The “Service Stabilitrak” message in a GMC Terrain signals a problem with the vehicle’s stability control system.
Common causes include faulty sensors, damaged wiring, or issues with the control module.
In my experience, “Service Stabilitrak” is most often caused by a bad wheel speed sensor in the Terrain.
GMC Terrain Diagnostic Table
The number one reason that the StabiliTrak system fails is a wheel speed sensor issue.
| Possible Cause | Description & Suggested Action |
|---|---|
| Wheel Speed Sensors | Faulty sensors can send incorrect signals to the StabiliTrak system. Action: Inspect and replace faulty wheel speed sensors. |
| Steering Angle Sensor | Malfunctioning sensor affects the system’s ability to gauge steering input. Action: Check and recalibrate or replace the steering angle sensor. |
| Brake System Issues | Problems with the brakes can interfere with the StabiliTrak system. Action: Inspect the brake system, including pads, rotors, and fluid levels. |
| Engine Control Module (ECM) | Issues with the ECM can affect various systems, including StabiliTrak. Action: Diagnostic scan to check for ECM-related error codes and address them. |
| Poor Electrical Connections | Loose or corroded connections can disrupt system communication. Action: Inspect and clean or tighten electrical connections. |
| Software Glitches | Sometimes, the system may need a reset or software update. Action: A reset or update of the vehicle’s computer system may be required. |
How The Stabilitrak System Works in the GMC Terrain
Stabilitrak Components
Stabilitrak is a sophisticated electronic stability control system designed to enhance your GMC Terrain’s stability, especially in emergency situations. Here’s how it achieves this:
- Wheel Speed Sensors: These are located on each wheel hub and monitor the rotational speed of each wheel. This helps in detecting differences in wheel speed, which could indicate slipping or loss of traction.
- Rotation Rate Sensor: Positioned to measure the vehicle’s lateral movement and rotation around its centerline. This sensor is crucial in identifying when your Terrain is veering off its intended path.
- Steering Wheel Position Sensor: This tracks the angle and rate at which the steering wheel is turned, providing real-time data on driver inputs.
- Control Unit: The brain of the system, it processes data from all sensors to determine when to activate StabiliTrak. In certain scenarios, it can instruct the powertrain control module to reduce engine power, aiding in regaining control.
- Hydraulic System: Integrated with the ABS (Anti-lock Braking System), it can independently apply brakes to each wheel, crucial in reorienting the vehicle correctly.
Application of the System
The system’s control unit uses sensor data to execute precise actions, like applying brakes to specific wheels or reducing engine power.
This is vital for correcting slides and maintaining the intended direction of the vehicle.
For instance, if your Terrain starts sliding on ice, Stabilitrak might activate one of the rear brakes to realign the vehicle. To see Stabilitrak in action, GM provides a detailed video demonstrating its functionality in various scenarios.
Overall, understanding how Stabilitrak works enhances your appreciation of the safety features in your GMC Terrain, showcasing the advanced technology that helps keep you safe on the road.
Here’s a video from GM that shows precisely how the system works.
Service StabiliTrak Symptoms: GMC Terrain
1. Stabilitrak Doesn’t Kick on Unless There’s An Emergency
- Normal Driving: In everyday driving, you won’t notice the StabiliTrak system. It’s designed to be unobtrusive.
- System Engagement: StabiliTrak kicks in when your Terrain isn’t following your steering direction or if it detects an overcorrected skid. You’ll likely feel it when it engages.
2. Service StabiliTrak Warning (Primary Symptom)
- Main Indicator: The “Service StabiliTrak” warning light is the primary sign that there’s an issue with the system. It’s a clear alert to check the system.
3. Impact on Cruise Control
- Wheel Speed Sensors: If these sensors malfunction, your Terrain might lose cruise control functionality. This is because cruise control relies on accurate wheel speed data.
4. Traction Control System Issues
- Functionality: The traction control system, which prevents wheel spin, shares sensors with StabiliTrak.
- Warning Messages: A malfunction might trigger both “service traction control” and “Service StabiliTrak” messages. Unlike StabiliTrak, which addresses sliding issues, traction control manages wheel spin during acceleration.
Addressing the “Service StabiliTrak” warning is crucial for maintaining the safety and performance of your GMC Terrain, especially in challenging driving conditions.
GMC Terrain: Service StabiliTrak Light Causes
Many things can cause the StabiliTrak system to lose its ability to function, but the most common one is a wheel speed sensor. A good scanner should tell you which system has failed and is worth its weight in gold if you’re trying to fix your Terrain’s StabiliTrak system.
The steering wheel sensor is a common reason older Terrain’s get the Service StabiliTrak warning.
Wheel Speed Sensor
Wheel speed sensors are the number one reason that the StabiliTrak system fails.
If one of the wheel speed sensors is having issues, your Terrain will no longer be able to tell if all wheels are turning at the same speed. Without this data, the “Service StabiliTrak” warning will turn on.
Wheel speed sensors are exposed to road debris, mud, and salt. This can cause them to fail or their wiring harness to short out.
One telltale sign that the wiring harness to one of the front wheels is failing is the Service Stabilitrak warning when turning your Terrain to the left or right. This is because the harness moves a little while you turn, which can cause the wheel speed sensor to connect and disconnect intermittently.
Brake Pedal Switch
Your Terrain’s brake pedal switch does more than just control whether or not your brake lights are turned on. The ECU and StabiliTrak control units use this switch to know when you’re hitting the brakes. If the switch isn’t functioning correctly, these systems may be disabled.
Faulty Stability Control Module
The Stability Control Module is your Terrain’s computer that controls the StabiliTrak system. It may have failed or needs to be reset.
Wrong Tire Size
StabiliTrak may not work correctly if the tire size is not what GM calls for your model Terrain.
Many other less likely issues can cause the StabiliTrak system to stop working as well. It’s a good idea to test and see if you have any trouble codes. They may provide you with clues that’ll help you fix it.
Resetting the StabiliTrak System in Your GMC Terrain
Basic Reset Procedure
- Power Down: Turn off your vehicle and wait for about 15 seconds. This brief period allows the StabiliTrak system to reset.
- Restart: After powering back up, check if the system works. If it does, you’re good to go!
When to Seek Service
- Persistent Issues: If the problem continues after the reset, it’s time to get professional service.
- Engine Light and Warning: Alongside the “Service StabiliTrak” warning, you might see the “service engine soon” light. This often means there are diagnostic codes related to the traction control system.
Conclusion
Although it may be tempting to ignore the Service StabiliTrak warning, it can be dangerous not having the system available when needed.
While driving your GMC Terrain without traction control or StabiliTrak won’t cause a breakdown, you are operating your vehicle without an important safety feature.