C0035 on 2013-2017 Cadillac XTS: ABS Wheel Speed Sensor Causes and Fixes

What's Unique About the 2013-2017 Cadillac XTS

For this generation of Cadillac XTS and many other GM platforms (like the Buick LaCrosse and Chevy Impala), the wheel speed sensor's magnetic encoder ring is integrated into the wheel hub and bearing assembly. A widely-circulated GM Technical Service Bulletin (TSB PIC5428G) directly addresses that ferrous metallic debris collecting on this magnetic ring can cause erratic signals and trigger code C0035. Furthermore, the wiring harness leading to the sensor is a very common failure point, where wires can break internally from stress and flexing, often with no visible damage to the outer insulation.

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
• Service StabiliTrak or Traction Control warning light is on
• Traction control and stability control systems are disabled
• A grinding or ratchet-like noise from the wheels at low speeds, which can be the ABS pump activating incorrectly.
• Cruise control is disabled
• Service Steering Message on the Driver Information Center (DIC) with heavier steering feel at low speeds.

Most Likely Causes

1. Damaged or Contaminated Wheel Hub/Bearing Assembly 🔴 High Probability A known issue documented in GM TSB #PIC5428G. The magnetic encoder ring is part of the bearing assembly and is highly susceptible to collecting metallic shavings and road debris, which disrupts the sensor signal.
   How to confirm: Visually inspect the magnetic encoder ring on the inboard side of the wheel hub for metallic shavings or debris. A professional scan tool may show symptom bytes like 18 (Signal Amplitude Less Than Minimum) or 5A (Signal Plausibility Failure), which strongly point to this issue. A user on a Tahoe forum confirmed cleaning the ring resolved the issue.
   Typical fix: In many cases, carefully cleaning the debris from the magnetic ring with a soft brush or cloth can resolve the issue. However, if the bearing itself has failed (is noisy or has play) or the ring is damaged, the entire wheel hub and bearing assembly must be replaced.
   Est. part cost: $150-$300
2. Faulty Wheel Speed Sensor Wiring Harness 🔴 High Probability The wiring harness is subject to constant movement and exposure to the elements, leading to internal wire breaks that are not visible externally. The wire can break inside the insulation from stress, especially at the flex point near the control arm.
   How to confirm: With the harness connected, gently pull and wiggle the wires while monitoring the wheel speed signal on a scan tool. A common failure point is where the harness flexes. A tug on the wire may reveal it stretching like a rubber band, indicating a break inside. A multimeter can also be used to check for continuity from the EBCM connector to the sensor connector; wiggling the harness during the test can reveal an intermittent open.
   Typical fix: Replace the faulty section of the harness with an OEM repair pigtail (GM Part #10340314). This involves cutting the old connector off and splicing the new pigtail into the body harness.
   Est. part cost: $30-$60
3. Failed Left Front Wheel Speed Sensor 🟡 Medium Probability
   How to confirm: Use a scan tool to monitor live data from all four wheel speed sensors while driving. If the left front sensor reads 0 or provides an erratic signal compared to the others, it is suspect. You can also test the sensor's resistance with a multimeter (if specifications are known) or check for a 12V supply at the harness connector with the key on.
   Typical fix: Replace the left front wheel speed sensor. It is typically held in by a single bolt on the steering knuckle. The OEM part number is 23460591.
   Est. part cost: $40-$100

Rare But Worth Checking

• Faulty Electronic Brake Control Module (EBCM): This is an expensive part and rarely the cause. It should only be considered after all other possibilities (sensor, wiring, and hub/bearing) have been thoroughly ruled out. Usually, a faulty EBCM will be accompanied by other trouble codes or communication errors.

Diagnosis Steps

1. Connect a professional scan tool capable of reading ABS codes and live data. Confirm C0035 is present and check for any specific symptom bytes (e.g., 18, 5A, 0F), as these strongly suggest debris on the hub per TSB PIC5428G.
2. View the live data stream for all four wheel speed sensors while driving slowly (5-15 mph). Compare the Left Front sensor reading to the others. An erratic, intermittent, or zero reading indicates the problem corner.
3. Raise the vehicle and remove the left front wheel. Visually inspect the wheel speed sensor and its wiring harness for any obvious damage, corrosion, or loose connections. Check that the connector is fully seated.
4. Gently pull and wiggle the sensor harness wires, especially near flex points. If the insulation stretches or feels 'spongy,' the wire is likely broken internally.
5. Disconnect the sensor and check for a 5V or 12V power supply at the harness-side connector with the ignition on. If voltage is missing or low, the problem is in the wiring harness or EBCM.
6. Remove the wheel speed sensor (usually one bolt) and inspect the magnetic encoder ring on the inboard face of the wheel hub/bearing assembly. Carefully clean off any metallic debris using a cloth or soft brush, taking care not to damage the seal.
7. If no debris is found and the wiring appears intact, test the wiring circuit with a multimeter for continuity back to the EBCM connector. An open circuit confirms a broken wire in the harness.
8. If the wiring and hub are good, the sensor itself may be faulty. It can be tested for resistance or swapped with the sensor from the other side to see if the fault code follows.

Parts You'll Likely Need

• Front Wheel Bearing and Hub Assembly (OEM #84869190 (superseded by 85689422)) — The integrated magnetic encoder ring is a common point of failure due to debris accumulation or damage. A noisy or loose bearing also necessitates replacement.
  Trusted brands: ACDelco (OEM), Timken, MOOG (Part #513288), Detroit Axle
  OEM price range: $180-$350
  Aftermarket price range: $100-$220
• Front Wheel Speed Sensor Harness (OEM #10340314) — The harness is a very common failure point due to internal wire breakage from suspension movement and flexing.
  Trusted brands: ACDelco (GM Genuine), Dorman, Michigan Motorsports
  OEM price range: $40-$70
  Aftermarket price range: $25-$45
• Front Wheel Speed Sensor (OEM #23460591 (replaces 20899215, 23136762)) — While less common than wiring or hub issues on this platform, the sensor itself can fail electronically.
  Trusted brands: ACDelco (GM Genuine), Bosch, Standard Motor Products
  OEM price range: $60-$100
  Aftermarket price range: $40-$70

Related Codes That Often Appear With This One

• C0040, C0045, C0050 — These are the codes for the other wheel speed sensors (Right Front, Left Rear, Right Rear). TSB #PIC5428G applies to all of them and indicates a similar failure pattern across the vehicle, often caused by debris on the magnetic encoder rings.
• U0415 — Invalid Data Received From Electronic Brake Control Module. This code may set in the Power Steering Control Module, causing a 'Service Steering Message' and increased steering effort at low speeds. It's a default action when the wheel speed signal is lost.

Technical Service Bulletins (TSBs) & Recalls

• PIC5428G: Addresses ABS/StabiliTrak lights and codes C0035-C0050, pointing to debris on the wheel bearing's magnetic encoder ring as a likely cause. This TSB covers a wide range of GM vehicles, including the XTS, Impala, LaCrosse, and Equinox.
• PIC5992: A diagnostic tip for older Impala and LaCrosse models that specifically calls out inspecting the front wheel speed sensor jumper harnesses for internal breaks as a primary cause for C0035/C0040.

Platform-Specific Known Issues

• A GM Technical Service Bulletin (PIC5428G) specifically identifies that DTCs C0035-C0050 with symptom bytes 18 (Signal Amplitude Less Than Minimum), 5A (Signal Plausibility Failure), or 0F are often caused by metallic debris on the magnetic encoder ring of the wheel bearing. The bulletin advises cleaning the ring as a primary repair step before replacing parts and notes that most repairs can be done without replacing the hub or sensor.

Mechanic-Grade Diagnostic Values

• Voltage at the wheel speed sensor harness connector (EBCM side) with ignition on. — expected: 4.5 - 5.5 Volts DC (on the supply wire to ground).. Failure: A reading below 4.0 Volts indicates a problem with the wiring harness or the EBCM's internal voltage regulator.
• Resistance of the wheel speed sensor itself. — expected: A few hundred to a few thousand ohms (general specification).. Failure: An open circuit (infinite resistance) or a direct short (zero resistance) indicates a failed sensor.

Hidden / Shadow Codes Worth Checking

• C0035 06: Left Front Wheel Speed Sensor Circuit Low Voltage/Open. This points to a potential break in the wire or a connector issue. (see via GM-specific scan tool like a Tech2 or GDS2.)
• C0035 0F: Left Front Wheel Speed Sensor Circuit Signal Erratic. This often corresponds to debris on the magnetic encoder ring or an intermittent wiring short. (see via GM-specific scan tool like a Tech2 or GDS2.)
• C0035 18: Left Front Wheel Speed Sensor Circuit Low Signal Amplitude. This is a strong indicator of an excessive air gap or heavy debris on the hub's magnetic ring, as noted in TSB PIC5428G. (see via GM-specific scan tool like a Tech2 or GDS2.)
• C0035 5A: Left Front Wheel Speed Sensor Circuit Not Plausible. The signal doesn't make sense compared to other vehicle sensors, often caused by debris on the hub or a failing sensor. (see via GM-specific scan tool like a Tech2 or GDS2.)

Scan Tool Commands That Help

• GDS2 / Advanced Scan Tool: Module Self-Test — Use this function on the Electronic Brake Control Module (EBCM) after verifying the sensor and wiring are good but voltage supply to the sensor is still low. A failure of the self-test can confirm an internal fault within the EBCM, such as a failed voltage regulator.

Wiring & Ground Locations

• Left Front WSS Harness Connector — At the wheel hub, connecting the wheel speed sensor to the chassis harness that runs up the suspension control arm.. This is the location for testing sensor supply voltage and performing the 'wiggle test'. The harness is a 2-wire connector. One pin is the voltage supply from the EBCM, and the other is the signal return/low reference. An internal break in either wire near this connector is the most common cause of C0035.
• EBCM Ground — The Electronic Brake Control Module is grounded to the chassis. While a specific ground point ID (e.g., Gxxx) for the XTS was not found, verifying the EBCM has a clean, tight ground connection is a valid diagnostic step if module communication is intermittent.. A poor ground at the main module can cause a variety of erratic faults, including incorrect sensor readings and false trouble codes.

Real Owner Repair Stories

• YouTube channel 'Keith Perkins' (2014 Chevrolet Impala (similar platform)) — ABS and Stabilitrak lights on, code C0035 0F (Signal Erratic).
  ❌ Tried (didn't work) Previous shop had replaced two wheel bearings., Previous shop had replaced the ABS control module., Previous shop had performed a wiring harness repair that failed.
  ✅ What actually fixed it The technician identified an internal break in both wires of the sensor pigtail harness. The copper wire was broken inside the insulation, which was not visibly damaged. The break was confirmed by pulling on the wire and seeing the insulation stretch like a rubber band. Replacing the harness pigtail (GM Part #10340314) resolved the code.
• YouTube channel 'KY Home Garage' (2013 Chevrolet Impala (similar platform)) — ABS and Stabilitrak lights on, code C0035.
  ❌ Tried (didn't work) Initial inspection did not reveal obvious damage.
  ✅ What actually fixed it After extensive testing, a broken ground wire (yellow wire) was found within the wheel speed sensor harness. The wire was broken internally from flexing and stress. Repairing the broken wire fixed the issue.

"I Checked Everything" — The Actual Cause

• The diagnostic equivalent for this electrical code is when a standard multimeter continuity test on the harness wires shows 'good,' but the fault persists. This happens because the broken ends of the wire inside the insulation may still be touching when the harness is stationary. The actual cause, an intermittent open circuit, is only revealed when the harness is moved, flexed, or stretched ('wiggle test' or 'stretch test'), which is a critical step often missed.

OEM Part Supersession History

• 84869190 → 85689422 — Part has been updated by the manufacturer. The new part is the current service replacement.
  Heads up: 85689422 also replaces part numbers 20971870, 23356814, 23498357, 84747041, 84844373, and 84878670.
• 20899215, 23136762 → 23460591 — Part has been updated by the manufacturer for the Front Wheel Speed Sensor.
• N/A → 10340314 — This is the established repair harness pigtail for this common issue.
  Heads up: Some aftermarket parts catalogs may not list this harness as a direct fit for the 2013-2017 XTS, despite it being the correct OEM repair part referenced in technical videos and TSBs for similar platforms.