Trailer brake alert?

ron mexico75 · August 28, 2019

I’ve gotten the message “service trailer brake system“ several times over the past couple of years it usually just goes away after a time or 2. I was towing a 6 x 12 U-Haul trailer this past week. I must’ve gotten that alert 25 to 30 times in a row it would not stop. Then all the sudden it stopped on my three hour trip.

Coming back yesterday three hours did not get the error message once. Started my truck up this morning to go into work without any trailer hooked up and got the message again.

Anybody here experience this or know what might be causing it?

Truck is a 2015 2500 HD Silverado.

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SkiDooNick700 · August 28, 2019

Mine was doing this, where it sounds a few chimes too right? Dealer replaced some module or something, I can't recall. Was about two years or so ago.

ron mexico75 · August 28, 2019

Yes exactly, it chimes every time it comes up on the DIC.

The truck is out of warranty though. I’m sure this is a several hundred dollar fix if I took it in.

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EJCarter · August 31, 2019

My truck does it every time I hook up a trailer if the truck is running. If the truck is not running when I hook up a trailer, it never does it. Give this a try if you haven't and see if it corrects the issue...

ron mexico75 · August 31, 2019

My truck does it every time I hook up a trailer if the truck is running. If the truck is not running when I hook up a trailer, it never does it. Give this a try if you haven't and see if it corrects the issue...

I’ll have to remember that and give it a try next time. Thanks

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SMKN LS1 · September 13, 2019

My 2016 3500 had this same problem. Service Trailer warning kept coming up while both towing and driving without a trailer. The dealer was no help as they blamed it on what they thought was corrosion in the 7 pin connector. The tech didn’t know that the contacts are brass and have a brass color lol. There was no corrosion.

i did some research and narrowed the root cause to two possibilities:

GMC Brake Controller Module 23337305

or

Trailer Brake Controller 84108373

I replaced the module, located above the spare tire, and the warning disappeared. Took fifteen minutes to swap out.

When I told the dealer service writer, they had no idea what a brake controller module was. Oh well. Hope it helps someone here.

ron mexico75 · September 13, 2019

My 2016 3500 had this same problem. Service Trailer warning kept coming up while both towing and driving without a trailer. The dealer was no help as they blamed it on what they thought was corrosion in the 7 pin connector. The tech didn’t know that the contacts are brass and have a brass color lol. There was no corrosion.

i did some research and narrowed the root cause to two possibilities:

GMC Brake Controller Module 23337305
or
Trailer Brake Controller 84108373

I replaced the module, located above the spare tire, and the warning disappeared. Took fifteen minutes to swap out.
When I told the dealer service writer, they had no idea what a brake controller module was. Oh well. Hope it helps someone here.

That’s great info...THANKS!!!

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q.poole · September 17, 2019

On 9/12/2019 at 9:53 PM, SMKN LS1 said:

My 2016 3500 had this same problem. Service Trailer warning kept coming up while both towing and driving without a trailer. The dealer was no help as they blamed it on what they thought was corrosion in the 7 pin connector. The tech didn’t know that the contacts are brass and have a brass color lol. There was no corrosion.

i did some research and narrowed the root cause to two possibilities:

GMC Brake Controller Module 23337305

or

Trailer Brake Controller 84108373

I replaced the module, located above the spare tire, and the warning disappeared. Took fifteen minutes to swap out.

When I told the dealer service writer, they had no idea what a brake controller module was. Oh well. Hope it helps someone here.