service bulletins specifically pointing to problems where the sensor wires are pulled out of their terminal crimps at the connector, often due to improper harness routing around the rear brake hose. Another common failure point is internal corrosion within the wiring harness a few inches or feet from the sensor, which can be difficult to spot visually but can be found with a multimeter.

Diagnostic Flowchart

Tap your situation to follow the diagnostic path that matches what you're seeing on this vehicle.

Symptoms You May Notice

• ABS warning light is on.
• StabiliTrak warning light is on. [Bulletin #18316]
• Traction Control warning light is on. [Bulletin #18316]
• "Service Stabilitrak" or "Service Traction Control" message on the Driver Information Center. [Bulletin #18316, 6]
• In rare cases with related electrical faults, a "Reduced Engine Power" message may appear.

Most Likely Causes

1. Damaged or Corroded Wheel Speed Sensor Wiring/Connector 🔴 High Probability → Shop ABS Wheel Speed Sensor A manufacturer TSB confirms that the harness can be routed incorrectly, causing it to pull tight and damage the wires or terminals at the connector during normal suspension movement. The rear axle location also exposes the wiring to road salt and moisture, leading to internal wire corrosion that may not be visible from the outside.
   How to confirm: Visually inspect the wiring harness from the sensor to the main frame rail. Pay close attention to the connector at the sensor for pulled wires, corrosion, or loose terminals. Check that the harness is not wrapped around the brake hose. If no visible damage is found, use a multimeter to check for continuity and resistance between the sensor connector and the EBCM connector. High or fluctuating resistance when wiggling the harness indicates an internal break.
   Typical fix: Repair the damaged section of wire or replace the sensor connector pigtail. 🎬 Watch: A real-world diagnosis and repair of the C0050 code. In cases of internal corrosion, a new section of wire may need to be spliced in.
   Est. part cost: $15-$40
2. Failed Right Rear Wheel Speed Sensor 🟡 Medium Probability → Shop ABS Wheel Speed Sensor The sensor is exposed to road debris, water, and heat, leading to eventual failure. An erratic signal is a common failure mode for this part.
   How to confirm: Using a scan tool that can read live data, monitor the right rear wheel speed while driving. If the reading drops to zero, is erratic, or doesn't match the other wheels, the sensor is likely bad (assuming wiring is confirmed good). A good sensor can also be tested with a multimeter; resistance values can be compared to a new sensor.
   Typical fix: Replace the right rear wheel speed sensor.
   Est. part cost: $25-$80
3. Damaged or Debris on Tone Ring ⚪ Low Probability The tone ring (or reluctor ring) is part of the rear axle shaft or wheel hub assembly and can be damaged by a failing wheel bearing or become obstructed by rust or metallic debris.
   How to confirm: After removing the wheel speed sensor, use a flashlight to look inside the mounting hole. Slowly rotate the wheel hub and inspect the toothed ring for missing teeth, cracks, or heavy rust buildup. On some models, the tone ring is pressed onto the axle shaft behind the bearing and seal.
   Typical fix: If the tone ring is damaged, the entire wheel hub assembly or the axle shaft with its pressed-on ring must be replaced.
   Est. part cost: $100-$250

Rare But Worth Checking

• Failing Electronic Brake Control Module (EBCM): → Shop ABS Control Module This is rare and should only be considered after the sensor, wiring, and tone ring have been confirmed to be in good condition. An EBCM failure typically sets multiple wheel speed sensor codes, not just one. Diagnosis involves checking for the proper 12V supply and bias voltage from the module to the sensor connector.

Diagnosis Steps

1. Connect an OBD-II scanner capable of reading ABS codes to confirm C0050 is present. Note any sub-codes (e.g., 0F, 18, 5A) 🎬 Watch: How to troubleshoot specific sub-codes like 05 and 0F. as they can help pinpoint the fault type.
2. Use the scanner's live data function to monitor the speed of all four wheels while driving in a straight line. Observe if the right rear wheel's reading is erratic, drops to zero, or differs significantly from the others.
3. Raise and secure the rear of the vehicle. Visually inspect the entire right rear wheel speed sensor wiring harness for chafing, breaks, or corrosion.
4. Disconnect the sensor and inspect the connector terminals for corrosion, moisture, or pins that have pulled out of the connector body.
5. Check the harness routing. Ensure it is not stretched tight or wrapped around the flexible brake hose.
6. If no visual faults are found, test the wiring. Disconnect the harness at the sensor and the EBCM. Use a multimeter to check for continuity on both wires and ensure there are no shorts to ground or to each other. Wiggle the harness during testing to find intermittent breaks.
7. If the wiring tests good, remove the sensor (typically held by a single T30 Torx or Allen bolt). Inspect the sensor tip for damage or debris.
8. Look into the sensor mounting hole and inspect the tone ring on the hub/axle for damage, heavy rust, or metallic debris.
9. If the wiring and tone ring are good, the most likely cause is a faulty sensor. You can confirm by comparing its resistance reading to a known good sensor.

Parts You'll Likely Need

• Rear Wheel Speed Sensor (OEM #22739481) — This is the most commonly replaced part to fix a C0050 code when the wiring is confirmed to be intact. It fits a wide range of Express and Savana vans.
  Trusted brands: ACDelco, Dorman, Standard Motor Products (SMP), Delphi
  OEM price range: $60-$90
  Aftermarket price range: $25-$60
• Rear Wheel Speed Sensor Connector (OEM #PT2183 (Connector Asm)) — Often the failure point is the connector itself or the wires leading into it, as noted in GM's service bulletins. Replacing the pigtail is a common repair.
  Trusted brands: ACDelco, Dorman (e.g., 645-746, 645-134)
  OEM price range: $25-$40
  Aftermarket price range: $15-$30

Related Codes That Often Appear With This One

• C0045 — This is the code for the Left Rear Wheel Speed Sensor Circuit. TSB #PIT4648D mentions that C0045 and C0050 can appear together, suggesting a common issue with the rear axle wiring harness that could affect both sides.
• U0415 — Invalid Data Received From Electronic Brake Control Module. This code can be set in other modules (like power steering) because they rely on valid speed data from the EBCM, which is not available when C0050 is present.

Technical Service Bulletins (TSBs) & Recalls

• PIT4648D: Warns of ABS light with C0045/C0050 due to wires pulling out of the wheel speed sensor connector terminals from improper harness routing.
• 18316: Describes how an erratic signal causes a C0050 0F and illuminates multiple warning lights.
• PIT5623A: Mentions an investigation into intermittent C0050 codes on dual rear wheel models, advising no repairs at the time.
• PIT4648D (2009): An earlier version of the bulletin concerning ABS lights and C0045/C0050 codes.

Platform-Specific Known Issues

• TSB #PIT4648D specifically calls out that the wheel speed sensor wires can be pulled from their terminals at the connector due to improper harness routing around the brake hose.
• TSB #18316 notes that an erratic signal from the sensor will set a C0050 0F, illuminating the ABS, Stabilitrak, and Traction Control lights.
• For vans with dual rear wheels, TSB #PIT5623A noted that an intermittent C0050 Sym0f was under investigation by GM engineering, indicating a potentially unique issue for that specific configuration. The tone ring for dually models may also be a specific part number (e.g., GM 84757387).
• Owners and mechanics frequently report finding hidden corrosion inside the wiring loom, sometimes several feet from the sensor, which causes high resistance and triggers the code.

Mechanic-Grade Diagnostic Values

• Wheel Speed Sensor Internal Resistance — expected: 850 - 1350 Ohms. Failure: A reading outside this range, or an open loop (OL) reading, indicates a failed sensor.
• Wheel Speed Sensor AC Voltage Output — expected: Greater than 100 mV AC while spinning the wheel by hand.. Failure: No or very low AC voltage produced while the wheel is spinning points to a dead sensor or a damaged tone ring.
• Wiring Harness Continuity — expected: Less than 1.0 Ohm from the EBCM connector to the sensor connector on each wire.. Failure: High resistance (e.g., millions of ohms) or an open loop (OL) reading indicates a broken wire or severe corrosion in the harness.

Hidden / Shadow Codes Worth Checking

• C0050 0F: Indicates the EBCM has detected an erratic signal from the wheel speed sensor. This is often caused by a failing sensor, debris on the tone ring, or intermittent wiring connection. (see via Requires a professional scan tool (like the GM GDS2/Tech2) capable of reading GM-specific symptom bytes.)
• C0050 18: Indicates the signal amplitude from the sensor is too low or missing. This can be caused by a large air gap between the sensor and tone ring, a damaged tone ring, or an open circuit in the wiring. (see via Requires a professional scan tool (like the GM GDS2/Tech2) capable of reading GM-specific symptom bytes.)
• C0050 5A: Indicates the signal is not plausible when compared to the other wheel speed sensors. For example, if three wheels report 30 MPH and one reports 0 MPH. This points to a complete loss of signal. (see via Requires a professional scan tool (like the GM GDS2/Tech2) capable of reading GM-specific symptom bytes.)

Wiring & Ground Locations

• EBCM Connector Pins 3 & 4 — At the main connector for the Electronic Brake Control Module (EBCM), which is typically located on the driver's side frame rail near the front of the vehicle.. On some GM trucks of this era, Pin 3 (Green/Yellow) is the 12V supply from the EBCM to the sensor, and Pin 4 (Violet) is the signal return wire. These are the specific pins to test for continuity back to the sensor connector.
• Sensor Connector Wires — At the 2-wire connector that plugs directly into the right rear wheel speed sensor.. The wires are typically Gray/Yellow and Violet. These are the wires referenced in TSBs that can pull out of the connector or corrode internally.
• Connector X101 — A large chassis harness connector located in the front engine compartment area.. This is a major junction connector between the main body harness and the front chassis harness. A communication or power issue for the EBCM could potentially be traced back to corrosion or a bad pin fit at this location.

Real Owner Repair Stories

• YouTube video by 'Dre's Cars' (2018 Chevrolet Express 2500 with 40,000 miles) — ABS light was on with a current code C0050.
  ❌ Tried (didn't work) A new sensor was already tried by the customer before bringing it to the shop.
  ✅ What actually fixed it The technician found two separate breaks in the wiring harness. One corroded wire was found near the sensor connector, and another was found further down the harness. The mechanic bypassed the bad sections by running a new wire, which resolved the code.
• YouTube video by 'Phillip Bailey' (2017 GMC Sierra (similar platform/wiring)) — ABS and Traction Control lights on, active code C0050.
  ❌ Tried (didn't work) The wheel speed sensor had already been replaced, but the problem persisted.
  ✅ What actually fixed it Using a multimeter to test continuity from the EBCM connector to the sensor connector revealed an open circuit (mega-ohms of resistance). Wiggling the harness caused the reading to fluctuate. The technician untaped the harness near the sensor and found a wire with green corrosion that was broken internally. Repairing the single wire and cleaning the connector fixed the issue.

Model Year Variations Within This Range

• 2013-2017 (Dual Rear Wheel models): TSB #PIT5623A specifically mentions an ongoing engineering investigation into intermittent C0050 Sym0f codes on vans with dual rear wheels. This suggests there may be a unique failure mode or part difference on dually models that was not fully resolved or documented as of the bulletin's publication in 2018.