To what extent does it signify the need to service the trailer brake system? Your trailer has a set of brakes known as the service trailer braking system.
These brakes allow you to regulate the trailer’s speed more effectively and stop it when necessary; when you are behind the wheel of a vehicle pulling a big load, having a system that can assist in maintaining the safety of you and your loved ones is essential.
The service trailer brake system can lose its engagement for various reasons, such as if the tow vehicle and trailer are separated. If this occurs, it is essential to be familiar with the correct procedure for resetting the system so that you may continue securely pulling your trailer.
This article will explain what the warning “service trailer brake system” means, what caused it, and how you can quickly correct this issue.
This article also addresses some issues you may have about the brakes on your trailer and gives solutions to those problems.
Let’s get started!
Service Trailer Brake System GMC

A “Service Trailer Brake System” error notice, as described in the 2015 GMC Sierra owner’s handbook, indicates a problem with the trailer brake module or wiring, preventing power from transferring to the trailer’s brakes.
You may continue driving with this error notice displayed, but you shouldn’t tow anything until it is corrected. You’ll need to take the trailer to the dealer for maintenance since third-party support for the factory-integrated trailer brake controller is limited.
Unfortunately, I cannot think of a method to turn off the warning.
Instead of using the factory-installed trailer brake controller, which may be costly to repair and troubleshoot, you should install an aftermarket brake controller to provide superior performance. The Redarc Tow-Pro Elite Trailer Brake Controller (SKU: RED44FR) is an excellent choice for this purpose.
The Tow-Pro Elite works like a factory trailer brake controller, with a hidden control box and an external knob fitted at the driver’s discretion. You may place it almost anywhere, and it will have a sleek, professional appearance.
The Tow-Pro Elite is superior to the standard trailer brake controller since it allows you to convert between a proportional and a user-controlled mode. In addition, most factory-integrated trailer brake controllers don’t support electric over hydraulic trailer brakes; however, this one does.
Chevy Service Trailer Brake System
Chevy service trailer brake system is a symptom of a fault impeding the power supply from the tow truck to the trailer with the wiring or module for the trailer’s brakes. You may notice a few additional symptoms besides the error message if this occurs.
Even when the service trailer brake error notice is shown, it is still possible to drive the vehicle. You are strongly encouraged to refrain from towing any weight until the issue has been resolved.
If you do not take action to remedy the problem, your brakes might sustain further damage over time, which could result in unanticipated accidents.
When you least anticipate it, even a little mistake might result in significant consequences, such as an accident. Therefore, it is in your best interest to address any problem you discover in your car until you are certain the issue has been resolved.
Therefore, even though it is feasible to drive with an error warning shown on the trailer brake controller, doing so is neither safe nor desirable.
At no point may safety be compromised in any way. Therefore, the fact that a vehicle continues to travel while having a problem does not always suggest that everything is OK.
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How To Reset The Service Trailer Brake Message

It is not an overly difficult task to learn how to reset the service trailer braking system when you have the proper training. However, the procedure calls for the use of a few different instruments.
You will need a flathead screwdriver, a piece of solid wood or rock, a powerful hammer, and perhaps assistance to help make the process easier for you.
As soon as you have these resources at your disposal, you can instantly start the process of resetting the password.
To begin, you will need to assemble the following supplies:
- A screwdriver with a flat head
- A hammer
- A hunk of lumber or a solid rock
- An assistant (optional)
You can reset your vehicle’s trailer brake controller system by following the method outlined in the following steps.
- Locate the nut that adjusts the brakes on the trailer.
The first thing you need to do is locate the adjustment nut, which is located directly on the rear of the trailer brake on the truck. Typically, it is located near the axle. After you have found this component, you are ready to go on to the next stage.
- Use a screwdriver to loosen the locknut on the nut.
A nut for adjusting the tension with a corresponding locknut on the trailer brake for securing it. First, obtain the screwdriver with the flat head, and then use it to loosen this nut. Because of this, the following assignment will be much simpler for you to do.
- Adjust the tension by rotating the nut counterclockwise.
After you have successfully loosened the lock nut and the adjustment nut has been released, move the adjustment nut clockwise very gently until it is tight against the backing plate of the component.
However, as you adjust the nut, you must be careful not to overtighten it to prevent any issues.
Meanwhile, if the previous solution does not fix the issue, you most likely have an issue with the trailer’s braking system. As a result, you may need to purchase a whole new replacement for the component.
Servicing Your Trailer Brake

Follow the below steps for servicing your trailer brake:
- Check the fuse associated with the problem, and if it’s blown, replace it.
- It is important to clean all of the connections on the trailer, including the TBCM connectors.
- After applying some dielectric grease to the primary trailer harness, confirming that the connections are secure, and then plugging in the trailer again.
- Replace the relay on the frame rail behind the driver’s seat, near the rear axle.
- Finally, the relay assembly should be replaced.
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What Does Service Trailer Brake System Mean?
The error message for the service trailer brake system is a warning signal that indicates a disengagement of a trailer from the vehicle that is towing it, which means that the trailer can no longer receive power from the vehicle required for it to operate.
So, in case you were wondering, “What exactly does it imply when someone says a service trailer braking system?”
It is a symptom that there is a problem with the wiring or module of the trailer brakes, preventing power from being sent from the tow vehicle to the trailer. If this occurs, in addition to the error notice, it will exhibit a few additional symptoms.
A delay in the process of stopping the trailer, a harsh noise coming from the brake, a sinking pedal, and an abrupt lack of responsiveness or mushy sensation when you activate the trailer brake are some of the indicators that may appear.
Be sure to reset the trailer brake as soon as possible if you are experiencing any of the issues described above or at least seeing the service trailer brake controller error message. It will prevent the problem from worsening, resulting in an unforeseen accident or damage.
Frequently Asked Questions
1. Why Does My Truck Keep Saying Service Trailer Brake System?
If the message “service trailer brake system” keeps appearing on your dashboard, it indicates that a trailer has been disconnected from the car pulling it. In addition, it indicates that the trailer can no longer receive electricity from the vehicle, which is necessary for it to function.
It is a symptom that there is a problem with the wiring or module of the trailer brakes, preventing power from being sent from the tow vehicle to the trailer. If this occurs, in addition to the error notice, it will exhibit a few additional symptoms.
2. How To Turn Off Service Trailer Brake System
Unplugging your brake controller would be the quickest and simplest solution to this problem. If the brake controller is removed, the brakes will no longer receive power.
If your brake controller is hardwired and cannot be disconnected, you may cut the brake output cable between the brake controller and the trailer brakes. If your brake controller was not hardwired, you could unhook it from the controller.
3. How Often Should I Service My Trailer Brakes?
Regular inspection is the most effective method for ensuring that your brakes remain in good working order. Brake inspections should be performed at least once a year or after a distance of 12,000 miles.
If you don’t use your trailer very frequently, you should specifically be sure to examine it regularly. Examine each component of the system, beginning with the vehicle you use for towing and working your way back to the trailer, looking for any indications of wear and tear or dysfunction.
It entails inspecting any hardware and looking at the shoes, drums, and return springs. In addition, it is recommended that you take your trailer out for a spin at least once every three months to verify that all of its components are working.