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.
The “Service Trailer Brake System” message on your dashboard means there’s an issue with the electrical wiring of the trailer brake or module, disrupting the power supply between the truck and the trailer.
You should maintain your trailer brake system if you always tow a trailer with your truck. It must operate without error for your safety. It also includes a breaker switch to open and close the ignition coil’s primary circuit, except for certain modern engine systems.
The reasons and causes why a service trailer brake system light comes on include a blown fuse, a faulty brake light switch, a bad master brake cylinder or sensor, a broken trailer brake control switch, and bad wiring. Learn about ABS sensors here!
Now, let’s go deep to explain what a service trailer brake system is, its warning message, reasons why its light comes on, and how to reset it!
Related: What Is VSC System? Its Function, Light And Causes
What is a trailer brake?
The trailer brake controller is a module or device installed in a vehicle to help the driver control the speed and stopping of the trailer.
Mounted on the driver’s side dashboard, it activates proportionally to the vehicle’s brake or at a time-delayed frequency when reducing speed.
Most systems have a plus/minus adjustment gain, and different types of brake systems can be installed on the trailer, making it simple to operate with enclosed trailers, campers, horse trailers, and boat trailers.
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. Insufficient power in the towed trailer may hinder the brake system. In addition to the warning, there can be further symptoms.
The problem may make it difficult to stop the trailer. You can also hear odd noises when you brake.
The “Service Trailer Brake System” warning message on your vehicle’s dashboard indicates a potential issue with the trailer brake system. This could be due to a variety of factors, including electrical connections, brake controller problems, or even issues with the trailer brake system itself.
Can you drive with the service trailer brake system message on?
You can drive a car with the warning message for the service trailer brake, but do not tow any loads until the issue is resolved. Ignoring the problem could lead to brake failure and unexpected collisions.
So, while technically possible, it is not recommended or safe to drive with the warning message from the trailer brake controller. Here are the most common causes why a service trailer brake system light comes on:
Blown Fuse:
The most common and possible cause of the illuminated service trailer brake system message is a blown fuse. A fuse controls the power of every electronic component in your car.
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.
Defective Master Brake Cylinder/Sensor:
Another possible cause of this message is either a defective master cylinder or sensor. The brake system uses a master cylinder and a few sensors to ensure proper operation.
This message may occasionally appear alongside others, signaling the presence of a more serious brake issue.
Faulty Brake Light Switch:
If the brake light switch malfunctions, it could illuminate the warning. 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. However, it’s crucial to ensure that you adjust the switch correctly afterwards.
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, tainted or unclean connectors may be present.
Bad Wiring:
Wiring issues could also trigger the warning message for the trailer brake system. When the wires become tattered or broken, the signals fail to reach their intended destination. The brake system warning appears on the dashboard as a result of this malfunction.
Related: Service StabiliTrak Light: Causes, Fix, &# Reset
What are the differences between surge brakes and electric trailer brakes?
Surge brakes
This type of trailer brake is a hydraulic self-contained braking system. The brakes use the trailer’s weight to decrease 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
This type of trailer brake uses electrical power to tow the vehicle. An electric trailer brake system, which electrically connects to the tow, activates the electromagnetic brake drums. The ability to willingly apply the brakes is then in the driver’s hands.
How do you Reset the Service Trailer Brake?
To reset the brake system for the service trailer, you’ll need a flathead screwdriver, hammer, piece of wood or rock, and an assistant (optional). Here’s how to reset a service trailer brake:
- Please locate the adjustment nut on the backside of the trailer brakes. Typically, you’ll find it near 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 overtightening.
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.
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.
Watch out for any signs that the brakes need maintenance, and pay attention to how often you use your trailer.
Related: What Is An Anti-Lock Braking System? Its Parts And How It Work
FAQs
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?
Your car or trailer’s wiring appears to be constantly powering the brake light circuit. 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, and 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 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 fuse for the brake light system, 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.