Bypassing Factory Brake Controller of 2011 GMC Sierra

Updated 05/10/2018 | Published 05/09/2018

Question:

Hello, I have a 2011 GMC sierra 2500 HD with an ITBC I hook on to my trailer and everything works BUT the brakes. I hooked onto a few different trailers that I know everything works and my truck still does not pick up the signal that there is a trailer connected. I tested the brake pin on the truck side and it does not light up, the test light just blinks once and thats it nothing else. I put a brand new trailer plug and cord on the trailer side going into the junction box everything is exactly where it should be all my connections look good etc. I tried a new plug on the truck side and still nothing. The trailer connected message does not display and I do not get any trailer gain when hooked on to any trailer. Any ideas on what it could be and or how to test the rest of the truck? Relay? ITBC module? etc.

asked by: Jake

Expert Reply:

It sounds to me like your integrated brake controller is not able to sense a trailer connection due to an internal problem and needs to be replaced.

I attached a help article that covers the entire process of installing an aftermarket brake controller in a GM truck like yours with an integrated brake controller.

Basically you will wire the P3 part # 90195 to the wire bundle that is under the dash near the brake pedal. I also attached a picture that shows where this is.

There are some connections that will need to be made at the rear of the vehicle and under the hood as well.

expert reply by: Jameson C