Integerated Brake Control Failure

roguejason · August 6, 2008

I just wanted to pass along my findings. I have a 2008 GMC Sierra 1500 with the Integrated Brake Controller. I was having the issue where the trailer was not detected when plugged in. I would just get the ----- lines for output on the DIC. I had no problems with this trailer and another vehicle with a Prodigy P3 brake controllers.

It turned out that the problem was that the electric brakes on the trailer were wired in series. This was giving me ~3.8 Ohms resistance. When we rewired the trailer brakes in parallel, the resistance dropped to ~1.2 Ohms. Now when we plug in the trailer plug to the Sierra, we get the "Trailer connected" message and the IBC works just fine.

Jason

tomdually · May 27, 2014

I have a 2008 Chevrolet Silverado 1 ton dually. The electric brakes have not been functioning correctly for the last 3-4 months. I have checked the connectors and they appear ok. I did some research and discovered GM has a tech bulletin out,TB-09-05-22-004 to remap the IBC.

TECHNICAL
Bulletin No.: 09-05-22-004
Date: November 05, 2009
Subject: No "Trailer Connected" Message on Driver Information Center (DIC) at Startup When Trailer is Connected (Reprogram ITBCM)
Models:
2007-2008 Chevrolet Silverado
2007-2008 GMC Sierra
Equipped with Integrated Trailer Brake (RPO JL1) Condition
Some customers may comment that when they connect their trailer, with the engine off, and after they start the engine, the Trailer Connected message is not displayed on the DIC. With the engine running, if the trailer connector is cycled, the vehicle will detect the trailer and display Trailer Connected. This concern should only affect trailers equipped with trailer brakes

on a single axle.
Cause
The trailer brake control system is only compatible with trailers equipped with electric trailer brakes. The system will not work or detect trailers equipped with any other types of brakes such as surge, air or electric-over-hydraulic trailer brake systems. When a trailer is connected, the Trailer Brake Control Module (TBCM) performs a test to determine if the trailer is equipped with electric trailer brakes. If the trailer wiring or electric trailer brake magnets have additional resistance (caused by poor connections, corrosion, improper splices, etc.), the TBCM may not be able to detect the trailer.
Correction
A revised calibration has been developed to address these issues. Reprogram the Integrated Trailer Brake Control Module (ITBCM) with updated calibration files using the TIS2WEB Service Programming System (SPS) application. Refer to SI and Service Programming System (SPS) documentation for programming instructions, if required. Refer to Trailer Brake Control Module Programming and Setup in SI.

I had this bulletin completed and on the initial start up of the truck I get the trailer connected message, however, if I turn off the truck and restart I do not get this message. I measured my trailer brake resistance at ~ 3 ohms. The trailer is a 2008 Carriage Carri Lite (it's not lite) and have not experienced any problems until now. Would it be a fix to wire the brakes in parallel basically cutting the resistance in half. My dilemna is why should I need to do this if there hasn't been a problem for 6 years. One other thing is your trailer a single or dual axle?

Mike

gmtech4 · May 28, 2014

I have a 2008 Chevrolet Silverado 1 ton dually. The electric brakes have not been functioning correctly for the last 3-4 months. I have checked the connectors and they appear ok. I did some research and discovered GM has a tech bulletin out,TB-09-05-22-004 to remap the IBC.

TECHNICAL
Bulletin No.: 09-05-22-004

Date: November 05, 2009

Subject: No "Trailer Connected" Message on Driver Information Center (DIC) at Startup When Trailer is Connected (Reprogram ITBCM)

Models:

2007-2008 Chevrolet Silverado

2007-2008 GMC Sierra

Equipped with Integrated Trailer Brake (RPO JL1) Condition

Some customers may comment that when they connect their trailer, with the engine off, and after they start the engine, the Trailer Connected message is not displayed on the DIC. With the engine running, if the trailer connector is cycled, the vehicle will detect the trailer and display Trailer Connected. This concern should only affect trailers equipped with trailer brakes on a single axle.

Cause

The trailer brake control system is only compatible with trailers equipped with electric trailer brakes. The system will not work or detect trailers equipped with any other types of brakes such as surge, air or electric-over-hydraulic trailer brake systems. When a trailer is connected, the Trailer Brake Control Module (TBCM) performs a test to determine if the trailer is equipped with electric trailer brakes. If the trailer wiring or electric trailer brake magnets have additional resistance (caused by poor connections, corrosion, improper splices, etc.), the TBCM may not be able to detect the trailer.

Correction

A revised calibration has been developed to address these issues. Reprogram the Integrated Trailer Brake Control Module (ITBCM) with updated calibration files using the TIS2WEB Service Programming System (SPS) application. Refer to SI and Service Programming System (SPS) documentation for programming instructions, if required. Refer to Trailer Brake Control Module Programming and Setup in SI.

I had this bulletin completed and on the initial start up of the truck I get the trailer connected message, however, if I turn off the truck and restart I do not get this message. I measured my trailer brake resistance at ~ 3 ohms. The trailer is a 2008 Carriage Carri Lite (it's not lite) and have not experienced any problems until now. Would it be a fix to wire the brakes in parallel basically cutting the resistance in half. My dilemna is why should I need to do this if there hasn't been a problem for 6 years. One other thing is your trailer a single or dual axle?

Mike

dont you dare mess with your trailer brake wiring ,,,

who is the last question to ? 6 yr old thread you may not get an answer

tomdually · May 28, 2014

Thanks Govtech4,

I wasn't real keen on touching my trailer wiring. I am still having a problem with my trailer brakes, I want to exhaust all avenues before I have GM install a new IBC module for $166 plus....plus....plus.

Any suggestions?

sdeeter19555 · May 28, 2014

If it was me, I would be tracing out the trailer wiring and scrutinizing every connection for corrosion...and further, I'm aggressive enough, I'd rewire the trailer just to make sure...but that's just me.

tomdually · May 29, 2014

Thanks for the advice. Decided to crawl under and found another connector above the spare tire. Sprayed it with contact cleaner, tried a reconnect to the trailer and received the trailer connected message each time after 6 restarts. I wish I had found the connector the other day before spending $67 at the dealer for nothing. When I think back, makes sense because we first lost the brakes during a dirty snowstorm. The connector would sit in any accumulation above the spare, not sure why they hid the connector up there. Well live and learn. We'll be testing out the system on our trip downeast.

Thanks again.

sdeeter19555 · May 29, 2014

The best bet would be to remove the connector and solder every connection...I've done that to every trailer I have owned.

I found that the majority of trailer braking wiring is connected using Scotch Loc-type connectors, and those cause nothing but headaches as well...remove the Scotch Loc-type connectors, and most of the problems will either be fixed or will never arise.

Sent from my SAMSUNG-SM-G730A using Tapatalk