Troubleshooting Pilot Electronic Brake Controller Not Activating Trailer Brakes

Updated 01/08/2025 | Published 01/01/2016

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Digital Multimeter with 42" Long Test Leads - LED Display

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Question:

my break controller when I step on the brake just the red dot comes up not any numbers come up what could be the problem? my brake controller is not working it just shows the red dot that is usually between the two numbers no numbers show up and when I have it hooked up to my trailer it does the same thing and doesnt activate the brakes I tried unplugging it and plugging it back in and I also checked the fuses still not working dont know what to do I need to use my trailer tomorrow

asked by: James

Expert Reply:

When the trailer is connected to your vehicle and the brake pedal or manual lever is not activated, the Pilot Electronic Brake Controller # 80550 should display a ".C" to indicate that the controller is reading the trailer. If your controller only ever shows the dot, the brake controller is not recognizing that the trailer is connected.

The first thing I recommend checking is the trailer connector at the back of the vehicle and on the trailer. You will want to make sure that the connector is clean and free of corrosion both on the outside of the connector and inside where the wires are connected.

If the trailer connector is clean, there may be a poor connection on the blue wire for the brake line. There are a couple of places to check for the brake wire's signal.

To determine if the issue is in the controller or with the wiring, you can cut the blue wire from the brake controller a few inches back from the controller and use a multimeter # PT89ZR to test the brake signal coming from the controller. Depending on the size and number of brakes, the amperage should fall into a specific range. I have attached a photo showing these ranges for you. If the controller does not test within the correct amperage for your set-up, there may be an issue with the brake controller.

If the signal from the brake controller is testing correctly, the next thing is to use a circuit tester # PTW2993 to test the brake wire pin on the vehicle's trailer connector. If the brake signal is not reaching the vehicle trailer connector, the problem is in the vehicle's brake controller wiring. If the signal is reaching the connector, you will then want to check to wiring on the trailer the trailer's brakes.

You can check the wiring to the brakes for any damage that may be preventing the brake controller from recognizing the trailer's brakes. If the wiring is in good shape, you can check the brake magnets to ensure they are working properly. I have attached a help article on testing the brake magnets for you.

I have also attached the Pilot's installation instructions for you.

expert reply by: Victoria B

click to enlarge

Larry L.

5/18/2020

4 wires connected properly. no power to brake controller. 30 amp fuse factory installed. 2016 chevy Colorado with tow package. the trailer does not have to be connected to show power does it?

Chris R.

5/21/2020

The trailer doesn't need to be connected for the controller to be powered. Did you try replacing the 30 amp fuse under the hood to see if it's possibly a bad fuse?

Daveb

1/8/2025

@ChrisR Did Larry figure out the problem? The post is from 2020… I’m having the same problem now, bought a new controller and changed the fuse and still not working.

Jerred H.

1/8/2025

@Daveb Did you follow the rest of the troubleshooting steps from the answer above? That's an extremely thorough answer and would be the steps to follow if you have replaced the fuse already.