C0710 on 2008-2012 Chevrolet Express: StabiliTrak and Steering Sensor Fixes

What's Unique About the 2008-2012 Chevrolet EXPRESS

The Chevrolet Express, along with many other GM trucks and vans from this era, is known for setting a C0710 code due to a specific design issue. General Motors issued Technical Service Bulletin (TSB) #PI0639C, which states the cause is often excessive clearance and fretting corrosion at the steering angle sensor's electrical connector. Fretting corrosion appears as tiny black or dark smudges on the electrical terminals where micromovements have worn away protective plating. The bulletin specifically advises against replacing the sensor as a first step, instead recommending a simple fix of adding a shim and dielectric grease to secure the connection.

Diagnostic Flowchart

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

Symptoms You May Notice

• "Service StabiliTrak" message on the Driver Information Center (DIC)
• StabiliTrak/Traction Control warning light is on
• ABS light may be illuminated
• Traction control and stability control systems are disabled
• "Service Traction Control" message may also appear on the DIC.

Most Likely Causes

1. Poor Connection at Steering Angle Sensor Connector 🔴 High Probability → Shop Steering Angle Sensor As documented in GM TSB #PI0639C, the connector can have excessive clearance, leading to micromovements, high resistance, and fretting corrosion on the terminals. Fretting appears as small dark smudges on the pins.
   How to confirm: Inspect the steering angle sensor connector, located at the base of the steering column, for looseness. Wiggle the connector while observing live sensor data on a scan tool; a signal dropout confirms a bad connection. 🎬 Watch: Diagnosing the C0710 code on a Chevy Express Visually inspect the terminals for dark smudges (fretting), which may require a magnifying glass.
   Typical fix: Follow TSB PI0639C: Add a piece of adhesive shim stock (Kent Automotive P/N P40100) to the connector body to eliminate movement, clean the terminals with a dedicated nylon brush, and apply dielectric lubricant (GM P/N 12377900). 🎬 See how to apply the TSB shim and grease fix If this fails, the TSB advises replacing the harness-side connector pigtail.
   Est. part cost: $5-$30
2. Faulty Steering Angle Sensor 🟡 Medium Probability → Shop Steering Angle Sensor While less common than the connector issue, the sensor itself can fail internally, causing erratic or no signal. The TSB explicitly states NOT to replace the sensor until the connector fix has been attempted. The internal potentiometers can wear out, causing signal dropouts that are best captured on an oscilloscope.
   How to confirm: After confirming the connector is secure and wiring is intact, use a scan tool to monitor the steering angle sensor's voltage and position data while turning the steering wheel. The voltage should sweep smoothly and the angle should change consistently. Jumps, dropouts, or a fixed value indicate a failed sensor. An oscilloscope is the definitive tool to see small, rapid dropouts that a scan tool might miss.
   Typical fix: Replace the steering angle sensor (e.g., ACDelco P/N 20910871) and perform a calibration procedure with a compatible scan tool. The new sensor comes with a locking pin to keep it centered during installation. 🎬 Watch: Pro tips for replacing the steering angle sensor
   Est. part cost: $60-$150
3. Steering Angle Sensor Calibration Lost ⚪ Low Probability → Shop Steering Angle Sensor This can happen after a wheel alignment, battery replacement, or work on the steering column or suspension. If the steering shaft is not correctly indexed after a repair like a rack and pinion replacement, it can also cause this code.
   How to confirm: If the code appeared immediately after other service work, a calibration issue is likely. A professional scan tool is needed to check the calibration status and angle reading while driving straight. The reading should be 0.0 degrees when the wheels are straight.
   Typical fix: Recalibrate the steering angle sensor using a compatible professional scan tool. If the steering shaft is misaligned, it must be mechanically corrected.
   Est. part cost: $0-$150

Rare But Worth Checking

• Damaged Wiring Harness: The wiring leading to the steering angle sensor can be damaged, especially if aftermarket accessories like remote starters have been installed near the steering column. Chafing near the park brake pedal has also been noted in similar platforms.
• Faulty Electronic Brake Control Module (EBCM): In very rare cases, the EBCM, which receives and interprets the sensor's signal, can fail. This should only be considered after all other possibilities, including wiring and connectors, have been exhausted. A scan tool may show valid data from the sensor module but frozen or absent data within the EBCM live data, pointing to an internal EBCM fault.
• Vehicle Modifications: Lift kits, leveling kits, or even using a single mismatched tire can alter the vehicle's geometry, causing a conflict between the steering angle sensor and wheel speed sensors that triggers code C0710. A proper four-wheel alignment and SAS recalibration are required to fix this. One owner reported the code was resolved after replacing a mismatched tire and getting an alignment.

Diagnosis Steps

1. Read the trouble codes from the Electronic Brake Control Module (EBCM) with a scan tool capable of reading chassis codes. Note any suffix digits, like -5A (Plausibility Failure).
2. Observe live data from the Steering Angle Sensor (SAS) on the scan tool. Note the reading with the wheels straight; it should be close to 0.0 degrees.
3. Turn the steering wheel lock-to-lock. The angle reading should change smoothly and consistently, typically within a range of +/- 550 degrees. If it jumps, freezes, or shows erratic values, the problem is in the SAS circuit. Using an oscilloscope on the signal wire is the best way to see small, fast dropouts.
4. Gain access to the steering angle sensor at the base of the steering column inside the cabin by removing the lower dash/knee bolster panels.
5. Physically inspect the sensor's electrical connector. Check if it is loose or has any visible damage. Wiggle the connector to see if it has excessive up-and-down play.
6. Disconnect the connector. Inspect the male and female terminals for signs of fretting (tiny black/dark dust) or corrosion. A magnifying glass may be helpful.
7. Following TSB PI0639C, add a shim (such as adhesive foam or a piece of zip-tie) to the flat surface of the male connector body to ensure a tight, wiggle-free fit.
8. Clean the terminals with a dedicated, clean nylon brush and apply a small amount of dielectric grease (GM P/N 12377900) to both sides of the connector.
9. Reconnect the sensor, clear the codes, and test drive the vehicle, turning the wheel to see if the 'Service StabiliTrak' message returns.
10. If the code persists after securing the connector, the TSB suggests replacing the harness-side connector pigtail as the next step.
11. If the connector and pigtail are confirmed good and the code still returns, the sensor itself is the next likely culprit and should be replaced.
12. After replacing the sensor, a steering angle sensor calibration must be performed using a compatible scan tool. This is often found in the EBCM special functions menu.

Parts You'll Likely Need

• Steering Angle Sensor (OEM #20910871) — This is the part that fails if the connector repair does not solve the issue. It provides the steering wheel position data to the StabiliTrak system. Part number 19418403 is a later revision that also works.
  Trusted brands: ACDelco, Dorman
  OEM price range: $80-$150
  Aftermarket price range: $60-$120
• Dielectric Grease (OEM #12377900) — Required by TSB PI0639C to protect the electrical connector terminals from moisture and fretting corrosion, which is a primary cause of this code.
  Trusted brands: Permatex, ACDelco
  OEM price range: $15-$25
  Aftermarket price range: $5-$10
• Adhesive Back Shim Stock (OEM #P40100 (Kent Automotive)) — Specifically called for in TSB PI0639C to add to the connector body to eliminate excessive movement that leads to fretting corrosion. A small piece of foam or a zip tie can be used as a DIY alternative.
  Trusted brands: Kent Automotive
  OEM price range: $10-$20
  Aftermarket price range: $5

Related Codes That Often Appear With This One

• C0455 — This code for 'Steering Assist Control Actuator Circuit' is often listed alongside C0710 in the same TSB (PI0639C) as having the same root cause: the faulty steering angle sensor connector.
• U2143 — This code indicates 'Lost Communication With Steering Angle Sensor Module' and can appear with C0710 when the connection is poor or the sensor fails completely. A user with a similar GM vehicle reported having both C0710 and U2143, which persisted after replacing the sensor and EBCM, indicating a wiring issue between the modules.

Technical Service Bulletins (TSBs) & Recalls

• PI0639C: Addresses a 'Service StabiliTrak' message with DTC C0710 by inspecting and securing the steering angle sensor connector with adhesive shim stock (Kent Automotive P/N P40100) and dielectric grease. It explicitly warns against replacing the sensor as the first step.

Platform-Specific Known Issues

• TSB PI0639C Connector Fretting: A known issue documented in GM TSB #PI0639C is a poor connection at the steering angle sensor due to excessive clearance and fretting corrosion. This causes high resistance and signal loss, triggering the C0710 code and a 'Service StabiliTrak' message. The official fix is to add adhesive shim stock and dielectric lubricant to the connector, not to replace the sensor.

Mechanic-Grade Diagnostic Values

• 5-Volt Reference Circuit Voltage — expected: 4.8 - 5.2 Volts between the sensor's 5V reference pin and ground.. Failure: Voltage outside this range points to a wiring issue or a fault in the EBCM.
• Analog Signal Voltage (Wheels Straight) — expected: Approximately 2.5 Volts on the primary signal wire with the steering wheel centered.. Failure: A reading that is significantly different, fixed, or does not change smoothly when turning the wheel indicates a faulty sensor.
• Low Reference Circuit Resistance — expected: Less than 1.0 Ohm between the sensor's low reference (ground) pin and a known good chassis ground.. Failure: Resistance higher than 1.0 Ohm indicates a poor ground connection, which can cause erratic sensor readings.
• Sensor Internal Resistance Sweep — expected: A smooth change in resistance under 12,000 ohms (12 kOhms) when turning the steering wheel lock-to-lock.. Failure: If the ohmmeter shows an open circuit (OL) or a value exceeding 12,000 ohms at any point, the sensor's internal potentiometer track is worn out and the sensor needs replacement.

Hidden / Shadow Codes Worth Checking

• C0710-5A: Steering Position Signal Plausibility Failure. This indicates the signal received is outside the expected range or doesn't logically match other vehicle sensor inputs (like yaw rate). (see via Professional scan tools like the GM Tech II or Bosch ADS 625 will display this symptom byte, which provides more specific diagnostic direction than the base code alone.)
• C0710-42: Steering Wheel Angle Signal Calibration Not Programmed. This specifically points to a lost calibration as the root cause. (see via Visible on professional scan tools. If this code is present, performing the calibration procedure is the correct first step.)
• C0710 0F / 17 / 55: These are other symptom bytes indicating Signal Erratic, Shape/Waveform Failure, or Expected Number of Transitions not Reached, respectively. All point to an issue with the signal integrity from the sensor. (see via Displayed in the EBCM data on a Tech II or GDS2 scan tool.)

Scan Tool Commands That Help

• GM Tech II / GDS2 / Professional Scan Tool: Steering Wheel Angle Sensor Learn / Calibration — This function must be performed after replacing the steering angle sensor, after a wheel alignment, or if DTC C0710-42 is present. It is found under the 'Special Functions' menu for the Electronic Brake Control Module (EBCM). The procedure requires centering the steering wheel and following on-screen prompts to set the sensor's zero position.

Wiring & Ground Locations

• Steering Angle Sensor Connector — At the base of the steering column, accessible after removing the driver's side lower dash/knee bolster panel.. This is the primary point of failure according to TSB PI0639C. Fretting corrosion and looseness at this connector directly cause signal loss and trigger C0710.
• EBCM Ground — Typically located on the frame rail below the driver's door area, shared with other components. It's a large gauge wire bolted directly to the frame.. A poor ground for the Electronic Brake Control Module (EBCM) can cause a host of issues, including the inability to correctly process the signal from the steering angle sensor. If sensor-side voltages and grounds test good, the EBCM ground should be inspected, cleaned, and tightened.

Real Owner Repair Stories

• Tahoe Yukon Forum user (GM SUV (similar platform)) — Service StabiliTrak and traction control lights on, code C0710 present.
  ❌ Tried (didn't work) Multiple visits to the dealership could not identify the cause.
  ✅ What actually fixed it The owner had gotten a nail in a tire and replaced it with a used, mismatched tire, causing the truck to pull to one side. After replacing all four tires with a new matching set and getting an alignment, the pulling stopped and the C0710 code did not return.
• Tahoe Yukon Forum user (GM SUV (similar platform)) — Service StabiliTrak light with code C0710.
  ❌ Tried (didn't work) Initial diagnosis pointed to the sensor.
  ✅ What actually fixed it A different technician discovered that after a previous rack and pinion replacement, the steering shaft was installed one full turn off. The fix was to disconnect the steering shaft under the hood, mechanically center it to match the wheels, and then perform a sensor calibration.

OEM Part Supersession History

• 20910871 → 19418403 — Standard part revision and update by GM.
  Heads up: The parts are directly interchangeable. No incompatibilities have been noted; both are considered genuine GM parts for this application.