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Discussion Starter #1
anyone know how to bypass the factory controller. The Shop i9nstalled an Echelon controller because the 3500 dually I drive was throwing a service trailer brakes message, and now they don't know how to make it work.
 

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Don't bypass the factory one, fix the trailer so that it will work correctly. Its either something like a bad ground on the trailer or possibly water in the connector plug.

Service trailer brakes is pretty self explanatory...

Sent from my Droid using the AutoGuide app while not driving...
 

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^X2, if the factory controller is giving a message fix the problem. First off the factory controller is far superior to most aftermarket units in that it is driven by actually brake input. Secondly, replacing it does not fix the problem, even if the aftermarket unit “appears” to work does not mean you have good braking on the trailer.
 

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that was kinda my thought to both responses, but it isn't my truck. The bossman swears the factory system i9sn't going to work for the weight we are going to haul. gvw 40,000. GMC says that if we haul that weight, it will throw that message all the time. That doesn't seem quite right..
 

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so is it throwing the message when you are on the brakes? Or from the get go? If from the start, what does that have to do with weight and even more reason to check and make sure the trailer brakes are working correctly.
 

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Discussion Starter #6
I just started with this truck two days ago, and it threw up a "check trailer wiring" when I hit the brakes, then a service brakes thing. We have 10 trailers sitting here, I Hooked to 5 of them, and got all the same thing. I am told that it was doing that before the new unit was put in.. the local GMC dealer couldn't find any problems. That doesn't surprise me, tho. This was from the git go,, and empty.
 

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First how many axles?, it should be good for 3. Second, the ITBC (integrated trailer brake controler) loves to throw messages for two reasons. 1) You have a bad magnet (it should throw a message), 2) you have a bad ground circuit (again it should throw a message). So rule out that you do not have any of this situations and work from there.
 

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Discussion Starter #8
2 axles, and they are all fairly new trailers.. The bossman will end up cutting the harness, since the local Chevy guy here told him to do that. NOT in writing, of course, so there goes the warranty. I guess maybe I will just pick one of the other available duallys. No way I am driving in the Pennsylvania/ West Virginia snow with "brakes" that may or may not work.
 

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You're towing 40,000 lbs. commercially with a 3500 and you're worried about brakes? :)
 

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I had to bypass my ITBC and install a Prodigy P-2. You use all the wires under the dash except the dark blue wire, you run a new blue wire back to the factory 7 way at the bumper, cut the dark blue wire in the factory loom at the plug and and splice in the new dark blue wire to the dark blue wire going to the plug. Also when you power up the aftermarket controller at the fuse box using the factory supplied aftermarket trailer brake controller wire and put the ring attached to the wire onto the stud on the outside of the fuse box there will be a wire already on that stud(same size ring on the wire), thats the power for the factory controller, as per GM, you must remove the that wire from the stud, this will give you the "Service Trailer Brakes" message on the DIC, it is not a stored "code". It senses the open circuit and gives the message, no way around this, maybe the pcm can be reprogrammed to ignore the open circuit, maybe not. Once you hit the DIC button the msg goes away and doesn't come back until you shut the truck off and restart. If you do some searching on the net you will find the instructions to do this as very very few people are aware of how to bypass the ITBC properly and don't let anyone tell you it can't be done or shouldn't be done as the factory ITBC does not support electric over hydraulic brake actuators and some actuators are not easily tricked by the magnets or the e/h adaptors. Oh by the way my setup, P-2 controller, Dexter 1600 actuator, Dexter Hydraulic Disc trailer brakes, works outstanding.
 

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I have two studs with a wire on each. Which one do I take off and put the aftermarket wire one? The stud towards the fender, or the stud towards the engine?
 
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