Troubleshooting 2015 GMC 2500 Factory Brake Controller With No Signal at 7-Way Connection

Question

Question:

I have a 2015 GMC 2500 Duramax and it has a factory brake controller. When I hook up to a trailer that has brakes the controller does not even recognize that it is hooked to a trailer therefore trailer brakes will not work automatically or manually. When I have a helper apply manual brake on controller I don’t get a signal to 7 blade receptical with a test light either. If you can help that would be great thanks

asked by: Troy B

0

Expert Reply:

There are a couple connections that need to be made to activate your factory brake controller. You will need to attach a couple wires under the hood to give power to your controller. If these are connected then you will want to check the engine bay fuse block for fuse #1 in the micro J-case fuses which is the trailer brake fuse.

expert reply by: Jason S

0

Answer 1

According to the owner's manual for a 2015 GMC Sierra, the "Service Trailer Brake System" error message can appear on models equipped with the factory integrated trailer brake controller (ITBC) and represents a problem in…

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Answer 2

To determine why you do not have any power on the blue brake output wire, I recommend starting at your brake controller. First, make sure the brake controller is on and receiving power. Most brake controllers have 4 wires, blue (brake output to…

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Answer 3

It is possible that the 12 volt circuit is not present on your 2009 Chevy Silverado or GMC Sierra. For some reason GM did not always complete the tow package wiring. If the proper wires are not already present on your truck then you can manually run…

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Answer 4

There isn't anything like an autonomous controller that would step up if the factory controller fails. I'd simply bypass the existing factory brake controller. The GM ITBC, although it works better now than the earlier models has been…

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Answer 5

The lid of the Bright Way Trailer Breakaway ICU Kit with 12V, 5-Amp-Hour Battery, Charger, and Wire Loom #BW94FR that you referenced has a wiring diagram shown that details how it wires. Not seen is there is a single wire that runs up to running…

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Answer 6

It could be a tow package fuse on the vehicle. Use the owners manual to find the locations of fuses/relays related to the tow package wiring to check them and replace as needed. If the issue is not a fuse or relay then you can test the vehicle side…

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Answer 7

I have added an image below for the Bright Way Push-to-Test ICU Trailer Breakaway Kit #BW94FR as well as an installation video that is also very helpful. Here is where all the wires will connect from both the battery box and the breakaway switch.…

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Answer 8

If your breakaway battery is dead, your brakes should operate while connected to your vehicle's 7-way trailer connector. If your brakes are not operating, then it sounds like you might have a short in the brake wiring of the trailer. Battery…

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Answer 9

If you are referring to two white wires from the brake magnet that are coming from the rear of each electric brake assembly, then it would not matter which wire is connected to ground and which wire is used for the brake feed. The magnet that…

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Answer 10

Trailer wiring generally uses 16 gauge wire, part #16-1-1. However, with a long trailer like yours you may want to go with a larger like 14 gauge #DW07550-1 or even 12 gauge #12-1-1. Each size is sold by the foot. You will need to have the lights at…

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Answer 11

When a trailer with electric brakes is connected to a vehicle that has a brake controller that brake controller is sensing the draw of the brake magnets by sending back a small amount of voltage on the blue wire. The brake controller also get's…

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Answer 12

If you're speaking of the OEM brake controller, then the ITBC on the 2021 GMC Sierra is compatible with electric over hydraulic braking systems such as the Dexter brake actuator used on your Keystone Montana Legacy. If your truck has the OEM…

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Troubleshooting 2015 GMC 2500 Factory Brake Controller With No Signal at 7-Way Connection

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