Troubleshooting OEM Trailer Brake Controller on 2019 Chevy Suburban

Published 07/22/2021

Question:

2019 suburban trailer breaks not working I have confirmed there’s no power to the trucks plug By squeezing the manual break actuator this would send voltage to the plug . No signal no power at the plug The dash display shows the break gain graph applying the break or squeezing the manual switch doesn’t show any movement or any indication of operating just the gray graph What do you think Can you help me I need my trailer breaks to go home. They just stopped working. Thank you.

asked by: Tim W

Expert Reply:

Since you have the OEM brake controller, the operation of the controller is more complicated and involved than an aftermarket controller would be.

If the controller worked at one point then stopped, I'd suspect a blown fuse to be the cause. The fuse in position # 36 in the fuse panel in the owner's manual activates the ITBC, the factory brake controller. If the fuse is blown, before plugging the trailer back in, you'll want to closely examine the brake output circuit on the trailer, which is typically a blue wire. Trace the wire from the trailer connector back to the brakes looking for broken wires or wires with worn or cracked insulation that would allow the wire to short out on the trailer frame. A damaged or corroded trailer connector on the vehicle or trailer could also cause this.

If the fuse isn't blown, you'll want to have the dealer look at your vehicle.

expert reply by: Mike L