GM Integrated Brake Controller (ITBC)

[downslope]

In the owner's manual for 2008 it says for trucks with the heavy duty trailering package the fuses for the RED battery feed and BLUE trailer brake feed are installed in the underhood electrical center, but the wires are not connected. I'm not getting any brake output at the 7-pin connector, and no output is displayed on the dashboard readout. I checked the 15 amp fuse for the brake output and it's installed and not blown. The lighting circuits are working OK. Do I need the RED 12V circuit if the truck has the auxillary battery option?

Do I have to connect the blue circuit somewhere, and if so where would that be? Or could there be a problem with the integrated controller. Have these factory integrated GM controllers been known to be troublesome?

 

[Diamondpilot]

Sounds like a wiring issue from the factory or something not hooked up. GM has been doing this since the body style change in 07 and its been a pain compared to the way it was pre 07.

I do not know anyone with a GM ITBC but know about 15 with the Ford one and it works great. I have heard no issues with the GM one other than its not as user friendly due to its placement.

I would hook the red wire up to the battery post and see if you then get power. Here is some info on that.

2007 GM Trailer Brake Controller install

If that fails it would be time to take it to the dealer for warranty work.

Chris

 

[timswi]

I would take Chris's suggestion and see if you can indirectly push the power to the 7 pin connector.

if memory serves, my manual said that the trailer power wires were not connected at the factory, the must be connected by the owner. No big deal from what I could see, just attach the wires to the correct lug in the distribution box.

There's probably a reason for this, I just don't know what it might be.

I bought mine used, so mine were connected.

 

[Wooddust]

I went through similar issue only to discover the trailer plug was wired wrong...

 

[downslope]

I went through similar issue only to discover the trailer plug was wired wrong...

Wooddust, does your truck have the factory installed controller or aftermarket?

The brakes on this trailer work OK when connected to my friend's Toyota pickup, so I suspect the trailer is wired correctly.

The manual is a little confusing because I don't know when they are talking about the factory controller versus installing your own aftermarket. I think the info in Chris' link above was about installing a Tekonsha Brake Controller. I know that if you already have the integrated controller from the factory you have to disconnect that before installing something else.

You would think with an integrated system it would be good to go by just plugging in. It may be that a trip to the dealer is in order, but I wanted to use the trailer this weekend. It is only a little single axle 2900 lb GVW trailer, so I have been moving it around empty without the brakes working. Would it be OK to put 1,000 lbs on it and tow without the brakes; I would then be around 2,000 lbs total??

 

[timswi]

Wooddust, does your truck have the factory installed controller or aftermarket?

The brakes on this trailer work OK when connected to my friend's Toyota pickup, so I suspect the trailer is wired correctly.

The manual is a little confusing because I don't know when they are talking about the factory controller versus installing your own aftermarket. I think the info in Chris' link above was about installing a Tekonsha Brake Controller. I know that if you already have the integrated controller from the factory you have to disconnect that before installing something else.

You would think with an integrated system it would be good to go by just plugging in. It may be that a trip to the dealer is in order, but I wanted to use the trailer this weekend. It is only a little single axle 2900 lb GVW trailer, so I have been moving it around empty without the brakes working. Would it be OK to put 1,000 lbs on it and tow without the brakes; I would then be around 2,000 lbs total??

I've towed at least that much without brakes, although if you have them available on the trailer (which I didn't at the time, heavy utility SA trailer) don't get in a wreck or you'll be in a heap of trouble if the brakes weren't hooked up when you had them available. Doable, yes...Advisable, no.

 

[BruceWard]

You may have legal problems in your state but assuming you have a GMC Sierra 1500 or larger you should not have any issue with a 2,000 pound trailer without brakes. I have towed 4,000 pounds without brakes with mine and often two 8,000+ with brakes on both axles. With 3 or 4 thousand pounds the truck brakes work just fine.

 

[aczlan]

The manual is a little confusing because I don't know when they are talking about the factory controller versus installing your own aftermarket. I think the info in Chris' link above was about installing a Tekonsha Brake Controller. I know that if you already have the integrated controller from the factory you have to disconnect that before installing something else.

Look on the link that Chris sent for the piece where they talk about

Next, locate the wire that is hard to see, folded up between the fuse box and the fender. It may be well hidden. This is the wire that runs through the firewall, and supplies the power to the brake controller (the Red wire with black tracer). Put this on the stud. You will have to buy a metric nut to secure these wires to the stud, I think a 6 mm or 8 mm.

I would also verify that the wires to the back of the trailer are connected (as seen in the 2nd picture on the link Chris posted).

As I recall, there are some controllers that will not turn on until you have a trailer connected. Yours may be one of them.

Aaron Z

 

[Diamondpilot]

I just called a friend of a friend for ya. He has a 2010 GMC 2500 Gas with the ITBC and he said he had to do nothing to make his work. He did say he had to buy and install a Maxi-Fuse to make the charge function work for his travel trailer.

Chris

 

[downslope]

I just called a friend of a friend for ya. He has a 2010 GMC 2500 Gas with the ITBC and he said he had to do nothing to make his work. He did say he had to buy and install a Maxi-Fuse to make the charge function work for his travel trailer.
Chris

Thanks for talking to your friend. That's kind of what I figured, it should be ready to go as far as brakes and lights. Those wires in the pictures near the fender well are only for installing an aftermarket controller, they lead back to the stub wires under the dash. The wire in my truck is actually labeled aftermarket. Yes, you do have to activate the circuit for trailer charging and interior lighting, I guess they don't want 12 volts dangling around if you're not going to use it.

Since the truck is still under warranty I'll have to go back to Chevy to have them check the ITBC. It could just be moisture in the connectors but there is also a pressure transducer on the master cylinder that senses braking demand. The integrated controller also takes imput from the ABS system and I've gotten some error messages on the monthly reports via OnStar about ABS faults, so who knows, a wheel speed sensor could be bad or anything. It also continuously shows error messages on the dashboard display about low tire pressure even though I keep them at 50 psi when unloaded. I guess it wants you to run them at 65-70 psi all the time. Thanks again for all the info.