Can someone explain me as of what does the 4 wheel computer (which is for the ABS) located in the dashboard does to the ABS??

Are you asking about the ABS computer or the 4 wheel drive computer? As for ABS, you have speed sensors that watch you wheel speed in a panic-stop situation. These sensors communicate with the computer and if they relay that one or more of the wheels have stopped(locked-up), the brakes will be freed from the wheel so the lock-up condition doesn't occur. All this is done in fractions of a second over and over again. The fraction of a second that the sensors sense the wheel is moving lets the brakes work again. I've used mine in a couple of panic conditions and I feel my truck has been saved in those instances.
As for the 4x4 conputer, it talks to the main CPU and does things like sending signals to lock the front hubs(ADD) and insure that the truck is in 4wd before locking the rear diff(if you have one & haven't done the grey wire mod). It also sends signals to the 'idiot lights' on the dash board to let you know these sort of things are engaged. It probably does a few things that I haven't mentioned. I hope this helps. Bray <img src="/forums/images/graemlins/cheers.gif" alt="" />