How To Fix Service Trailer Brake System?

It can be alarming if you notice a trailer hooked up on your vehicle dashboard and see that weird little service trailer brake system warning light come on the dashboard.

But in most cases, you can easily troubleshoot the problem and make some quick repairs. Here’s a guide on how to fix service trailer brake system warning.

How Does Service Trailer Brake System Work?

The system helps with braking and prevents accidents when driving a vehicle towing a heavy load such as a trailer. It ensures that the vehicle and trailer brake accordingly in the same time span so that the driver can achieve the minimum braking distance.

The yellow warning light indicates that there is a problem with the trailer brake system. It can be caused by many factors, such as faulty wiring, brake controllers, or connection issues.

Causes of Service Trailer Brake System Warning Light

The Service Trailer Brake System warning light comes on and may require a few different actions depending on the cause:

1. Bad Connection

This is the most common cause bad electrical communication between the towing vehicle and the trailer. Corrosion, dirt, or damage to the trailer plug or socket will limit or cut off the signal, triggering the warning light.

2. Wiring Problems

A damaged or frayed wire can limit the flow of information between the brake controller and its trailer brakes. Loose connectors or exposed wiring may produce intermittent signals, which in turn trigger the warning light.

3. Brake Controller Malfunctions

This warning light will illuminate if the brake controller, responsible for managing the trailer brakes, is malfunctioning due to an internal fault, incorrect settings, or some kind of calibration.

Causes of Service Trailer Brake System Warning Light

4. Brake System Problems

If the warning light comes on, it means your trailer’s brake system is malfunctioning. Maybe you have low brake fluid, worn brake pads, or a problem with one of your brake components.

5. Software Glitches

On occasion, the warning could simply be a software glitch or an electronic control unit (ECU) fault, and you don’t have a hydraulic or electronic brake system issue.

You must not overlook it if this “Service Trailer Brake System” warning light appears in your cab. It’s a safety issue related to towing that could lead to accidents or even more problems with the brake system. Inspect the brake system and call a professional to see if the system is working properly.

How To Fix Service Trailer Brake System?

Check the Connector: Perform a pre-trip inspection of the truck trailer connection. Identify any corrosion, dirt, or damage to the trailer plug and socket.

Overtighten the Connection: Make sure the connection is tight but not too tight. A loose connection can result in intermittent signals, which can lead to warnings.

1. Examine the Wiring

How To Fix Service Trailer Brake System

Visual Inspection: Visually check the wiring from the brake controller to the trailer brakes for frayed wires, loose connectors, or exposed wires. 

Repair or Replace: If some wires are damaged, such as kinked, slightly frayed, or broken, replace them with wires from another guitar.

2. Check the Brake Controller

Functionality Test: Confirm that the trailer brake controller is working appropriately. For exact test directions, please refer to the vehicle’s manual.

Recalibration: Some brake controllers may need recalibration. Follow the manufacturer’s instructions for recalibration.

3. Inspect the Trailer Brakes

Brake Pads and Rotors: Check the condition of the brake pads and rotors. If they are dangerously worn, install new components. 

Fluid Hydraulic: Check the get level of hydraulic brake fluid in trailer. Add oil if needed. 

4. Test The System

Manual Override: Brake controller manual override will command your electric brakes to stay on whenever you want them to, allowing you to put the controller through a simulated braking action.

That means you can perform a trailer brake test. With the brake and the brake controller manual, the green indicator lights are lit. Next, pull your truck out and test the trailer by braking. The brakes should engage at this point.

Road Test: After reinstalling the CB connector up there, take a brief drive to check that the red light does not appear again and that the brakes on your trailer are fully functional.

Consult a Professional

Possible Causes: If the warning stays on after you’ve done these checks, you should take the car to an auto repair specialist. They will then carry out a thorough inspection and repair. 

How To Prevent Service Trailer Brake System Warning Light?

To never again get stuck with Service Trailer Brake System warning light, consider the following preventative steps:

Regular Inspections: Periodically inspect the trailer brake system and connections.

Clean Connections: Keep the trailer plug and socket clean and free of corrosion.

Check Fluids: Regularly check and maintain the hydraulic fluid levels if applicable.

Professional Servicing: Have your trailer brake system professionally serviced at regular intervals.

FAQs On Service Trailer Brake System

What Does the “Service Trailer Brake System” Warning Mean?

Service Trailer Brake System message means the trailer braking system is not working right. The first thing that comes to mind is that the wiring between the tow vehicle and the trailer is bad or there’s something wrong with the braking controller or trailer brakes.

Can I Drive with the Service Trailer Brake System Warning Light On?

You could set off driving with the trailer brake system warning light on, but it’s not recommended! The trailer warning light comes on because the system can’t work properly. To tow safely, you need to make the system work properly, so you should address the system problem as soon as possible. 

How Can I Check the Trailer Connection For Issues?

To check the trailer connection, visually inspect the trailer plug and socket for signs of corrosion, dirt, or damage. Make sure the connection is snug and secure. Then, give it a little wiggle to see whether the warning light flickers or turns off, which would likely indicate a loose connection.

What Should I Do If the Brake Controller is Not Working?

If it’s not working, try to locate the fuse and wiring in your vehicle’s wiring diagram and check for melted or loose wires or fuses. Refer to your vehicle’s manual and/or the brake controller’s instruction manual for any specific troubleshooting instructions. Otherwise, consider recalibrating the brake controller to get it back up to speed.

When Should I Seek Professional Help?

Suppose you have attempted known troubleshooting steps (check for a tight connection to the trailer, check for wiring damage, check the brake controller, etc.), and the brake circuit warning light still illuminates. In that case, it is time to have an ASE-certified auto technician make a thorough diagnosis of the problem and repair it so your trailer’s brake system operates properly and safely. 

Conclusion

The warning above may be solved by checking everything and keeping it clean. By following the steps above, you can keep your trailer brake system in good working order and stay safe on the road.

Remember, if you’re not sure what to do, seek professional advice so you don’t endanger yourself and others with your caravan.

My name is Tom Vanderbilt. I am an automotive expert and renowned for my profound knowledge of automobiles. I have made significant contributions to the industry through my experience and expertise. I have a natural curiosity and fascination for cars. My journey is to explore the intricate dynamics between people, their vehicles, and the ever-evolving transportation landscape.

Leave a Comment