Chevy and GMC Duramax Diesel Forum banner
  • Hey Everyone! Enter your ride HERE to be a part of this months Ride of the Month Challenge!
1 - 2 of 2 Posts

Premium Member
2,284 Posts
Discussion Starter · #1 ·
Looking for some help on my 16 drw. Trailer brakes have stopped working.
No voltage at the plug when manually applied or by brake
fuses are both good.
No service brake messages .
does not ever say trailer is connected
both trailers ive tried work fine on my other truck
12v and ground both showing up at the trailer brake module above spare tire
Have continuity from blue wire at TBM over to the plug in the bumper

I know it was working before and I haven’t changed anything on the vehicle. So my best guess is the TBM has either crapped out which is odd no codes or anything, or maybe the controller on the dash where you set gain is gone out. I really dont want to just buy parts and hope for the best. Wasnt sure if something like a solus or tech 2 can go in and access the TBM to do any check/tests etc.

4,143 Posts
If the ABS light is on in your dash all the time, that will stop the TBCM from working. Many people have replaced the trailer brake relay, not the module, and that fixed their problem New relays are plug and play, new modules need programming. Concentrate on the TRAILER CONNECTED message problem and solve that. Then your brakes will probably work

Get the wiring diagram in the ELECTRICAL MANUAL for your truck year and model here Body Builder Manuals - GM Upfitter Click your year model and the different publications should be displayed.
  • Like
Reactions: JimmyD
1 - 2 of 2 Posts