Troubleshooting Factory Brake Controller In My 24' GMC Not Working With My Brakes

Updated 08/05/2025 | Published 08/01/2025

Question:

Hello. I have 2021 Keystone Montana Legacy with electric over hydraulic brakes that won’t work with my 2024 GMC Sierra 2500 with the factory brake control. Will one of your adapters fix this problem or will I need to install an aftermarket brake control? Thanks

asked by: Steve R

Expert Reply:

Hey Steve,

This is a common issue with GMC that their factory brake controllers should work but end up not working with the electric over hydraulic brake systems. Your best bet is going with an aftermarket controller that will. For your vehicle I recommend the Tekonsha # TK52HR. This is a plug and play installation and works great with electric over hydraulic systems. The Prodigy P3 is one of the top after market controllers out there.

There is sometimes a setting internally on those GMC vehicles that needs to be activated by a dealership for it to work. However, I have seen it work and also not work so it is hard to tell with certainty that it will do the job. I recommend upgrading to an aftermarket controller. Has it always not worked or is this a new issue?

expert reply by: Nick S

Steve R.

8/5/2025

It just started with this trailer which I just purchased. Works fine with standard electric brakes

Nick S.

8/5/2025

@SteveR It seems to only being electric over hydraulic systems with most factory brake controllers. I will say they tend to be not the greatest in quality. An upgraded aftermarket should fix any issue going forward.