C0045 on 2013-2016 Chevrolet Malibu: Left Rear Wheel Speed Sensor Circuit Causes and Fixes

What's Unique About the 2013-2016 Chevrolet Malibu

On this generation of Chevrolet Malibu, the wheel speed sensor itself is a simple magnetic pickup, but the signal comes from a magnetic encoder ring integrated into the sealed wheel hub and bearing assembly. This encoder ring is notoriously prone to cracking, collecting metallic 'fuzz' (ferrous debris), or having pieces break off, which causes an erratic signal. This is a well-documented failure across many GM vehicles sharing this platform. While the code flags the 'sensor circuit,' the root cause is very frequently the mechanical failure of this ring, making replacement of the entire wheel hub assembly the common fix, not just the sensor or its wiring.

Generation note: The 2013-2016 period covers two distinct Malibu generations. The 8th Generation includes 2013, 2014, 2015, and the 2016 'Limited' model. The 9th Generation began in 2016 with an all-new body style. While the cause of the code is the same (hub/sensor/wiring), the part numbers for the wheel hub assembly and sensor are different between these two generations.

Symptoms You May Notice

• ABS warning light is on
• StabiliTrak / Traction Control warning light is on
• "Service StabiliTrak" or "Service Traction Control" message on the driver information center
• Loss of anti-lock braking function (wheels may lock and skid during hard braking)
• Loss of traction and stability control
• In some cases, a grinding or clicking noise from the rear wheel area at low speeds.

Most Likely Causes

1. Cracked or Contaminated Magnetic Encoder Ring on Wheel Hub 🔴 High Probability The magnetic ring integrated into the rear hub assembly is exposed to the elements and can become brittle with age, leading to cracks or allowing metallic debris to stick to it. This is a well-documented failure mode for this platform, as noted in GM TSB PIC5428G.
   How to confirm: Remove the 10mm bolt holding the wheel speed sensor and pull the sensor out of the knuckle. Use a light to visually inspect the magnetic ring on the hub. Look for visible cracks, missing chunks, or a coating of metallic 'fuzz'. A scan tool showing an erratic signal (C0045-0F) strongly points to this cause. Even a small missing piece will disrupt the signal.
   Typical fix: Replace the entire left rear wheel hub and bearing assembly. The magnetic ring is not serviced separately. The hub can be seized into the aluminum knuckle and may require significant force with a hammer to remove.
   Est. part cost: $80-$200
2. Damaged Wheel Speed Sensor Wiring or Connector 🟡 Medium Probability → Shop ABS Wheel Speed Sensor The wiring harness in the wheel well is susceptible to damage from road debris, moisture intrusion leading to corrosion (green crust), or chafing against suspension components. A common failure point is right at the connector where moisture gets past the seal, corroding the pins for the gray and black wires. Manufacturer Bulletin #PIT5499B notes that technicians should specifically inspect the Electronic Brake Control Module connector for water intrusion or corrosion when C0045 is present.
   How to confirm: Visually inspect the wiring harness from the sensor connector back into the main loom. Peel back any protective sheathing and look for broken wires, chafed insulation, or corrosion inside the connector pins. A multimeter can be used to check for continuity between the sensor connector and the EBCM connector. If the code is 'hard set' and won't clear even when stationary, it often points to an electrical fault like this.
   Typical fix: Repair the broken wire(s) using solder and heat-shrink tubing or replace the pigtail connector if it is corroded. In some cases, the entire sensor harness needs to be replaced.
   Est. part cost: $15-$50
3. Failed Wheel Speed Sensor ⚪ Low Probability → Shop ABS Wheel Speed Sensor Manufacturer Bulletin #PIE0533A discusses conditions where the wheel speed sensor becomes inoperative, leading to DTC C0045.
   How to confirm: If the wiring and hub encoder ring are confirmed to be in good condition, the sensor itself may have an internal failure. This is best confirmed by swapping the left and right rear sensors (if the wiring harness length allows) to see if the code follows the sensor (e.g., C0045 becomes C0050). This is the least likely cause on this platform.
   Typical fix: Replace the left rear wheel speed sensor harness. The sensor and harness are typically sold as one unit.
   Est. part cost: $20-$45

Rare But Worth Checking

• Failed Electronic Brake Control Module (EBCM): → Shop ABS Control Module This is very uncommon. The EBCM should only be suspected if the hub, sensor, and all associated wiring have been tested and confirmed to be good. This is a last resort diagnosis.

Diagnosis Steps

1. Connect a scan tool capable of reading ABS codes. Confirm C0045 is present and note any symptom bytes (e.g., -0F for erratic signal, -06 for open circuit).
2. Use the scan tool's live data function to monitor all four wheel speeds while driving slowly in a straight line. Observe if the Left Rear speed reads 0 MPH, drops out, or is erratic compared to the other three.
3. Safely raise and support the rear of the vehicle.
4. Remove the left rear wheel.
5. Locate the wheel speed sensor inserted into the back of the steering knuckle. It is held by a single 10mm bolt (or T30 on some related models).
6. Disconnect the sensor's electrical connector and inspect for corrosion (green crust) or damaged pins.
7. Remove the sensor and carefully inspect the magnetic encoder ring on the face of the wheel hub. Use a bright light and rotate the hub slowly. Look for cracks, missing sections, or a build-up of metallic debris.
8. If the ring is damaged, the hub assembly must be replaced. This is the most likely outcome.
9. If the ring looks perfect, thoroughly inspect the wiring harness for any signs of damage, chafing, or corrosion, paying close attention to the area near the connector.
10. If no visual faults are found, use a multimeter to perform circuit integrity tests (continuity, short-to-ground) on the harness between the sensor connector and the EBCM.

Parts You'll Likely Need

• Rear Wheel Hub and Bearing Assembly (OEM #ACDelco 25956213 (8th Gen, 2013-2016 Limited) / ACDelco 13543412 (9th Gen, 2016+)) — This is the most common fix because the integrated magnetic encoder ring fails, causing the erratic signal that triggers code C0045.
  Trusted brands: ACDelco, MOOG, Timken, SKF, Detroit Axle
  OEM price range: $140-$220
  Aftermarket price range: $80-$160
• Rear ABS Wheel Speed Sensor Harness (OEM #23483151 (8th Gen)) — This is needed if a wiring inspection reveals a broken wire, corrosion, or an internal sensor fault after the hub has been ruled out. Aftermarket pigtails like Dorman 970-040 are also available for splice-in repair.
  Trusted brands: ACDelco, Dorman, Standard Motor Products (SMP)
  OEM price range: $35-$50
  Aftermarket price range: $15-$30

Related Codes That Often Appear With This One

• C0050 — This is the identical code for the Right Rear wheel. It is common for both rear wheel hubs to fail around the same time due to similar wear, causing both codes to appear together.
• U0415 — This code means 'Invalid Data Received From EBCM' and is often set in other modules (like Power Steering) as a direct result of the C0045 fault. The primary fault lies with the wheel speed circuit, and this U-code will typically clear once C0045 is resolved. Manufacturer Bulletin #PIT5499B notes that U0415 may be found alongside C0045 during diagnosis.
• C0800 — Manufacturer Bulletin #PIC5837 notes that a technician may find DTC C0800 sym 07 along with C0045, often accompanied by a "Service Stability" message.

Technical Service Bulletins (TSBs) & Recalls

• PIC5428G: Addresses metallic debris on the magnetic encoder ring causing wheel speed sensor codes (C0035-C0050 with symptom bytes 18, 5A, 0F). Recommends inspection and cleaning.
• 16-NA-348: Recommends installing new dust deflectors (P/N 23203995/23203996) when replacing rear wheel bearings on 2014 models to prolong bearing life.
• PIC5837: Notes that if C0045 is found with C0800 sym 07, technicians should follow published service information for the wheel speed sensor code first.
• PIE0533A: Provides engineering information regarding inoperative wheel speed sensors and associated DTCs including C0045.
• PIT5499B: Advises inspection of the Electronic Brake Control Module connector for water intrusion when codes like C0045 and U0415 are present.

Platform-Specific Known Issues

• GM issued Technical Service Bulletin (TSB) #PIC5428G which notes that metallic debris collecting on the magnetic encoder ring is a common cause for this code and its variants (C0035, C0040, C0050) with symptom bytes 18, 5A, or 0F. The TSB suggests cleaning the ring may be a sufficient repair, but warns not to use magnetic tools for cleaning.
• Another TSB (#16-NA-348) for 2013-2014 models advises installing improved dust deflectors (shields) during any rear wheel bearing replacement to better protect them from contamination, suggesting an underlying issue with debris intrusion.
• Owners performing a DIY hub replacement report that the hub is often seized into the aluminum knuckle due to galvanic corrosion and requires significant force with a large hammer or a hub puller tool to remove. Cleaning the knuckle bore thoroughly and applying anti-seize compound is critical for reassembly.

Mechanic-Grade Diagnostic Values

• Wheel Speed Sensor Resistance (Passive Sensor Type) — expected: 850-1350 Ohms across the sensor pins.. Failure: A reading of infinite resistance (Open Loop) or near zero (short circuit) indicates a failed sensor.
• Wheel Speed Sensor AC Voltage Output (Passive Sensor Type) — expected: Greater than 100mV AC when spinning the wheel by hand.. Failure: No AC voltage, or voltage significantly below 100mV, indicates a failed sensor or a problem with the magnetic encoder ring.
• EBCM Voltage Threshold for Open Circuit — expected: Normal operating voltage is below 4.25V.. Failure: If the EBCM detects the sensor signal circuit voltage is greater than 4.25V and the return circuit is less than 0.75V for 0.02 seconds, it will set the code for an open circuit.
• EBCM Voltage Threshold for Short to Ground — expected: Normal operating voltage is above 0.75V.. Failure: If the EBCM detects both the sensor signal and return circuit voltages are less than 0.75V for 0.02 seconds, it will set the code for a short to ground.

Hidden / Shadow Codes Worth Checking

• C0045 06: Indicates Left Rear Wheel Speed Sensor Circuit Low Voltage/Open. This points specifically to an open wire, a poor connection, or a complete sensor failure. (see via A professional scan tool like the GM GDS2 or high-end aftermarket scanner that can read manufacturer-specific symptom bytes.)
• C0045 0F: Indicates Left Rear Wheel Speed Sensor Circuit Signal Erratic. This is the most common symptom byte for this issue and strongly points to a damaged/contaminated magnetic encoder ring on the hub. (see via A professional scan tool like the GM GDS2 or high-end aftermarket scanner.)
• C0045 18: Indicates Left Rear Wheel Speed Sensor Circuit Low Signal Amplitude. This suggests a weak signal, which could be from a large air gap, heavy contamination, or a failing sensor. (see via A professional scan tool like the GM GDS2 or high-end aftermarket scanner.)
• C0045 5A: Indicates Left Rear Wheel Speed Sensor Circuit Not Plausible. The EBCM is receiving a signal, but it doesn't make sense compared to the other wheel speeds (e.g., three wheels at 30 MPH, one at 5 MPH). (see via A professional scan tool like the GM GDS2 or high-end aftermarket scanner.)

Wiring & Ground Locations

• EBCM Connector X1, Pin 21 — At the Electronic Brake Control Module (EBCM), typically located on the ABS hydraulic unit in the engine bay.. This is the Left Rear Wheel Speed Sensor Signal wire (often a Light Blue wire). A voltage or continuity test can be performed here to check the integrity of the circuit from the sensor to the module.
• EBCM Connector X1, Pin 8 — At the Electronic Brake Control Module (EBCM), on the same connector as the signal wire.. This is the Left Rear Wheel Speed Sensor Low Reference (ground) wire (often a Red wire). This pin is used to complete the circuit test for continuity and resistance.

Real Owner Repair Stories

• YouTube channel 'JustDoItYourself' (2014 Chevrolet Malibu) — ABS light on, 'Service StabiliTrak' and 'Service Brake Assist' messages on the dash. Scan tool showed C0045 with symptom byte for 'signal erratic'.
  ❌ Tried (didn't work) The video proceeds directly to the most likely cause.
  ✅ What actually fixed it The video diagnoses the issue by observing the live data, which shows the left rear wheel speed is erratic. The technician replaced the entire left rear wheel hub and bearing assembly, which resolved the code and warning lights.
• YouTube channel 'C0045 GMC Terrain,Chevy Malibu, (All GM) common failure point' (GMC Terrain (platform shared with Malibu)) — ABS and Stabilitrak lights on with code C0045.
  ❌ Tried (didn't work) The video notes that swapping sensors is a valid diagnostic step, but the issue is often not the sensor itself.
  ✅ What actually fixed it The technician found corrosion inside the wiring harness connector for the wheel speed sensor. The gray and black wires were corroded, causing an open/high resistance in the circuit. Repairing the wiring fixed the issue. This was identified as a very common failure point due to moisture intrusion past the connector seal.

Documented NHTSA Reports

• An owner reported in NHTSA ODI #11165895 that their service center identified code C0045 and recommended replacing the left rear hub bearing assembly to resolve intermittent stability control messages.
• NHTSA ODI #11399819 describes a vehicle where C0045 appeared alongside fuel system codes P0463 and P069E, illustrating how multiple unrelated faults can sometimes trigger simultaneously.

Diagnostic Flowchart

Used vs. New Parts: Buying Guide for This Vehicle

When a used part is the smart pick: A used wiring harness pigtail from a junkyard is a viable option if your original connector is corroded or damaged, as long as the donor part is clean and free of corrosion. A complete used hub assembly is NOT recommended, as the bearing and integrated magnetic encoder are wear items with no visible way to determine their remaining lifespan.

Donor-vehicle mileage cap: roughly under 80000 miles for the part to have meaningful remaining life.

What to inspect on the donor part:

• For a wiring pigtail, inspect for any signs of green corrosion on the copper pins.
• Check that the plastic connector housing is not brittle or cracked.
• Ensure the wire insulation is flexible and not chafed or cut.

Aftermarket brands forum-validated for this vehicle:

• Timken: Often considered a top-tier choice, sometimes exceeding OEM quality.
• SKF: Another premium brand with a strong reputation for quality and durability, on par with Timken.
• MOOG: Generally considered a good, reliable mid-tier option, though some users note a decline in quality compared to their older products.

Brands owners have reported issues with on this vehicle:

• Unbranded or 'white box' parts from online marketplaces. While very cheap, they have a high failure rate, with many users reporting the new bearing is noisy or the ABS sensor is dead on arrival.

Real Owner Stories

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

Related OBD-II Codes

• C0050 — Right Rear Wheel Speed Sensor Circuit. This is the direct counterpart to C0045 for the opposite wheel. It is caused by the exact same failures, such as a cracked magnetic ring or wiring issue, and is often mentioned in the same TSBs (PIC5428G, PIC5837) and repair guides.
• C0035 — Left Front Wheel Speed Sensor Circuit. This code points to the front wheel on the same side. TSB PIC5428G and Bulletin #PIE0533A confirm that the front hubs can suffer from the same issue of metallic debris accumulating on the magnetic encoder ring, causing this code.
• C0040 — Right Front Wheel Speed Sensor Circuit. This is the code for the front passenger side wheel. Like the other wheel speed sensor codes on this platform, it is commonly caused by a contaminated or damaged magnetic encoder ring on the hub, as noted in TSB PIC5428G and Bulletin #PIC5837.

Frequently Asked Questions