C0055 on 2007-2013 GMC Yukon: Rear Wheel Speed Sensor Circuit Causes and Fixes

What's Unique About the 2007-2013 Gmc YUKON

The GMT900 platform, which includes the Yukon, Tahoe, and Silverado, uses a single sensor on the driveline for its rear wheel speed reading instead of individual sensors at each rear wheel. This design simplifies the system but also means a single sensor failure will disable ABS and StabiliTrak. The wiring for this sensor is known to chafe or get damaged where it runs over the transmission, between the firewall and the back of the engine, which is a common point of failure besides the sensor itself. A YouTube video demonstrates that for 4WD models, there is a separate pigtail harness that extends from the main harness to the sensor, and this extension is often the culprit.

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 or Traction Control warning light is on
• "Service StabiliTrak" or "Service Traction Control" message appears in the driver information center
• Cruise control is inoperative
• Harsh or erratic transmission shifting
• Inaccurate or dead speedometer reading in some cases
• Brake light may be illuminated

Most Likely Causes

1. Failed Vehicle Speed Sensor (VSS) 🔴 High Probability The sensor is exposed to heat from the transmission/transfer case and contamination, leading to eventual electronic failure. It's a very common replacement part for this platform.
   How to confirm: Use a scan tool to monitor the 'Rear Wheel Speed' or 'Vehicle Speed' PID. If the reading is zero or erratic while driving, the sensor is likely bad. The sensor is located on the rear of the transfer case (4WD) or transmission tail housing (2WD). Resistance across the two pins of a good sensor should be around 1300-1400 ohms. Some sources suggest a wider range of 1,500 to 2,900 ohms for a good sensor on similar GM trucks.
   Typical fix: Replace the Vehicle Speed Sensor. It is typically held in by a single 19mm or 13mm bolt and has a single electrical connector. The new sensor should come with a new O-ring.
   Est. part cost: $25-$70
2. Damaged Wiring or Connector 🟡 Medium Probability The wiring harness runs over the top of the transmission and is a known spot for chafing against the vehicle's body or other components, causing a short or open circuit. This is a very well-documented failure point in owner forums and repair videos.
   How to confirm: Visually inspect the entire length of the wiring harness from the sensor to where it enters the main loom. Pay close attention to the area over the transmission bellhousing, between the firewall and the back of the engine. Check the connector at the sensor for corrosion or damage. On 4WD models, there is an extension pigtail that is also a common failure point.
   Typical fix: Repair the damaged section of wire with a new piece of wire and weatherproof connectors. In many cases, owners create a new harness section to bypass the damaged area entirely. 🎬 Watch: How to trace and replace the VSS wiring harness. Replace the pigtail connector if it is corroded or damaged.
   Est. part cost: $5-$30
3. Metal Debris on Sensor Tip ⚪ Low Probability The sensor is magnetic and can attract metallic particles from normal wear inside the transmission or transfer case. Excessive buildup can disrupt the signal.
   How to confirm: Remove the sensor (one bolt) and inspect the magnetic tip. A small amount of fine paste is normal, but large shavings or a thick coating of metal can cause a problem. One owner on a forum noted that after pulling the sensor, he found it had been physically contacted by the tone ring due to a separate mechanical issue.
   Typical fix: Wipe the sensor tip clean and reinstall. If large metal chunks are present, it may indicate a more serious internal transmission or transfer case problem that requires further investigation.
   Est. part cost: $0

Rare But Worth Checking

• Faulty Electronic Brake Control Module (EBCM): This is rare, but if the sensor and wiring are confirmed to be good, the EBCM may be the issue. This was a suggested cause in some diagnostic threads after other parts were replaced. A diagnostic video on a similar platform showed how to test inputs at the EBCM to confirm if the module itself is faulty.
• Excessive Tone Wheel Movement: Manufacturer TSB #PIP4966B mentions that excessive movement of the tone wheel or output shaft inside the transmission/transfer case can cause this code. This indicates a significant mechanical problem, such as a worn slip yoke bushing, which could allow the tone ring to contact the sensor.
• Swapped Sensor Connectors: A forum moderator noted that if work was recently done on the transfer case, it's possible to accidentally swap the front and rear sensor connectors, which would immediately trigger this code.

Diagnosis Steps

1. Connect an OBD-II scanner capable of reading ABS codes to confirm C0055 is present.
2. Use the scanner's live data function to monitor the Rear Wheel Speed Sensor signal while driving. Look for dropouts, erratic readings, or a constant zero. Compare it to the front wheel speed sensor readings.
3. Locate the sensor on the rear of the transmission (2WD) or transfer case (4WD), just forward of the driveshaft yoke.
4. Thoroughly inspect the sensor's electrical connector for corrosion, pushed-out pins, or damage. Follow the wiring harness up and over the transmission, looking for any signs of chafing, melting, or breaks, especially where it runs close to the firewall.
5. If wiring looks good, remove the single bolt (often 13mm or 19mm) holding the sensor and pull it out. Inspect the magnetic tip for excessive metal debris.
6. If the sensor is clean and wiring is intact, test the circuit. TSB #PIT4815C provides detailed steps: test the signal on circuit 817 (to the instrument cluster) by connecting a multimeter set to DC voltage and pressing the Hertz button. The reading should be approximately 1.1 Hz per MPH. The raw signal from the sensor itself (circuits 821 and 822) should be an AC sine wave of about 25 Hz per MPH.
7. If the circuit tests good but the live data was bad, the sensor itself is the most likely culprit. Replace the sensor.
8. If the problem persists after replacing the sensor and verifying the wiring, the issue may be with the EBCM or an internal mechanical fault as noted in TSB #PIP4966B.

Parts You'll Likely Need

• Vehicle Speed Sensor (VSS) (OEM #ACDelco 213-4533 (supercedes older numbers)) — This sensor is the primary input for the rear wheel speed signal and is the most common failure point for code C0055.
  Trusted brands: ACDelco, Delphi, Standard Motor Products (SC168), Dorman (917-624)
  OEM price range: $45-$70
  Aftermarket price range: $25-$50
• VSS Connector Pigtail — If the connector itself is corroded or damaged, or if the wiring is broken close to the connector, replacing the pigtail is the standard repair.
  Trusted brands: Dorman, ACDelco
  OEM price range: $20-$40
  Aftermarket price range: $10-$25

Related Codes That Often Appear With This One

• P2771 — TSB #PIP4966B explicitly links C0055 and P2771 (Four-Wheel Drive (4WD) Low Switch Circuit) as potentially appearing together, suggesting a related issue in the transfer case area.
• C0710 — While not directly related to the rear VSS, issues with the StabiliTrak system can sometimes be caused by a faulty Steering Wheel Position Sensor, which sets code C0710. If C0055 is not present, this is another common cause for the 'Service StabiliTrak' message.

Technical Service Bulletins (TSBs) & Recalls

• PIP4966B: Mentions C0055 and instructs technicians to check for excess movement of the tone wheel or output shaft.
• PIT4815C: Provides specific electrical diagnostic steps for code C0055 when it appears alone, including expected Hz readings for various circuits.

Platform-Specific Known Issues

• Wiring Harness Chafing: The most significant vehicle-specific issue is the VSS wiring harness rubbing through on the top of the transmission/bellhousing area. Many owners report finding bare or broken wires (purple and green/yellow) in this location after replacing the sensor did not fix the code. A detailed repair is shown in a YouTube video by 'Average Guy DIY' where he builds a new harness section.
• TSB - Internal Mechanical Fault: TSB #PIP4966B notes that C0055 can be caused by excessive movement of the tone wheel or output shaft, indicating a mechanical issue within the transmission or transfer case, such as a worn slip yoke bushing.
• TSB - Electrical Diagnosis: TSB #PIT4815C provides a specific diagnostic step for technicians when C0055 is present with no other customer complaints. It involves checking the frequency of the signal on circuit 817.

Mechanic-Grade Diagnostic Values

• Vehicle Speed Sensor (VSS) internal resistance — expected: 1300-1426 ohms. Failure: An open loop (OL) or resistance significantly outside the expected range.
• VSS AC Signal Output (Raw) — expected: Approx. 1.0V peak-to-peak AC sine wave when the driveshaft is spinning at one revolution per second.. Failure: No signal, or a weak/distorted sine wave, indicates a bad sensor.
• VSS Signal at EBCM (Processed) — expected: A clean square wave signal. The PCM converts the VSS sine wave into a square wave before sending it to the EBCM.. Failure: A missing, erratic, or 'garbage' signal on an oscilloscope points to a problem in the circuit between the PCM and EBCM, or a faulty PCM.

Hidden / Shadow Codes Worth Checking

• C0055 00: This sub-code (symptom byte) indicates the ABS module has detected a short to ground, short to voltage, or an open/high resistance on the rear wheel speed sensor signal circuit. (see via A professional scan tool capable of reading GM-specific ABS codes, like a Tech2 or high-end Autel/Snap-on scanner.)
• C0055 5A: This sub-code indicates the ABS module has detected an erratic or implausible rear wheel speed signal. This often occurs during acceleration from a stop where the signal drops out unexpectedly. (see via A professional scan tool capable of reading GM-specific ABS codes.)

Wiring & Ground Locations

• VSS Wires — The two wires running from the VSS connector on the transmission/transfer case up over the bellhousing to the main engine harness.. These are typically a Purple wire (VSS signal) and a Green/Yellow or Yellow wire (VSS ground/low reference). Damage to these specific wires, especially in the known chafe area over the transmission, is a primary cause of code C0055.
• EBCM Ground — The Electronic Brake Control Module is located under the driver's side of the vehicle, mounted to the inside of the frame rail. The main ground for the module is typically a nearby bolt to the frame.. A poor ground connection at the EBCM can cause a host of ABS-related codes, including C0055, due to faulty signal interpretation. Cleaning this ground is a key diagnostic step.
• G103 / G104 — These are engine/cowl area grounds. G103 is often on the cowl above the brake booster, and G104 is on the rear of the driver's side cylinder head.. These grounds serve various modules, including the BCM and IPC. While not directly for the VSS, poor grounds in this area can cause communication issues between the modules that process and display the speed signal.
• EBCM Connector Pin B3 — This is a pin on the large connector for the EBCM.. A forum user with diagnostic information suggested checking continuity from the ECM connector (C1, pin 46) to the EBCM connector at pin B3 to verify the signal path between the two modules.
• Fuse #19 (Underhood) — In the main fuse block located in the engine compartment.. A video guide identifies fuse #19, a 15-amp fuse, as being related to the input speed sensor circuit on these trucks. Checking this fuse is a simple first step.

Real Owner Repair Stories

• YouTube video 'Speedometer Erratic/Twitching Won't Shift - Code C0055 Speed Sensor *SOLVED*' (1999-2006 (GMT800) Chevy/GMC Truck, 4WD. (Note: The issue is identical on the 2007-2013 GMT900 platform).) — Erratic/twitching speedometer, harsh shifting, and trouble code C0055.
  ❌ Tried (didn't work) Replacing the Vehicle Speed Sensor (VSS) on the transfer case.
  ✅ What actually fixed it The owner found that the wiring harness that runs up over the top of the transmission, between the firewall and the back of the engine, had rubbed through. Repairing the damaged wires in this harness resolved all symptoms and the code.
• PerformanceTrucks.net forum user (2007 Silverado 2WD with 4.8L V8) — ABS light on with code C0055 symptom 5A (Not Plausible). The rear wheel speed signal would drop to 0 on a scan tool during moderate acceleration from a stop, triggering the code. The speedometer continued to work correctly.
  ❌ Tried (didn't work) Cleaning the EBCM ground., Checking for power at the EBCM connector., Replacing both speed sensors on the transmission (ISS and OSS)., Replacing both front wheel hub/sensor assemblies.
  ✅ What actually fixed it The user noted that the speedometer works because the ECM can get speed data from the Transmission Control Module (TCM) over the GMLAN bus and pass it to the instrument cluster. The final resolution was not posted in the thread, but the detailed diagnosis points toward a communication or wiring issue between the ECM/TCM and the EBCM, as all sensors and grounds were verified as good.

When the Usual Fixes Don't Work

• In one documented case on a 2007 Silverado, a user replaced the VSS, both front hubs, and cleaned the EBCM ground, but the C0055 code (specifically with symptom 5A) persisted. The issue only occurred during acceleration from a stop, where the rear wheel speed signal would drop to zero on the scan tool, while the main speedometer worked fine. This suggests that even with a new sensor and good wiring, a fault in the communication path between the PCM and the EBCM, or a fault within the EBCM itself, can be the root cause. The fact that the speedometer works correctly can be misleading, as it may receive its data from the TCM over the GMLAN bus, bypassing the specific circuit used by the EBCM.

OEM Part Supersession History

• Unknown older GM part numbers → ACDelco 213-4533 (also listed as GM 19237463) — Part consolidation and design updates.
  Heads up: While listed under different part numbers (213-4533 vs 19237463), these appear to be the same part sold through different channels or branding (Gold vs GM OE). No major incompatibility issues are noted for the 2007-2013 range, but always verify fitment with the vehicle's VIN.