Service Trailer Brake System

[bassNspear]

I have a 07 GMC Duramax

Yesterday when i started my truck, "Service Trailer Brake System" popped up on my dash. I checked all the fuses, and none where blowen.

Anyone have any idea what it might be. Called the GMC dealer here in town, and they just said to bring it in.

[Scott K]

Do you have a programmer, or over sized tires on it?

If not, there is a TBCM soft ware update that can be done to it, that may help.

[bassNspear]

i have efi live and 18's on it????

[Scott K]

i have efi live and 18's on it????

I would try a couple things before bringing it to the dealer. First I would see what tire size is programmed into the computer, if it is 35" or larger, adjust it to just below 35". If that doesnt work, remove the program, and return it back to the factory oem setting, and try it for awhile. If it is good, then you will know the issue is with the new software in the programmer, and it doesnt comunicate the correct information back to the TBCM. If that doesnt work, leave the program out of it, and bring it in to the dealer, and let them diagnose it, and update it.

[bassNspear]

maybe i missed the fuse.... do you know what one it would be

[Scott K]

It looks like it is fuse 42 under the hood. I would check that, pull it out, see if there is any corrosion on it. I would also check all of the fuses in both fuse boxes.

[bassNspear]

iv checked every fuse in the truck, and nothing. People are telling me its either the module or the relay from the brake control box??

[Jeremy airjer W]

I would start with the cheapest part first.

[Whoaru99]

I'd take the advice to restore the truck to OEM and start from that approach.

[bassNspear]

but if it was the system, it would have done it right away. My buddy had the same issue, and it was a fuse for him, and he has a program in it. so there has to be something else going on