Factory integrated brake controller not recognizing trailer.

[swathdiver]

As I'm progressing through this dillema, trying to diagnose the integrated system, I keep getting this...

View attachment 377604

At the same time I have this...

View attachment 377605

If there's a fault, would there be a code set?

Did this trailer work on this truck before? There are some designs of trailer brakes that do not work with the ITBC.

Is your Trailer Brake Control Module part of the Fuel Pump Control Module or are they separate computers?

From the main menu you can select the last option for the Tech-2 to query all installed modules looking for trouble codes and when complete will list them. There may also be failure snapshots, I forget the term, brief recordings showing the what the sensors were doing when the code set.

 

[Fless]

From the main menu you can select the last option for the Tech-2 to query all installed modules looking for trouble codes and when complete will list them. There may also be failure snapshots, I forget the term, brief recordings showing the what the sensors were doing when the code set.

Freeze frame?

 

[swathdiver]

Freeze frame?

I can't remember... failure records maybe?

 

[dkad260]

Current progress...

I made a test light to plug into the 7-pin at rear of Yukon.

With the ignition on, engine off, Inget a single dim flash upon connecting. The voltage is right about 3VDC. I get one flash each time I connect the light, the light has about 2.5 ohms.

I have continuity from the rear of the 7-pin to both the relay, and the 47 pin connector at the FPCM...both leads measure about .25 ohms.

I have continuity from the yellow/black SSR enable lead from the relay to the FPCM.

Still no trailer recognition.

 

[swathdiver]

Current progress...

I made a test light to plug into the 7-pin at rear of Yukon.

With the ignition on, engine off, Inget a single dim flash upon connecting. The voltage is right about 3VDC. I get one flash each time I connect the light, the light has about 2.5 ohms.

I have continuity from the rear of the 7-pin to both the relay, and the 47 pin connector at the FPCM...both leads measure about .25 ohms.

I have continuity from the yellow/black SSR enable lead from the relay to the FPCM.

Still no trailer recognition.

And you double checked those J-Case fuses at 63 and 68? And you followed this testing from the original stored code?

 

[dkad260]

I did check the fuses, those are good.

I had to wait on testing the earlier fault as I didn't have the proper test probe for the small pin sockets.

I will conduct that troubleshoot this weekend.