Strange Module?

[DA BIG ONE]

We are talking a 99burb here, inside the jack and tire iron compartment there is a module way down near floor that has a slide out circuit board and its wrapped in a foam sheet I'm guessing for vibration protection, anyone know what this is for, or?

[diesel65]

I'll bet you the Sub has barn doors, how did I know?
The 97' thru 99' Suburban came with the door lock switch on the D-pillar to allow you to lock and unlock the other doors, Now if I were to lock the doors with that rear switch you will find that the barn door didn't lock because it is open, remember the contacts are on the door post.
That module senses that you closed the rear door then it will 20 seconds later lock the barn door.