# 2008 chevy duramax brake controller



## jck (Sep 7, 2009)

I bought a trailer with electric brakes on it and I think they had it wired wrong. I plugged it in and I got a check trailer wiring message on the instrument panel. sure enough it is wired wrong, fixed all that and now I can not get any output from my intergrated brake controller and I still get the check trailer wiring message even when I dont have a trailer hooked up. I did find a blown left brake light fuse but that is it. Any suggestions??


----------



## Old Timer (Jan 10, 2009)

*Trailer Wiring*

After plugging in the trailer, when you turn on the ignition, the DIC should show Trailer Connected at first, then show output. My guess would be that you still have a problem with your trailer wiring or not getting a good ground which is a common problem. The blown fuse is not the problem, you would only lose the one light.


----------



## seabo (Jun 29, 2006)

my 08.after a rain or carwash the warning comes on until the water drys, no real problem. a bad ground or blown TRAILER brakelight fuse will cause the controller not to work, no power to brake lights, no power to electric brakes.


----------



## jck (Sep 7, 2009)

Old Timer said:


> After plugging in the trailer, when you turn on the ignition, the DIC should show Trailer Connected at first, then show output. My guess would be that you still have a problem with your trailer wiring or not getting a good ground which is a common problem. The blown fuse is not the problem, you would only lose the one light.


I plugged the truck into my camper with trailer brakes and everything works like it should just no brakes or no output from the brake controller. The DIC does not do anything when I plug or unplug the trailer. It acts like it does not sense a trailer back there. Before when I would plug and unplug my trailer it would notify me on the DIC. Everything on both trailers work except brakes.


----------



## Old Timer (Jan 10, 2009)

Just finished reworking the trailer brake system on my 08. The DIC came up to Check Trailer Brake System. All lights worked but no trailer brakes. Fixed by installing a new brake pressure sensor (located on the MC) and a new TCBM (trailer brake control module) located on the frame rail under the drivers side.
The module can be unplugged and sent in to rebuild, but I didn't try that.
Everything in the vehicle brake system will work without it while it is getting repaired.


----------



## jck (Sep 7, 2009)

Old Timer said:


> Just finished reworking the trailer brake system on my 08. The DIC came up to Check Trailer Brake System. All lights worked but no trailer brakes. Fixed by installing a new brake pressure sensor (located on the MC) and a new TCBM (trailer brake control module) located on the frame rail under the drivers side.
> The module can be unplugged and sent in to rebuild, but I didn't try that.
> Everything in the vehicle brake system will work without it while it is getting repaired.


I plugged the truck into my camper as stated above because I know everything on it works like it should. Did you do this yourself or did the stealership do it. If you dont mind me asking what did it cost you to have this fixed. Sounds like this may be my problem. What caused you to have to fix the braking system? thanks for the reply


----------



## Old Timer (Jan 10, 2009)

First happened without the trailer (Check Trailer Brake System) in DIC. Went to dealer and they did the diagnostics and changed the BPS for a total of $285.
($85) for the sensor. Online you can buy a new module for about $300.
About a month later was pulling a trailer and after about a 2 hr. pull lost brakes.
Went back to dealer and they changed the BPS and also the TCBM and for some reason covered it with warranty. Under 5 years on the truck. Module is easy to change but the BPS change you will have to bleed the MC. Hope this helps.
Good luck.


----------

