Troubleshooting No Trailer Connected Issue with Factory Integrated Brake Controller

Published 10/05/2018

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10 Gauge Wire - Blue Primary - Per Foot

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Dielectric Grease for Electrical Connectors, 2 oz.

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LCD Digital Circuit Tester

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Question:

2008 2500HD Silverado Duramax ITBC For quite a while now I have had an intermittent problem with my truck sensing the trailer connection. Sometime I would have to plug and unplug the trailer into my truck several times before I would get the Trailer Connected message on the dash. The problem has gotten worse and worse and now I cannot get the Trailer Connected message at all and I have no trailer brake operation. I had my friend plug into my trailer with his truck and no problems at all. This tells me the problem is not my trailer but it is my truck. I have replaced the trailer brake relay in the rear of the truck. I replaced the brake switch on the brake pedal. I am wondering if it could be the factory installed ITBC in the dash. Any Thoughts?

asked by: Dan

Expert Reply:

Normally when you are having a trailer connection issue, it is because there is corrosion or debris in the connection. The 7-way trailer connector on your truck at the 5 o'clock pin position is the brake controller output. This pin is where the brake controller will see a slight draw when the trailer is connected. Over time, build up on the pins will cause the vehicle not to sense the trailer so you may simply need to clean that connection with some sand paper or steel wool and then use some dielectric grease like # 11755 to keep the connection from that issue in the future.

The other possibility is that there is no power getting to that pin due to a short in the wire. You can test this with a circuit tester like # PTW2992. With the circuit tester grounded to your frame and the probe on the 5 o'clock pin, you should see a trailer connected message and be able to hit the manual override on the controller to see the voltage increase and the light in the tester get brighter. If you do not see this after cleaning the trailer pins, then you will want to trace that brake output wire probing every few feet to test for function to determine the short. To determine if it is a factory brake controller issue you will want to test the brake output wire under your dash close to the brake controller connection. If you have signal there, you may want to simply run a new wire # 10-1-1 from that point back to the pin location.

If you don't have power from the factory brake controller, you will either want to take it in to the dealer for repair or replacement or I recommend replacing it with # 90195 which is far superior to that factory integrated brake controller.

expert reply by: Jason S