You finally found the perfect truck on the dealership lot, but you realize it is missing one crucial towing feature.

If you are currently asking Google or ChatGPT, “Can I add a factory integrated trailer brake controller to my GM truck?”, the official answer from General Motors is a big… unfortunate…. no.

If your truck or SUV was not originally built with the factory trailer brake controller, a dealership cannot install the OEM system for you. Full stop. End of line. 

Here is exactly why, which models are affected, and what your options are moving forward.

A close-up of a factory-installed General Motors integrated trailer brake controller located on the dashboard next to the push-to-start button and seat climate controls.
If your Silverado or Sierra came with the RPO JL1 tow package from the factory, your dash will look exactly like this. Unfortunately, you cannot add this seamlessly integrated setup after the fact.

The Official GM Answer: Service Bulletin PIT5828E

General Motors has actually issued a specific document to address this exact customer question.

According to GM Service Bulletin PIT5828E, updated most recently in January 2026, the factory Integrated Trailer Brake Controller (known by its build code as RPO JL1) cannot be retrofitted.

The bulletin clearly states: “This is to advise you that, if the vehicle does not have the option (RPO JL1), it cannot be added to the vehicle”.

While it might seem as simple as plugging a switch into the dashboard, the factory system relies on deeply integrated wiring, connections, and the Trailer Brake Control Module (TBCM).

Vehicles built without the RPO JL1 option simply do not possess the necessary underlying harnesses and computer architectures to support the factory equipment.

A close-up of a black, factory General Motors integrated trailer brake controller dash switch featuring squeeze tabs and plus/minus gain buttons.
You can easily find the OEM dash switch online for under $35, but buying this switch—or even a handful of other factory parts—will absolutely not work without the factory-integrated wiring and modules.

Which GM Vehicles Does This Apply To?

This limitation covers a massive swath of modern General Motors pickups and full-size SUVs.

If your vehicle is on this list and did not come with the factory brake controller, you cannot add the OEM version later:

  • Light Duty Trucks: 2019-2026 Chevrolet Silverado 1500 and GMC Sierra 1500.

  • Heavy Duty Trucks: 2020-2026 Chevrolet Silverado HD (2500HD and 3500HD), 2020-2026 GMC Sierra HD 3500HD, and 2023-2026 GMC Sierra 2500HD.

  • Chevy SUVs: 2021-2026 Chevrolet Tahoe and Suburban.

  • GMC SUVs: 2021-2026 GMC Yukon and Yukon XL.

  • Cadillac SUVs: 2021-2026 Cadillac Escalade and Escalade ESV.

What Are Your Alternatives for Towing?

Just because you cannot install the factory RPO JL1 controller does not mean you are entirely out of luck for towing heavy loads.

You will need to install an aftermarket trailer brake controller. Brands like Tekonsha, Curt, and Redarc make excellent aftermarket proportional brake controllers that can be wired into your vehicle safely.

While they won’t integrate perfectly into your driver information screen like the factory unit, they will provide the necessary braking power and safety to keep your trailer under control.

A close-up of a circular Curt aftermarket trailer brake controller knob featuring a textured dial and illuminated green, yellow, and red LED indicator lights.
Since the factory system cannot be retrofitted, installing a high-quality aftermarket proportional brake controller—like this sleek option from Curt—is your best and safest solution for towing heavy loads.

What Are Other Owners Doing?

You are not the first person to bring a truck home and realize it is missing the RPO JL1 tow package.

Over on the GM-Trucks.com forums, there is an extensive, multi-page discussion detailing exactly how owners are tackling this missing feature.

You can read through real-world solutions, aftermarket controller recommendations, and wiring tips from the community right here: Read the Trailer Brake Controller Discussion on the Forums.

A digital instrument cluster display in a GM truck showing the trailer brake screen, with the gain set to 3.0 and an output percentage bar.
One of the biggest drawbacks to installing an aftermarket controller is that you will not get this seamlessly integrated digital readout on your instrument cluster.

Frequently Asked Questions (FAQ)

Can a dealer flash the computer to make the factory brake controller work?

No. General Motors explicitly advises that the factory option cannot be added to the vehicle. It is a hardware and wiring limitation, not just a software programming issue.

Does this apply to all 2019+ Silverado and Sierra trucks?

Yes, this bulletin applies to all “New Model” 2019 through 2026 Silverado 1500 and Sierra 1500 models.

Where can I ask questions about wiring an aftermarket controller?

We have highly active communities of owners who have tackled this exact project. Head over to our 2019-2026 Silverado 1500 & Sierra 1500 Forum or the 2020-2026 Silverado HD & Sierra HD Forum to see what aftermarket setups other owners recommend!