Troubleshooting The Curt Triflex Brake Controller On A 2017 GMC Yukon

Question:

Curt C24VV Triflex Brake Controller: The brake controller on my 2017 GMC Yukon stopped working i.e. no indicators are illuminated at all and trailer is not braking. My diagnosis indicates that I am no longer getting 12v on the pin black wire where the harness connects to the truck ITBC plug? I do get 12v on the stop light wire blue pin when I activate the brake pedal. Are you able to tell me what fuse feeds that pin? Ive checked all the fuses that I can find that seem to be related to the trailer wiring but so far cant find one that is blown. Thanks

asked by: Fred H

Expert Reply:

You will first need to determine why The Curt Triflex Controller # C24VV is not working. You will need to check the correct fuse that corresponds to the brake control and its power supply.

In the under hood fuse block (located near battery) fuse 36 is what you need to check.

After checking if the trailer brake fuse is intact, you should then acquire a hook probe circuit tester # PTW2993. When the vehicle is on you will want to test the power wire (black) running into the controller. If it lights up then the problem will be with the wiring harness and you'll have to trace the power wire back as far as you can to check for shorts or breaks in the line. If that light doesn't illuminate then your brake controller is faulty and will have to buy a new Curt Triflex Controller # C24VV.

expert reply by: Noah E