C0455 on 2013-2016 GMC Savana: Steering Angle Sensor Circuit Fault & Fixes

What's Unique About the 2013-2016 Gmc SAVANA

On this generation of GMC Savana and its platform-mate, the Chevrolet Express, the C0455 code is overwhelmingly caused by a known design issue with the steering angle sensor's electrical connector. GM issued a Technical Service Bulletin (TSB #PI0639C) acknowledging that excessive clearance and fretting corrosion in the connector—not sensor failure—is the root cause. This makes checking the connector the mandatory first step, which can save owners hundreds of dollars by avoiding an unnecessary sensor replacement.

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 displayed on the Driver Information Center (DIC)
• "Service Traction Control" message displayed on the DIC
• StabiliTrak/Traction Control indicator light is illuminated
• StabiliTrak and Traction Control systems are disabled
• In rare, severe cases, the ABS can trigger and lock up the brakes, making the vehicle undriveable.

Most Likely Causes

1. Loose or Corroded Steering Angle Sensor Connector 🔴 High Probability → Shop Steering Angle Sensor A known issue documented by GM in TSB #PI0639C. The plastic connector housing has excessive clearance, leading to movement, vibration, and fretting corrosion on the terminals, which interrupts the signal. Fretting corrosion appears as small, dark smudges on the electrical terminals.
   How to confirm: Visually inspect the steering angle sensor connector for looseness or signs of dark smudges (fretting corrosion) on the terminals. The connection may feel sloppy. A scan tool can confirm the C0455 code is present.
   Typical fix: Apply the official TSB fix: add an adhesive shim to the flat surface of the male connector to eliminate movement, clean the terminals with a dedicated nylon brush, and apply a small amount of dielectric lubricant before reconnecting.
   Est. part cost: $15-$30

Rare But Worth Checking

• Failed Steering Angle Sensor: → Shop Steering Angle Sensor While much less common than the connector issue, the sensor itself can fail. This should only be considered after the TSB fix for the connector has been properly attempted and the code returns. Some owners have replaced the sensor multiple times only to have the light reappear, pointing back to the connector or wiring.
• Improper Steering Wheel Alignment/Installation: If the steering wheel or intermediate shaft was recently removed and not reinstalled correctly (e.g., off by 360 degrees), it can trigger this code. A steering angle sensor recalibration with a scan tool is required after such repairs.
🎬 Watch: How to reset and calibrate the steering angle sensor
• Wiring Harness Damage: Damage to the wires leading to the steering angle sensor can cause an open or short circuit, triggering the code. This is unlikely without other signs of damage under the dash. The TSB notes that if the shim fix fails, the next step is to replace the harness-side connector pigtail.
• Poor Ground Connection: On related GM platforms, owners have reported that cleaning and securing chassis and engine bay ground points can sometimes resolve intermittent StabiliTrak issues.

Diagnosis Steps

1. Confirm the presence of code C0455 (and possibly C0710) using an OBD-II scanner capable of reading chassis (C-prefix) codes.
2. Gain access to the steering angle sensor, which is located on the steering column under the dashboard, near the intermediate shaft.
3. Disconnect the sensor's electrical connector.
4. Inspect the connector terminals on both the harness and sensor side for looseness and fretting corrosion (dark smudges). A magnifying glass may be needed to see minor corrosion.
5. If looseness or corrosion is suspected, perform the TSB #PI0639C repair: 🎬 Watch: A quick tip on applying the TSB shim fix apply a piece of adhesive shim stock (like Kent Automotive P40100) to the flat surface of the male connector to tighten the fit.
6. Using a dedicated, clean nylon brush, clean the terminals and apply a small amount of dielectric lubricant (like GM 12377900) to both sides of the connector. Do not over-apply, as this can cause hydrolock.
7. Reconnect the connector securely. The shim should make the connection much tighter.
8. Clear the DTCs with the scan tool. Turn the ignition off for at least 10 seconds, then start the vehicle and turn the steering wheel lock-to-lock to see if the code returns.
9. If the code returns immediately, a more advanced diagnosis is needed. This may involve using a scan tool to monitor the sensor's live data (Phase A, Phase B, and angle degrees) while turning the wheel to check for signal dropouts.
10. If the TSB fix fails and the wiring is confirmed to be good, the harness-side connector pigtail may need to be replaced.
11. If the sensor is confirmed to be faulty, it will need to be replaced, which may require steering column disassembly and subsequent recalibration.

Parts You'll Likely Need

• Steering Angle Sensor Connector Shim & Dielectric Lubricant (OEM #Kent Automotive P40100 (Shim Stock), GM 12377900 (Lubricant)) — This is the official, most common fix recommended by GM's TSB to correct the loose connector that causes the code.
  Trusted brands: Kent Automotive, ACDelco
  OEM price range: $15-$30
  Aftermarket price range: $10-$20
• Steering Angle Sensor (OEM #ACDelco 23483397 (Verify by VIN)) — This part is only needed if the connector fix fails and the sensor is diagnosed as faulty. 🎬 See this walkthrough for replacing the steering wheel position sensor It is often replaced unnecessarily.
  Trusted brands: ACDelco (GM Genuine), Dorman (e.g., 601-230)
  OEM price range: $100-$180
  Aftermarket price range: $60-$120

Related Codes That Often Appear With This One

• C0710 — This code is also related to the steering angle sensor and is often set alongside C0455 for the same root cause, as noted in GM's TSB #PI0639C.

Technical Service Bulletins (TSBs) & Recalls

• PI0639C: 'Service Stabilitrak Message Displayed in DIC, DTC C0455 or C0710 Set'. This bulletin details the primary cause as a poor connector fit and outlines the repair using shim stock and dielectric grease, explicitly warning not to replace the sensor for this condition. It covers a wide range of GM trucks and vans, including the 2008-2016 Savana.

Platform-Specific Known Issues

• The primary issue for this vehicle is the poor fit of the steering angle sensor connector, as documented in TSB #PI0639C, which applies directly to the 2008-2016 GMC Savana.
• Owner experiences confirm that simply replacing the sensor, even with an OEM part, often does not fix the issue if the underlying connector problem is not addressed first.

Mechanic-Grade Diagnostic Values

• Scan Tool Live Data: Steering Wheel Angle — expected: Near 0° when the steering wheel is centered and front wheels are pointed straight ahead. The value should change smoothly and correlate with steering wheel rotation.. Failure: The value is stuck, jumps erratically, shows a large angle (e.g., 360°) when centered, or does not change when the wheel is turned.
• Scan Tool Live Data: Digital Signals (Phase A, Phase B, Marker Pulse) — expected: Phase A and Phase B are digital square wave signals that should toggle between High and Low as the wheel is turned. The Marker Pulse should be HIGH when the wheel is centered (approx. +/- 10 degrees) and LOW otherwise.. Failure: One or more signals are stuck high or low, or do not change state as the steering wheel is rotated.

Hidden / Shadow Codes Worth Checking

• C0455 5A: Indicates a 'Steering Wheel Angle Sensor Signal Plausibility Failure'. This symptom byte suggests the signal is present but not logical, which can occur after software updates to other modules create a conflict. (see via A professional GM scan tool like a Tech2 or GDS2 is required to view these two-digit symptom bytes.)

Scan Tool Commands That Help

• GDS2 / Tech2: Steering Angle Sensor Learn / Calibration — This function must be performed after replacing the steering angle sensor, the EBCM, or after any steering or suspension repair (including wheel alignment) that could alter the steering wheel's center position. Failure to perform this calibration will cause code C0455 to persist.

Wiring & Ground Locations

• Steering Angle Sensor Connector — On the steering column, under the driver's side dashboard, typically with 5 wires.. This is the primary point of failure due to looseness and fretting corrosion, as identified in TSB PI0639C.
• G302 — Behind the left kick panel, under the driver's side dash.. This is a major instrument panel ground splice pack. A poor connection here can cause a variety of intermittent electrical issues, including loss of communication or erratic data from modules like the steering angle sensor that communicate through the BCM.

Real Owner Repair Stories

• GMTNation Forum (GMC Envoy (related platform with same issue)) — 'Service Stabilitrac' message and C0455 code.
  ❌ Tried (didn't work) Replaced the steering angle sensor with a Dorman part., Replaced the Dorman sensor with an OEM ACDelco sensor.
  ✅ What actually fixed it The code returned immediately after both sensor replacements. The underlying issue was the wiring/connector itself, pointing back to the problem described in the TSB where the sensor is not the root cause.
• TSB PI0639D (2008-2016 GMC Savana) — Service Stabilitrak message, DTC C0455 and/or C0710.
  ❌ Tried (didn't work) Replacing the steering angle sensor (explicitly advised against in the TSB for this condition).
  ✅ What actually fixed it If the shim and dielectric grease fix does not resolve the issue, the TSB instructs technicians to replace the steering angle sensor harness-side connector with a service pigtail. This indicates the terminals in the original connector can become too damaged or worn for the shim to be effective.

OEM Part Supersession History

• 19330423 (and others) → ACDelco 23483397 — Standard part updates and consolidation.
  Heads up: The connector design on the sensor itself did not change, which is why the TSB (PI0639C/D) applies to vehicles across a wide model year range, even if the sensor part number was updated. The fault lies with the harness-side connector, not the sensor-side.