This post got tied up with another post on the Tow Vehicle section so I am starting it up here where it is more appropriate.My truck-'09 Silverado 2500 with integrated brake controller.About 2 1/2 weeks ago I got a "service trailer brakes" warning on my DIC.Not a trailer problem. I have power to everything except brake wire.I took it to the dealer and they told me it was the brake module. They didn't say which module though. They said it was on back order and they would have it by the end of last week. Called today and no part. I had OnStar do a diagnostic for me.It came up as ABS/Traction Control fault. Code C0131.I called another dealer's parts dept and asked for the ABS brake control module.This parts guy then filled me in and told me that there isn't a single dealer in the country that has this part in stock. Every dealer is waiting on GM.I have a trip coming up next week to pick up a tractor and I have no trailer brakes.Looks like I will have to buy an aftermarket controller to hook up to by pass the factory system so I can make this trip.How the heck do you let your stock deplete to zero??

I had the same problem, my dealer took the part needed from a new vehicle on the lot, back on the road within an hour, my truck was,still under warranty though. Hope your issue is resolved soon, have a safe trip...

"How the heck do you let your stock deplete to zero??"By using the cheapest bidding vendor and then that vendor can't or doesn't produce acceptible parts.

I installed a Prodigy last fall after dealing with the IBC issue on and off for two years. The issue was diagnosed as Electronic Brake Control Unit AND ABS system faults. The ABS system was getting imput signals but no output signals were being found. Therefore, the IBC was essentially disabled. IF they could have found the EBCU, the cost was about a grand, and there was no guarantee offered that replacing that unit would fully solve the problem. There were Technical Service Bulletins that essentially read if Step A (the EBCU) does not resolve the issue, go on to step B, C, D etc until fully resolved. I said the heck with that. I disabled and bypassed the IBC with the Prodigy. I do continue to get the "Service Trailer Brakes" message on the DIC, but I just hit the DIC function button and it's gone until the next time I cycle the key. The Prodigy works great and down the road I go.):

msjdbman wrote:I installed a Prodigy last fall after dealing with the IBC issue on and off for two years. The issue was diagnosed as Electronic Brake Control Unit AND ABS system faults. The ABS system was getting imput signals but no output signals were being found. Therefore, the IBC was essentially disabled. IF they could have found the EBCU, the cost was about a grand, and there was no guarantee offered that replacing that unit would fully solve the problem. There were Technical Service Bulletins that essentially read if Step A (the EBCU) does not resolve the issue, go on to step B, C, D etc until fully resolved. I said the heck with that. I disabled and bypassed the IBC with the Prodigy. I do continue to get the "Service Trailer Brakes" message on the DIC, but I just hit the DIC function button and it's gone until the next time I cycle the key. The Prodigy works great and down the road I go.):Good to know that my "Plan B" is going to work.I couldn't believe how hard it was to find info on this through google searches.Tons of pages with people complaining about the problem, but almost nothing on solutions or even giving locations where the different modules were located.I managed to find this out for '09 Silverado trailer brake problem:Main components, pressure sensor switch on right side of master cyl, ABS module is located on the frame rail under the drivers door, integrated trailer brake control module is located on driver side frame rail over the axle, integrated trailer brake controller relay is located on driver side frame rail also, connected by a wire to the integrated brake control module. They are about 10" away from each other.

A wheel speed sensor fault in the truck will throw all those faults. Basically kills power to ABS, Traction Control and trailer brakes. I think its dangerous that the programing kills the power to the trailer brakes but it's been 8 years with Intergrated controller from factory and as far as I know no programming change.

GM Brake Controller Fault | Good Sam Community

21 Replies

NJRVer
Explorer
Nov 20, 2016
Trailer cord is fine.
This is definitely an internal problem with the truck's braking system.

I have never been in the position since this happened to actually know for sure, I believe I have no ABS.
deltabravo
Nomad
Nov 20, 2016
Like posted above, part of the problem could be a loose fitting trailer cord to the truck plug.

I also had the problem, and asked a cargo trailer dealer about it when I happened to be shopping, and he described the inferior pigtails that some cord manufacturers produce.

I bought a new pigtail and verified it fit tight in the truck plug, then installed it. Problem solved.
If I recall correctly, it was a Pollak brand cord that I bought.
NJRVer
Explorer
Nov 18, 2016
I will get the IBC hooked back up.
I don't like the warning chime and message that always pops up every time I start the truck.
hawkeye-08
Explorer III
Nov 17, 2016
Now that the part is available, are you going to spend the big bucks to see if it fixes the problems or just stay with aftermarket controller?

I had a P3 controller in previous rig and sold it when new truck was purchased with IBC. Sometimes I wish I had the P3 still in case of issues with IBC..
NJRVer
Explorer
Nov 16, 2016
Wow!
Since July and Chevy dealer called today to say the brake control module that has been on back order just came in.

Only took 3 1/2 months for GM to get them.
trail-explorer
Explorer
Aug 24, 2016
I love my ITBC. ANything else is inferior once you tow heavy trailers with an ITBC. Why do I like them better when towing heavy? They operate the trailer brakes seamlessly and in full unison with the amount of truck braking applied.

It's also a known problem that some manufacturers of trailer pigtails don't make their plug diameter on teh end of the pigtail the proper diameter, so they fit really loose in the truck OEM truck plug.

I had ongoing "check trailer wiring" messages. Someone mentioned the loos fitting plug, and I said "yeas, it's really loose fitting." He said "change the trailer pigtail to Pollak brand pigtail, which fit better.
That solved my problem.
NJRVer
Explorer
Aug 21, 2016
BenK wrote:
Am curious, does your brake pedal switch look like the below images?

This is the key to having an after market trailer brake controller
lead the trailer brakes before the TV's brakes ever get turned on

GMBrakeSwitch brakeswitch

These pics for my reference for next discussion on trailer brake controller
and how the GM is different with less than 0.010" travel to turn on
the brake lights

Jframpey wrote:
Hmmm, i recently replaced the brake light switch (on the brake pedal) after getting a cruise control error - After an internet search told me that this was the probable culprit. I have a 08 2500 chevy - I had no issues with the IBC that I know of, but I don't recall towing while I had the issue either.

Changing the brake switch $35 fixed my problems... I took the old brake switch apart after the repair and found it gummed up with grease (someone was overzealous with it during assembly I guess. Anyway I found that the switch had two sets of contacts - one normally open and one normally closed. Check yours out - maybe its the culprit.

Well as luck would have it, left on my trip and ended up having the brake pedal switch go bad.
Was checking my mirrors and saw my trailer brakes smoking along with the drag on my truck.
Turns out the aftermarket controller I hooked up was taking a read from the brake wire thinking I was hitting the brake pedal and activating the trailer brakes.
What a fun ride I had down Rte 13 through Delmarva and all the traffic lights.
I had to hit the brakes but then take my foot and lift my brake pedal to get the controller to release the trailer brakes.
Hats off to Boyd Chevy in Emporia for taking me in with no appointment Monday and putting the new pedal switch in.
Still no parts from GM for the original problem with the ABS Control Module which killed power to my trailer brakes through the factory controller.
wingsfan20
Explorer
Aug 09, 2016
I had a similar instance happen when I had Shocks installed on my 2500. The installer had accidentlly hit the controller connector to the master cylinder and caused it to come off. i got the trailer message on DIC. Checked and reinstalled connector to master cylinder and alarm on DIC went away.
NJRVer
Explorer
Aug 08, 2016
I haven't taken my switch out, but it does look similar to that except black plastic.

I hooked up an econo DrawTite controller this afternoon so now I have trailer brakes again.
I really hated having to cut that factory brake wire back at the 7 pin plug.:M
BenK
Explorer
Aug 08, 2016
Am curious, does your brake pedal switch look like the below images?

This is the key to having an after market trailer brake controller
lead the trailer brakes before the TV's brakes ever get turned on

GMBrakeSwitch brakeswitch

These pics for my reference for next discussion on trailer brake controller
and how the GM is different with less than 0.010" travel to turn on
the brake lights

Jframpey wrote:
Hmmm, i recently replaced the brake light switch (on the brake pedal) after getting a cruise control error - After an internet search told me that this was the probable culprit. I have a 08 2500 chevy - I had no issues with the IBC that I know of, but I don't recall towing while I had the issue either.

Changing the brake switch $35 fixed my problems... I took the old brake switch apart after the repair and found it gummed up with grease (someone was overzealous with it during assembly I guess. Anyway I found that the switch had two sets of contacts - one normally open and one normally closed. Check yours out - maybe its the culprit.