Brake controller issues on 2024 GM HD trucks

[Blaise]

Jlawles2 I think you hit it right on the nose! I disconnected the lead from the MPPT controller to the battery (before reading your post) and still saw the problem. But I now think that the problem persisted because the trailer battery still had a charge level higher than the truck battery. Later I noticed that I did not see the problem during a 1 hour tow. At the time, I just wrote it off to the issue being intermittent. But now I think that after the trailer battery level dropped low enough (below the truck battery), the problem stopped.

familytruckster4 I think there is a newer bulletin - TSB # 23-NA-149, I believe it's from Sept 15, 2023. I think that bulletin (I haven't seen it) suggests replacing the brake controller module with a new one that has been updated to address this issue. I'm trying to get a copy of this bulletin. Will post it here if I can.

I had brought the truck to the dealer, but they didn't find anything. After going home and Googling a bit, I gave the new TSB # to the service coordinator. He said he printed it out and will give it to the tech. Will post any results

[Blaise]

The 3 pages of that TSB are attached

[timh0042]

Mike Sokol has been doing some work in this area. He just sent a note on his RVelectricity substack: https://rvelectricity.substack.com/p...date-prototype

He's looking for testers to see if his hardware solution will fix the issue.

[Boomer]

I had the brake controller replaced and programed on our '24 2500HD. We are currently pulling, so far no issues ! Keeping fingers crossed.

[familytruckster4]

I would tread lightly on using a non GM fix on the truck (I admittedly dont know what that would be) . If its under warranty and you want to preserve that it would be best to let the dealer do the repair on the truck. You may be setting yourself up for denial if other issues come up later.