Troubleshooting a Factory Brake Controller in a 2008 Chevy Silverado

Question:

On my 2008 Silverado, I get an error message telling me to service trailer brakes even when I dont have my trailer hooked up.And the brakes dont work when it is hooked up?

asked by: Charlie

Expert Reply:

Sounds like the factory integrated brake controller on your 2008 Chevy Silverado is having some type of issue. Either there is a problem with the wiring of it or the controller itself is bad.

Testing the brake controller is fairly easy. Sever the blue brake output wire and then apply the manual slide. Using a circuit tester like part # PTW2993, you should get output to the controller side of the wire you severed. If the manual slide activates the trailer brake output wire properly, try the brake pedal. If the brake pedal activates the brake output properly also then the problem is farther back either in the vehicle wiring or on the trailer.

If either the brake pedal or the manual slide are not functioning properly you will need to test the wires going into the brake controller. Make sure you have power entering the brake controller on the black wire. On the red wire you will only want power when the brake pedal is pressed.

If there is power on the red wire before the brake pedal is pressed you have connected the red wire from the brake controller to the wrong circuit. You would then need to find the brake switch wire that has power ONLY when the brake pedal is activated.

If these connections check out and the brake controller is properly grounded then there is possibly a problem inside the brake controller.

I am including a link to a video that will show you how to test the wiring on a brake controller.

If you are unable to test these wires your best option would be to take your truck to your local Chevy dealer and have them diagnose the problem.