2024 Brake controller Problems

Curt Lowe · May 10, 2023

JUST brought a 2024 Silverado 3500 dually, I have a HD trailer GVW of 26K. Electric over Hydraulic brakes. The truck dose not recognize the trailer for brakes. I have 3 other trucks that it works fine with. 15 Silverado 3500, 21 gmc Denali 2500 HD , then hooked up to a 22 DODGE RAM 3500. ALL TRUCKS the trailer worked fine. GM says there is no Problem. go figure. Well their fix is to install a Aftermarket adapter non GM approved on my trailer to get them to work. As everyone knows trailer wiring will not last and needs attended to

the8rotor · May 13, 2023

On 5/9/2023 at 9:18 PM, Curt Lowe said:

JUST brought a 2024 Silverado 3500 dually, I have a HD trailer GVW of 26K. Electric over Hydraulic brakes. The truck dose not recognize the trailer for brakes. I have 3 other trucks that it works fine with. 15 Silverado 3500, 21 gmc Denali 2500 HD , then hooked up to a 22 DODGE RAM 3500. ALL TRUCKS the trailer worked fine. GM says there is no Problem. go figure. Well their fix is to install a Aftermarket adapter non GM approved on my trailer to get them to work. As everyone knows trailer wiring will not last and needs attended to

Are you getting an error on your console when connecting the trailer?

Brain Candle · May 13, 2023

I have a similar problem. I just picked up a 24' 3500 LT SRW diesel. I hooked up to our new toy hauler and started the light test. It ran the test twice, but when I got back to the truck it said that the brakes and trailer were disconnected and to check the trailer wiring. I tested the trailer wiring and hooked a different truck up to the trailer with no issues. I tried the truck on a different trailer and it gave me a similar fault. I tested all the fuses in the truck, found a 30A for the "trailer battery" blown, replaced and re-tested to no avail. I am going to guess that there may be an issue with a module somewhere. My first internet search went to a past service bulletin related to a similar issue in 2020-2021.

Edited May 13, 2023 by Brain Candle

Lionel York · July 6, 2023

Have a new 2024 GMC 2500 Denali Ultimate Diesel, and the trailer braking system does not work when hooked up to my 5th wheel camper.

Edited July 6, 2023 by Lionel York

Lionel York · July 6, 2023

Have a new 2024 GMC 2500 Denali Ultimate and the trailer braking system does not work when hooked up to my 5th wheel camper.

Rototerrier · July 7, 2023

Same issue with 24 3500 DRW Denali. Hooked to fifth wheel at 500 miles and it started randomly throwing the check trailer wiring error and disabling the trailer brakes. Brakes usually stay off for about a minute before coming back. We’ve checked everything on the trailer including replacing the 7 pin with 2 different styles of new plugs. Nothing fixed it and it’s seemingly random. 800 mile trip and it cut out on me twice on the way and 4 times on the way back. Has 1500 miles on it now. All lights and everything else functioning fine. Just having issues with the brake controller.

Pulled wheels and hubs and checked wiring and brake magnets. All good. Good continuity on all wires.

2022 F350 had zero issues with this same rv. Rv is a 2023 337RLS.

Truck is currently in the shop. Haven’t heard anything yet. Not feeling optimistic.

Edited July 7, 2023 by Rototerrier

64BAwagon · July 7, 2023

On 5/13/2023 at 1:53 PM, Brain Candle said:

I have a similar problem. I just picked up a 24' 3500 LT SRW diesel. I hooked up to our new toy hauler and started the light test. It ran the test twice, but when I got back to the truck it said that the brakes and trailer were disconnected and to check the trailer wiring. I tested the trailer wiring and hooked a different truck up to the trailer with no issues. I tried the truck on a different trailer and it gave me a similar fault. I tested all the fuses in the truck, found a 30A for the "trailer battery" blown, replaced and re-tested to no avail. I am going to guess that there may be an issue with a module somewhere. My first internet search went to a past service bulletin related to a similar issue in 2020-2021.

The modules on the 2024 trucks are different than the ones used on the 2020 and 2021 models.

I have said it before but I think the issue a lot of times is that the new trucks have a very sophisticated electronic setup in order to provide all of the data but we are hooking them up to trailers that use wiring processes from the 50's For instance, look at the junction box on any trailer where the umbilical (7 way) cord connects, its a nightmare.

I have seen multiple posts on a Grand design tech site that I contribute to. The majority of them are resolved on the trailer. As sloppy as the RV industry is it only takes one bad connector to cause a fault. The last one I saw was from a chafed (unshielded) wire on the brakes that was inside the axle tube.

Scott

Kyleb100 · July 8, 2023

I have the same issue with my 2024 sierra 3500. I get the “check trailer wiring” “service trailer brake system” intermittently. I spent $700 bucks to have the entire trailer re-wired from the pigtail to the axles which didn’t correct the issue. My dealer is Dave Smith in Idaho and they have been good to work with so far on the issue. They couldn’t identify anything with their trailer simulator or pull any codes but they were able to find a service bulletin #23-NA-113 that may identify the issue specifically on 2024 2500s/3500s. The service bulletin states the trailer solar panels may charge the trailer batteries to a level higher than the truck battery and cause it to backfeed to the truck which places the trailer brake module into a “safe mode”. It also says that GM is working on a solution but I’m not holding my breath.

I haven’t had much of an opportunity to test it myself; but you can try turning your battery disconnect switch to “off”, shutting off your solar controller, or disconnecting your solar panels to see if it resolves the issue.

This issue is driving me crazy after a recent 600 mile trip with intermittent trailer brakes so I’m hoping for a quick fix and not the bandaid solution provided in the service bulletin.

edit: added 2500s to the list of affected trucks

Edited July 8, 2023 by Kyleb100

UWSkier · July 8, 2023

I noticed my trailer brakes disconnected randomly once today too. I'm about to head out on a 4000 mile RV trip. I'll be mighty upset if I don't have trailer brakes 100% of the time...

RANT: These stupid electronics on these new trucks are just dumb. I get the "smart trailer" nonsense, but if you're going to do that, why make it so fragile? And why make it wreck other stuff, like my existing camera system? I had none of these issues with my last truck... Didn't need to drop money on a stupid adapter for cameras, etc.

Kyleb100 · July 8, 2023

10 minutes ago, UWSkier said:

I noticed my trailer brakes disconnected randomly once today too. I'm about to head out on a 4000 mile RV trip. I'll be mighty upset if I don't have trailer brakes 100% of the time...

RANT: These stupid electronics on these new trucks are just dumb. I get the "smart trailer" nonsense, but if you're going to do that, why make it so fragile? And why make it wreck other stuff, like my existing camera system? I had none of these issues with my last truck... Didn't need to drop money on a stupid adapter for cameras, etc.

Curt makes a bluetooth trailer brake controller that works pretty well. See if your dealer will loan you one from their parts department for your trip since you are working through the issue with them while under warranty. They are around $300 to buy, but they plug directly into your 7 way receptacle and don’t need any additional wiring to bypass the trucks controller. It will at least get you on the road for your trip.

Rototerrier · July 8, 2023

6 hours ago, Kyleb100 said:

I have the same issue with my 2024 sierra 3500. I get the “check trailer wiring” “service trailer brake system” intermittently. I spent $700 bucks to have the entire trailer re-wired from the pigtail to the axles which didn’t correct the issue. My dealer is Dave Smith in Idaho and they have been good to work with so far on the issue. They couldn’t identify anything with their trailer simulator or pull any codes but they were able to find a service bulletin #23-NA-113 that may identify the issue specifically on 2024 3500s. The service bulletin states the trailer solar panels may charge the trailer batteries to a level higher than the truck battery and cause it to backfeed to the truck which places the trailer brake module into a “safe mode”. It also says that GM is working on a solution but I’m not holding my breath.

I haven’t had much of an opportunity to test it myself; but you can try turning your battery disconnect switch to “off”, shutting off your solar controller, or disconnecting your solar panels to see if it resolves the issue.

This issue is driving me crazy after a recent 600 mile trip with intermittent trailer brakes so I’m hoping for a quick fix and not the bandaid solution provided in the service bulletin.

Thank you for sharing this. I do have Solar on my rig. Would you happen to have a link to or a photo of that bulletin?

Kyleb100 · July 8, 2023

32 minutes ago, Rototerrier said:

Thank you for sharing this. I do have Solar on my rig. Would you happen to have a link to or a photo of that bulletin?

I have a copy of it at home that the dealer provided to me. I’ll post it later when I get home and have some time

Rototerrier · July 8, 2023

1 hour ago, Kyleb100 said:

I have a copy of it at home that the dealer provided to me. I’ll post it later when I get home and have some time

Thank you. If i hear anything meaningful from my dealer I’ll be sure to share.

Kyleb100 · July 8, 2023

4 hours ago, Rototerrier said:

Thank you for sharing this. I do have Solar on my rig. Would you happen to have a link to or a photo of that bulletin?

Rototerrier · July 8, 2023

Well, isn’t that nice. This is my exact issue. I’ve forwarded this to my service advisor and will be picking my truck up this morning. I’ll get my solar disabled on the rv and do some testing today.

Thank you again for sharing. I suspect this is going to help a lot of people out as more of these trucks start hitting the road. Most rvs that will be towed by this size truck will have solar.