Service Trailer Brake System

Understanding Service Trailer Brake System

There are numerous warning messages on your dashboard that might alert you to potential issues. The message “Service Trailer Brake System” is one such warning that you could see. You should maintain your trailer brake system if you always tow a trailer with your truck. It must operate without error for your safety.

Service Trailer Brake System

The “service trailer brake system” message on your dashboard signals an issue with the system’s or module’s electrical wiring, which prevents power from the vehicle from reaching the trailer. Well, in this article, we’ll get to discuss the answers to the following questions:

  • What is a trailer brake?
  • What does the service trailer brake system message mean?
  • Can you drive with the service trailer brake system message on?
  • What causes the service trailer Brake system to come on?
  • How do you reset the service trailer brake system?
  • What’s the cost of fixing a trailer brake system?
  • How often should you service the trailer brake system?


Ok then, let’s get down to business.


What is a trailer brake?

The trailer brake controller system of a vehicle is an OEM or aftermarket module or device fitted on the vehicle to assist the driver in controlling the trailer’s speed as well as stopping. The device is mounted to the tow vehicle’s dashboard on the driver’s side. When reducing speed to stop, the trailer brake controller system is intended to activate directly in proportion to the tow vehicle’s brake or at a time-delayed frequency. A plus/minus adjustment gain is installed in the majority of vehicle trailer brake systems. A brake system of many different types can be installed on the trailer. A system that works with enclosed trailers, campers, horse trailers, and boat trailers is simple to operate.

What does the “service trailer brake system” message mean?

The “Service Trailer Brake System” message informs you that the trailer brake system has disengaged due to wiring issues or some other problem. The brake system may be hampered if the trailer being towed doesn’t have enough power. In addition to the warning, there can be further symptoms. The problem may make it difficult to stop the trailer. When you brake, odd noises can also be heard. There can be issues with the lighting and other devices on the trailer if there isn’t enough power.

Can you drive with the service trailer brake system message on?

Driving a car with the service trailer brake warning message may be possible. However, until the issue is resolved, you must refrain from towing any loads. Failure to address the problem could endanger your brake in the long run and cause unanticipated collisions. As a result, even though it is technically feasible to drive with the trailer brake controller warning message, doing so is not recommended or safe.

At all times, safety must be ensured. Therefore, just because a vehicle moves in spite of a problem does not mean everything is fine. Unexpectedly, a minor error can result in serious harm or an accident. It is therefore essential to fix any problems you find with your car till you are certain that they are resolved.

What causes the service trailer Brake system to come on?

What causes the service trailer Brake system to come on?

Here are the most common causes of service trailer brake system messages:

Blown Fuse

The most common and possible reason why your service trailer brake system message illuminates is due to a blown FUSE. A fuse controls the power of every electronic component in your car. Nevertheless, the fuse could blow if the system receives too much voltage. In some scenarios, a blown fuse signals the possibility of a bigger issue, which is simple to identify if the problem reappears after replacing the fuse. Check the owner’s manual for your automobile to find the proper fuse, then examine if it has blown. If so, swap it out for a similar fuse to resume driving.

Defective Master Brake Cylinder/Sensor

Another possible cause of this message is either a defective master cylinder or sensor. A master cylinder and a few sensors are used in the brake system to make sure everything is working properly. The message may become visible when something goes wrong. This message may occasionally appear alongside others, signaling the presence of a more serious brake issue. You may be required to pay a higher repair fee depending on which sensor failed.

Faulty Brake Light Switch

The warning could be illuminated if the brake light switch malfunctions. The good news is that it is typically inexpensive to replace this component. In most car models, the brake light switch is positioned on the brake pedal, and changing it yourself is frequently relatively simple. But you must make sure that the switch is adjusted properly afterward.

Faulty/broken Trailer Brake Control Switch

In most car models with a trailer brake system, you often see a trailer brake controller behind the dashboard. This control switch for the trailer brakes may malfunction, necessitating replacement. Additionally, the connectors can be tainted or unclean. A broken trailer brake controller switch under your steering wheel is a relatively typical component that causes the Service Trailer Brake System warning message to appear on a Chevrolet.

Damaged/Faulty Wiring

Wiring problems could also be the reason why the service trailer brake system warning message comes on. The signals cannot be sent where they need to go when the wires get tattered or broken. The brake system warning appears on the dashboard as a result of this malfunction. If you aren’t experienced at locating electrical problems, a professional could be better suited to do this job. Before any connections or wires can be fixed, they must be examined for damage.

Differences between surge brakes and electric trailer brakes?

Surge brakes

This type of trailer brakes is a hydraulic self-contained braking system. Utilizing the weight of the trailer itself, the brakes are applied to reduce motion. With this type of non-electric trailer brake system, a hydraulic cylinder is compressed and pressure is transferred to the trailer brakes, slowing down the trailer when you apply the brakes to the car to slow it down.

Electric trailer brakes

In this type of trailer brakes, the vehicle is towed by electrical power. Electromagnetic brake drums are activated by an electric trailer brake system that electrically connects to the tow. The ability to willingly apply the brakes is then in the driver’s hands. The tow vehicle also has to have a trailer brake controller in order for an electric trailer brake system to function.

How do you reset the service trailer brake system?

In order to reset the service trailer brake system, you’ll need a flathead screwdriver, hammer, piece of wood or rock, and assistant (optional). Here’s how to reset a service trailer brake system:

  • Find the adjustment nut on the trailer brakes’ backside. This is typically seen close to the axle.
  • Loosen the locknut holding the adjustment nut in place with the flathead screwdriver.
  • When the adjusting nut is snug against the backing plate, turn it clockwise. Avoid over-tightening.

Read more: Traction control light: meaning, causes, and how to reset

What’s the cost of fixing the trailer brake system?

A service trailer brake system repair is estimated to cost about $300. This price includes all components, labor, and installation work. The type of trailer brake controller used and the mechanic performing the work can, however, affect the price of replacing the service trailer brake system. As a result, in any situation, make sure to make a budget and include the cost of repairing the trailer brake system in the budget. No matter how much it costs, the whole repair for a GMC Sierra’s service trailer brake system won’t break the bank.

How often should you service a trailer brake system?

Generally speaking, you should service your trailer brakes once a year or every 12,000 miles, whichever comes first. However, you might need to service the brakes more frequently if you use your trailer more often or over long distances. Keep an eye out for any indications that the brakes require maintenance and be mindful of how frequently you use your trailer. You can make sure that your trailer brakes are always in good operating order by keeping up with maintenance.

Watch the video below to learn how to fix the Trailer Brake System of your vehicle:


What does it mean when my truck says service brake system?

Your brake pads need to be replaced because they are worn out.

What is the trailer service brake?

Every time the brake pedal is depressed, the trailer service brakes will engage. The towing vehicle frequently has a hand valve installed on the steering wheel or instrument panel so the driver can use the trailer service brakes independently of the towing vehicle’s brakes.

How do you reset trailer brakes?

Placing the pin back into the switch is all that is required to restart a breakaway system if your brakes are electric. Once the brakes are released, the trailer can roll freely.

Why does my trailer brake light keep coming on?

The brake light circuit appears to be constantly powered by what sounds like a fault in the wiring of your car or trailer. We recommend first inspecting the connector on both the vehicle side and the trailer side, checking the pins for rust or buildup, and then only cleaning if necessary.

How do you check trailer brakes?

To do this test, all that is necessary is to set the compass close to the brakes, supply electric current to them via the controller, and observe whether or not the compass moves. If the compass isn’t moving, the magnets aren’t receiving current, then your controller or wiring may be malfunctioning.

Is there a fuse for trailer brake lights?

If the turn signals were the issue, then simply check for and replace the trailer RT or LT fuse as required. Since that they use the same fuse, this will also solve the problems with the brake lights.

Where is the brake fuse located?

The power distribution center, which is either located behind the hood or under the dashboard, is where you’ll find the brake light system fuse, as well as all other fuses. The power distribution center, you’ve never heard of it? It is simply a fuse box’s technical name.

Can I drive with a brake system warning light?

Any fault with the brake system must be considered a serious safety concern, and your vehicle shouldn’t be driven until the issue has been fixed by a professional.

How do you service a brake system?

  • Maintain the proper levels of brake fluid by checking it frequently.
  • Examine the brake lines.
  • Change the brake fluid.
  • Examine the brake pads on your car, and if necessary, replace or upgrade them.

Related Article

That is all for this article where we discussed the answers to the following questions:

  • What is a trailer brake?
  • What does the service trailer brake system message mean?
  • Can you drive with the service trailer brake system message on?
  • What causes the service trailer Brake system to come on?
  • How do you reset the service trailer brake system?
  • What’s the cost of fixing the trailer brake system?
  • How often should you service the trailer brake system?

I hope you learn a lot from the reading. If you do, kindly share it with others. Thanks for reading; see you around!