Trailer Brake Controller

squireofgothos88 · August 18, 2019

Can this be installed on a 2019 Silverado? I need to help someone tow a horse trailer but haven’t set up my truck for towing yet. The truck came with a wiring harness for trailer brake controllers. I like the OEM look.

"I know I can do it," Todd Downey said, helping himself to another ear of corn from the steaming bowl.

eppieguy · August 18, 2019

No, it cannot.

JR09country · August 18, 2019

From other members and from what i heave read you cannot add oem trailer brake after the fact. You will be able to add an aftermarket one though.

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squireofgothos88 · August 18, 2019

Well that answers that.

"I know I can do it," Todd Downey said, helping himself to another ear of corn from the steaming bowl.

UncleDave · August 18, 2019

Is there a good aftermarket TBC that will fit in the stock location? That would be much cleaner than having some box hanging down under the dash.

ChinkySuperman · August 19, 2019

15 hours ago, UncleDave said:

That would be much cleaner than having some box hanging down under the dash.

I wholeheartedly agree with this, this is what I had on my last truck and it looked super tacky.

KEEPER OF SECRETS · August 19, 2019

21 hours ago, UncleDave said:

Is there a good aftermarket TBC that will fit in the stock location? That would be much cleaner than having some box hanging down under the dash.

As of today, no sir, nothing exists to bolt into the factory spot covered with the push in blank piece of plastic.

Box with wires is all we get. The top smaller glove box mounting location might be an option, or the rarely used top dash cubby hole.

A lot of us are in the same boat with no TBC from factory.

-Patrick-

Bradg · December 25, 2019

The blank push in cover has a harness behind it where the stock trailer brake controller goes. Can’t you just buy a stock controller and plug into that? Why would there be the harness there if it doesn’t work?

AlaskaErik · December 25, 2019

22 minutes ago, Bradg said:

The blank push in cover has a harness behind it where the stock trailer brake controller goes. Can’t you just buy a stock controller and plug into that? Why would there be the harness there if it doesn’t work?

Because what you think is a stock controller is in reality nothing more than a mechanical switch. The brains are elsewhere in the truck and if your truck didn't come with a factory controller you don't have the brains. An aftermarket controller is the mechanical switch and the brains all in one package.

Bradg · December 25, 2019

29 minutes ago, AlaskaErik said:

Because what you think is a stock controller is in reality nothing more than a mechanical switch. The brains are elsewhere in the truck and if your truck didn't come with a factory controller you don't have the brains. An aftermarket controller is the mechanical switch and the brains all in one package.

Yea I get that. Just wondering why they would run a wire and harness to that blank box if it cannot be used? Doesn’t that wire go to something?

Edited December 25, 2019 by Bradg
Added pic

davester · December 25, 2019

It's there because, most likely, it's cheaper to just have one part with that connector, than to have two parts, (one with, one without), make sure the right one is installed, and to stock two parts for 5+ years.

2016 Sierra Owner · December 26, 2019

13 hours ago, davester said:

It's there because, most likely, it's cheaper to just have one part with that connector, than to have two parts, (one with, one without), make sure the right one is installed, and to stock two parts for 5+ years.

BINGO! And it's not just the trailer wire harness that way. If your truck does not come with it. They just don't use the plug and put a blank over the hole.

TJay74 · December 26, 2019

18 hours ago, Bradg said:

Yea I get that. Just wondering why they would run a wire and harness to that blank box if it cannot be used? Doesn’t that wire go to something?

Because several years ago GM decided it was cheaper to only make the minimal amount needed of parts, one area this happened in is the wiring harness. For the most part now they use 1 harness for each cab configuration for the trucks. That harness has plugs for features that vehicle doesnt have, IE the factory trailer brake controlled.

To answer your question, can you plug a TBC you buy into that plug, yes. Yes you can.

The caveat is it wont work, as said there are multiple things needed. Wiring harnesses, hardware and software. The problem you are going to run into is the software side, the programming for the TBC is not loaded into the trucks modules. It cant be added after the fact either GM addressed this on the K2xx (2014+) when the same question was brought up.

If you want the OEM TBC then buy or order a truck with it from the get go, you cant add it after the fact no matter how hard you try. I dont care what any dealership tells you, what the bosses boss tells you or what your favorite service tech or service manager tells you. The OEM TBC can not be added to the truck after the fact, GM wont allow it and has came out and said so several times now.

BlancoSilverado · December 26, 2019

On 8/18/2019 at 11:58 AM, JR09country said:

From other members and from what i heave read you cannot add oem trailer brake after the fact. You will be able to add an aftermarket one though.

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This is true. Tried it myself.

bamorris2 · December 26, 2019

I’m new to the GM scene with my new Sierra. But coming from an F150, there’s a software program called ForScan that lets you turn these types of features on or off or reprogram almost any of the modules, with just an OBD reader and the free software. Does nothing like that exist for GM vehicles?