I don't know much at all about my transfer case or drivetrain, except for the engine being similar to my z28 m6. I just bought this loaded 2003 suburban 1500 a couple weeks ago. Still trying to study about it. As I understand it, it is a full-time 4wd transfer case, but there were two options that year. They told me this at the junkyard. I am trying to figure out accurately how my transfer case works. There are three buttons I believe, when I click the top one a light comes on for tc off. Partly what I'm wondering is, am I correct in assuming I have full-time 4wd with open differentials front and rear with traction control achieved by abs pulsation, instead of LSD's? Am I correct?