C0050 on 2008-2012 Chevrolet Malibu: Right Rear Wheel Speed Sensor Circuit Fault Guide

What's Unique About the 2008-2012 Chevrolet Malibu

For this generation of Malibu, like many other GM Epsilon platform vehicles from the era (such as the Pontiac G6 and Saturn Aura), the C0050 code is frequently caused by external factors rather than an outright sensor failure. A key issue, identified in GM Technical Service Bulletin PIC5428G, is the accumulation of ferrous metallic debris on the magnetic encoder ring on the back of the wheel hub. This debris disrupts the sensor's reading, often setting symptom bytes like 0F (erratic signal) or 18 (low signal amplitude). Another common failure is the magnetic ring itself cracking or breaking apart, which also causes a loss of signal.

Symptoms You May Notice

• ABS warning light is on
• Traction Control (TC) or StabiliTrak warning light is on
• "Service StabiliTrak" or "Service Traction Control" message on the driver information center (DIC)
• ABS may activate unnecessarily at low speeds, causing a grinding or pulsating feeling in the brake pedal.
• A brief, intermittent clicking or ratchet-like noise from the wheels at low speeds.

Most Likely Causes

1. Debris on Wheel Hub Magnetic Encoder Ring 🔴 High Probability The design of the exposed magnetic ring on the inboard side of the hub makes it susceptible to attracting metallic dust and road grime, as noted in TSB PIC5428G. This is the most common cause across the GM Epsilon platform.
   How to confirm: Visually inspect the magnetic ring on the back of the right rear wheel hub. Look for a build-up of dark, metallic, fuzzy-looking debris. An ABS-capable scan tool may show an erratic signal, often with symptom byte C0050 0F.
   Typical fix: Thoroughly clean the magnetic ring with a soft nylon brush and brake cleaner. Do not use a magnetic tool or a hard scraper, as this can damage the ring. This repair often requires no parts.
   Est. part cost: $5-$15
2. Cracked or Damaged Magnetic Encoder Ring 🟡 Medium Probability Over time, the magnetic material can become brittle and break apart due to stress, corrosion, and temperature cycles.
   How to confirm: Visually inspect the magnetic ring for visible cracks, chips, or missing sections. A scan tool will typically show a complete loss of signal (0 MPH) or an erratic signal from that wheel.
   Typical fix: The magnetic ring is integrated into the wheel hub and bearing assembly. The entire right rear wheel hub assembly must be replaced.
   Est. part cost: $80-$220
3. Damaged Wheel Speed Sensor Wiring or Connector 🟡 Medium Probability → Shop ABS Wheel Speed Sensor The wiring harness is exposed to the elements and constant suspension movement, which can lead to chafing, corrosion, or broken wires, especially near the connector where moisture can intrude.
   How to confirm: Visually inspect the wiring harness from the sensor to the vehicle body for any signs of damage, green corrosion in the connector, or loose pins. A multimeter can be used to check for continuity and shorts in the wiring between the sensor connector and the EBCM.
   Typical fix: Repair the damaged section of wire or replace the pigtail connector. Ensure the repair is properly sealed against moisture. The pigtail connector is often available as a separate part.
   Est. part cost: $15-$40
4. Failed Wheel Speed Sensor / Hub Assembly ⚪ Low Probability → Shop Hub Assembly While less common than debris or wiring issues, the internal sensor electronics can fail. The wheel bearings themselves are also a known wear item on this platform.
   How to confirm: After confirming the wiring is good and the magnetic ring is clean and intact, the sensor itself is the likely culprit. An ABS scan tool showing 0 MPH from the right rear wheel points to a failed sensor. A loose or noisy wheel bearing can also cause this code.
   Typical fix: The wheel speed sensor is integrated into the wheel hub assembly on this vehicle. The entire right rear hub assembly must be replaced.
   Est. part cost: $80-$220

Rare But Worth Checking

• Failed Electronic Brake Control Module (EBCM): → Shop ABS Control Module This is very rare. Before condemning the EBCM, all other possibilities (sensor, hub, wiring) must be exhaustively ruled out. This would typically be accompanied by other wheel speed sensor trouble codes or communication faults. Manufacturer TSB Bulletin #PIC5837 notes that if C0800 symptom 07 is found with C0050, technicians should follow the diagnostics for C0050 first.

Diagnosis Steps

1. Connect an ABS-capable scan tool to verify code C0050 is present and check for any specific symptom bytes (e.g., 0F for erratic signal, 18 for low signal, 5A for implausible signal).
2. Use the scan tool's live data function to monitor all four wheel speed sensors while driving. Confirm that the right rear sensor reads 0 MPH or provides an erratic signal compared to the others.
3. Safely lift and support the vehicle and remove the right rear wheel.
4. Visually inspect the wheel speed sensor wiring harness and connector for any obvious damage, chafing, or corrosion. Pay close attention to the section of harness in the wheel well.
5. Locate the magnetic encoder ring on the inboard side of the wheel hub assembly. Thoroughly inspect it for cracks or missing chunks.
6. Whether you see debris or not, thoroughly clean the magnetic encoder ring with a dry, soft nylon brush per TSB PIC5428G. Use brake cleaner only if necessary and avoid damaging the bearing seal.
7. Clear the codes and test drive the vehicle. If the code returns immediately, the problem is likely a damaged ring or a faulty sensor/wiring.
8. If the code persists, perform a detailed circuit integrity test (checking for voltage, ground, and signal) on the wiring harness back to the EBCM. A broken wire is a common find.
9. If the ring is clean, intact, and the wiring tests good, the wheel hub/bearing assembly has failed and requires replacement.

Parts You'll Likely Need

• Rear Wheel Hub and Bearing Assembly (OEM #25900716) — The most common permanent fix, as the magnetic encoder ring and wheel speed sensor are integrated into this single unit. Failure of either component requires replacing the whole assembly. 🎬 See this walkthrough on replacing the rear wheel hub assembly.
  Trusted brands: ACDelco, Dorman, MOOG, Timken
  OEM price range: $150-$250
  Aftermarket price range: $80-$180

Related Codes That Often Appear With This One

• C0045 — This is the code for the Left Rear Wheel Speed Sensor Circuit. It's common to see both rear sensor codes if there's a shared wiring issue or if both hubs are failing around the same time due to age/mileage or have debris.
• U0415 — Invalid Data Received From Electronic Brake Control Module. If the power steering module loses a valid wheel speed signal, it may set this code and increase steering effort as a default action.
• C0800 — Device Power 1 Circuit. TSB Bulletin #PIC5837 indicates this code may appear with C0050 when a "Service Stability" message is displayed.

Technical Service Bulletins (TSBs) & Recalls

• PIC5428G: Addresses ABS/Traction/Stabilitrak lights with codes C0035-C0050, identifying metallic debris on the hub's magnetic encoder ring as a primary cause and advising cleaning as the first repair step. This TSB applies to a wide range of GM vehicles, including the 2008-2012 Malibu. Note: This TSB was later superseded by 17-NA-047, but the diagnostic advice remains the same.
• Bulletin #PIC5837: Notes that a "Service Stability" message may be displayed with DTC C0800 sym 07 alongside wheel speed sensor codes like C0050.

Platform-Specific Known Issues

• GM Technical Service Bulletin PIC5428G specifically calls out that codes C0035 through C0050 are frequently caused by ferrous metallic debris on the magnetic encoder ring, and that cleaning should be the first step before any parts are replaced.
• A video from a technician working on a 2013 Malibu showed a corroded wire inside the harness 🎬 Watch: How to find and fix a broken sensor wire. on the body side of the connector was the root cause, even after the hub had been replaced.

Mechanic-Grade Diagnostic Values

• Wheel Speed Sensor Resistance (Passive Sensor) — expected: 800 - 1,500 Ohms is a typical range for passive sensors. Some sources cite up to 2,000 Ohms.. Failure: An open circuit (OL) or a reading significantly outside the expected range indicates a failed sensor.
• Wheel Speed Sensor AC Voltage Output (Passive Sensor) — expected: Greater than 100-250mV AC when the wheel is spun by hand at about one revolution per second. Voltage should increase with speed.. Failure: Little to no AC voltage produced when the wheel is spinning points to a failed sensor or a problem with the magnetic ring.
• Wheel Speed Sensor Supply Voltage (Active Sensor) — expected: The sensor receives a reference voltage (typically 5V or 12V) from the EBCM on one wire and provides a ground on another.. Failure: Absence of reference voltage or a bad ground points to a wiring issue or a problem with the EBCM, not the sensor itself.

Hidden / Shadow Codes Worth Checking

• C0050 00: General circuit malfunction, indicating a potential open wire, short to ground, or high resistance in the circuit. (see via GM-specific scan tool (Tech2, GDS2) or high-end professional scanner.)
• C0050 0F: Erratic Signal. The EBCM receives a signal, but it's inconsistent, noisy, or drops out. This is frequently caused by metallic debris on the magnetic encoder ring. (see via GM-specific scan tool (Tech2, GDS2) or high-end professional scanner.)
• C0050 18: Signal Amplitude Less Than Minimum. The signal from the sensor is too weak. This can be caused by an excessive air gap, debris, or high resistance in the wiring. (see via GM-specific scan tool (Tech2, GDS2) or high-end professional scanner.)
• C0050 5A: Signal Not Plausible. The signal from the sensor doesn't make sense compared to other vehicle sensors (e.g., reading 5 mph while others read 60 mph). This often points to a damaged/cracked encoder ring or an intermittent wiring fault. (see via GM-specific scan tool (Tech2, GDS2) or high-end professional scanner.)

Scan Tool Commands That Help

• GDS2 / Tech2: Live Data > EBCM > Wheel Speed Sensors — This is the primary diagnostic step. Use this to monitor the MPH/KPH reading from all four sensors simultaneously while driving. The faulty sensor will read 0, lag behind, or show erratic values compared to the others.
• GDS2 / Tech2: Clear DTCs — Used after a repair (like cleaning the hub or replacing a part) to clear the code from the EBCM's memory. The ABS/StabiliTrak lights will not turn off until the code is cleared and the module confirms the fault is gone.

Wiring & Ground Locations

• EBCM (Electronic Brake Control Module) — Located on the driver's side of the engine compartment, mounted to the Brake Pressure Modulator Valve (BPMV) assembly, which has multiple brake lines running into it. It's often found near the strut tower.. This module receives the signal from the right rear wheel speed sensor. All circuit testing ultimately leads back to the EBCM connector.
• Right Rear Wheel Speed Sensor Circuit Wires — At the EBCM connector: The signal wire is typically Dark Blue and located at Pin 3. The low reference (ground) wire is typically Light Blue/Black and located at Pin 4.. Knowing the specific pin locations and wire colors is critical for performing continuity and voltage tests between the sensor connector and the EBCM, allowing a technician to isolate a break or short in the harness.
• G109 (Ground) — Located on the left front corner of the engine compartment.. This is a primary ground point for the EBCM. While a bad ground here would likely cause multiple system codes and not just C0050, verifying it is clean and tight is a good practice during a complex electrical diagnosis.

Real Owner Repair Stories

• Chevy HHR Network Forum user 'PanamaJack' (Chevrolet HHR (shares Epsilon platform and similar ABS components with Malibu)) — ESC, traction control, and ABS lights were on. Scan showed code C0050.
  ❌ Tried (didn't work) Replaced the right rear wheel hub assembly with a new OEM part.
  ✅ What actually fixed it The problem was not resolved by the hub replacement. A forum moderator suggested the issue was likely a broken wire or bad pin in the circuit leading to the EBCM, indicated by a C0050 00 (circuit malfunction) symptom byte. The final resolution was not posted, but the diagnosis shifted from the hub to the wiring harness itself.

OEM Part Supersession History

• 25900716 → This part number appears to be stable for the specified model years, but always verify with a dealer using the vehicle's VIN. Aftermarket manufacturers will have their own equivalent part numbers (e.g., MOOG 512285). — N/A

Diagnostic Flowchart

Other Known Issues on This Vehicle

Issues unrelated to this code that are worth knowing about as an owner of this generation:

• Premature Timing Chain Wear (2.4L Ecotec) 🔴 High — Common after 80,000-120,000 miles, often accelerated by oil consumption issues. Can cause rattling noises on startup. (Ref: Multiple TSBs address related symptoms (e.g., P0016, P0014).)
• Sudden Loss of Electric Power Steering (EPS) 🔴 High — Widespread enough to trigger a major safety recall (GM Recall #14118). Can happen at any time. (Ref: Recall #14118 / NHTSA #14V153000.)
• 4T45-E / 6T40 Transmission Problems 🟠 Medium — Complaints include harsh shifting, hesitation, and in 6-speeds, failure of the 3-5-R wave plate. A recall was issued for a fractured shift cable tab on some models. (Ref: Recall #09V073000 (Shift Cable).)
• Excessive Oil Consumption (2.4L Ecotec) 🟠 Medium — Common issue due to piston ring design, can lead to low oil levels that damage other components like the timing chain. (Ref: TSB 13-06-01-003E.)
• Cracked Exhaust Manifold (2.4L Ecotec) 🟡 Low — The cast iron manifold is prone to cracking over time, causing a loud exhaust leak noise similar to a tractor.
• Faulty Door Lock Actuators 🟡 Low — A common annoyance where one or more power door locks stop working, requiring manual operation.

Used vs. New Parts: Buying Guide for This Vehicle

When a used part is the smart pick: A used wheel hub assembly is generally NOT recommended. The wheel bearing is a wear-and-tear item with a finite lifespan. The integrated magnetic encoder ring can be damaged or have lost magnetic strength over time. The cost savings are minimal compared to the risk of premature failure and having to repeat the labor-intensive repair.

Donor-vehicle mileage cap: roughly under 30000 miles for the part to have meaningful remaining life.

What to inspect on the donor part:

• Verify the donor vehicle was not involved in a collision that could have impacted the wheel/suspension.
• Inspect the magnetic encoder ring on the back of the hub for any visible cracks, chips, or deep scratches.
• Spin the bearing by hand. It should be smooth and silent. Any grinding, roughness, or play indicates it is worn out.
• Check the electrical connector pins for any signs of corrosion or damage.

Aftermarket brands forum-validated for this vehicle:

• Timken
• MOOG
• SKF
• ACDelco (Professional or Gold series)

Brands owners have reported issues with on this vehicle:

• Unbranded, 'white-box' parts from online marketplaces. These often use lower-quality bearings and seals, leading to a high rate of failure, noise, and repeat ABS/StabiliTrak issues.

Real Owner Stories

Aggregated from forums and TSBs cited above. Mileages and costs reflect what owners reported in those sources.

Related OBD-II Codes

• C0035 — Left front wheel speed sensor code; shares the same root cause of metallic debris on the encoder ring as identified in TSB PIC5428G.
• C0045 — Left rear wheel speed sensor code; often appears alongside C0050 due to similar environmental exposure or shared wiring harness issues.
• P0016 — Camshaft/crankshaft alignment code related to the 2.4L Ecotec timing chain wear, which is a known issue on this vehicle platform.
• P0014 — Exhaust camshaft position timing code; another common companion to timing chain and oil consumption issues on the Malibu's 2.4L engine.

Frequently Asked Questions