Trailer Brake Module Fault – How to Quickly Fix It?

The Trailer Brake Module Fault is a common problem experienced by pickup truck owners. You can find most of these being discussed in Ford forums online. This typically occurs when towing a trailer, but there have been complaints that it also happens when the vehicle is not pulling anything.

In this article, we will show you some quick solutions for this problem. We will discuss here some other ways to diagnose the issue as well if the easy fixes fail to work.

Before you read this, you should know that Ford has a service bulletin number 21B08-S1 and it says to reprogram the electronic modules. It corrects some software problems affecting heated mirrors and trailer relay module. If you have this problem in your F150 (2021 and younger), give it a go!

How the Trailer Brake Module Works

The Trailer Brake Module is a device that helps control the brakes on a trailer. It is usually located at the rear of the vehicle, and it works by sending a signal to the trailer's braking system when the vehicle's brakes are applied.

The Trailer Brake Module is an important part of a vehicle's braking system, and it can be beneficial in many ways. For one, it prevents the trailer from jackknifing during sudden stops. Additionally, it can help keep the trailer's brakes from locking up and causing skidding. Finally, it provides extra stopping power when needed, such as during emergency stops.

However, if the Trailer Brake Module fails, it can cause serious problems. For example, if the module is not working properly, the trailer's brakes may not engage when the vehicle's brakes are applied. This can lead to the trailer skidding.

On the other hand, having an error pointing to the Trailer Brake Control module even if you are not towing anything may potentially trigger some of the safety equipment of your vehicle and limit its performance. But then again, many people who have encountered the same problem claimed that it does not really result in any noticeable change in the way they drive so they tend to just ignore it.

No matter what, it is important to make sure that the trailer brake module is working properly before hitting the road.

Problems Possibly Affecting the Trailer Brake Module

It's important to find the actual problem that can trigger this error message in your truck. Very often, the reason is not that obvious. We couldn't list all the possible problems in this article, but we tried to include the most common ones on our list.

These may include the following:

1. Trailer Brake Module Failure

Addressing the elephant in the room, when you see the "Trailer Brake Module Fault" error message on your vehicle's dash, it likely means that there is a problem with the trailer brake module.

To diagnose the problem, start by visually inspecting the trailer brake module for any damage. If you see any form of physical damage or burns on its casing or internal components, that's a good sign that you need to replace it. In addition, you can utilize a multimeter to test whether or not its electrical parts are still functioning.

2. Wiring Issues

One of the common culprits of the "Trailer Brake Module Fault" error is a problem with the wiring. To diagnose this, start by visually inspecting the wiring harness for any dirt or corrosion.

Next, check the wires for any traces of fraying, breaks, or burns. In the absence of these signs, you can use a multimeter to test the continuity of the wiring. This will help you determine if there is a break in the wire somewhere.

Finally, make sure that all connections are secure. Loose connections can cause this error, too. Tighten or replace the connectors as necessary.

Any problems with wiring will most likely be solved by buying a new wiring harness and installing it.

3. ECU Malfunction

The engine control unit (ECU) is a computer that serves as the brain of your vehicle. If this crucial part malfunctions, the different electronic components of your auto will often follow.

If the problem is traced all the way to the vehicle's ECU, you will need to have it repaired via reflashing or upgrading its software to patch up any stored errors that may be interfering with the Trailer Brake Module. However, if the ECU hardware has already been compromised due to physical damage caused by strong vibrations within the vehicle, major impacts, or electrical shorting, you may be in for a costly replacement of this part.

4. Sensor Problem

A problem with the trailer brake sensor may also activate the "Trailer Brake Module Fault" warning on your dashboard. To identify the problem, begin by visually inspecting the sensor for any dirt or damage that could be hindering its proper function. Then, use a multimeter to test the sensor if it is getting enough power or is still working as it should. If the sensor is not functioning well, it will need to be replaced.

In some vehicles, these sensors are faulty and need to be replaced with updated ones. The F-150 is one such truck, you may just get the new sensor. Fortunately, it will not cost you a fortune to get one.

5. Drained Battery

A "Trailer Brake Module Fault" can be caused by several factors in the charging system of the vehicle. The most common is a drained battery.

If the battery is indeed the culprit, you can connect it to an external charger to juice it up. If your auto is still capable of starting the engine, you can also charge the battery while the engine is running. If the battery is too far gone, however, it may need to be replaced entirely.

6. Worn Brake Pads

Lastly, evaluate the brake pads of your trailer if they are already worn. If they are no longer capable of stopping the wheels properly, they should be replaced immediately.

Quick Fixes to Trailer Brake Module Fault

There's a possibility that the Trailer Brake Module fault you are experiencing in your vehicle may not necessarily point out a defect on the module itself. Most of the time, these are due to software glitches in the system of your auto.

So, if you find yourself in this situation, there are some quick fixes that you can apply if you are getting a Trailer Brake Module Fault in your auto. Here are some ways to go around the problem:

1. Restart the Engine

Sometimes, this can be as simple as a minor glitch in the system of your vehicle. Chances are it might be gone the next time you restart your auto or after driving it around a hundred miles.

2. Reset the Battery

You can also refresh the settings of your ride by disconnecting the cables from your battery. Be sure to detach the negative cable first to prevent electricity from arcing in your engine bay. Leave your vehicle in that state for no about 10 minutes, and then reconnect the cables back to your battery.

If the problem does not go away after restarting your truck, you will need a more thorough inspection to identify the actual problem.

3. Recalibrate the Device

Most trailer brake controllers nowadays are self-calibrating. With that, all you have to do is plug its harness into your vehicle and wait for it to flash a signal or light that the calibration has been completed.

Some may ask you to enter your personal settings with its interface during the process. Others may even require to you to set the maximum amount of power that should be applied to your brakes. You may also need to set the sensitivity level, which determines how forcefully it will apply the brakes at certain conditions.

Normally, these are coupled with step-by-step prompts, so it should not be that hard for you to follow.

4. Take your car in for the inspection

If you can't locate and solve the problem on your own, you better take your vehicle to a professional mechanic. It won't cost you a fortune to see if there is a certain code in the ECU that triggers this problem or maybe you have a glitch in the software of your car.

You may go to the dealership or choose an independent repair shop to have your car inspected. Usually, the reason for the Trailer Brake Module fault is found within minutes by a professional mechanic.

Conclusion

A "Trailer Brake Module Fault" warning in your dashboard can mean a lot of things. If you're lucky, you may be able to do away with the simple fixes shown here. However, if it is traced to a faulty component, then, that problematic part will have to be repaired or replaced to get rid of the error message.