First off, I am so sorry to be asking yet another question about the TRAC/ALSD/etc. It probably is a dumb question, but I figured it dumber to not ask.
I understand when the truck is in 2HI, the TRAC tries to keep the tires from spinning at different rates via braking, but also regulates power from the engine. ALSD does this same thing but with unregulated power when the VSC Off button is pressed. When the truck is in 4HI, the base mode is TRAC which is actually ALSD (unregulated power!). (Assuming this is correct, I'll keep moving along.)
My question is this; starting with the TRAC in 2HI, does the system try to keep all 4 wheels spinning at the same rate? Or is this only happen with the rear two wheels while in 2HI? Same thing with ALSD, all four or just the two "with power"? This would essentially act as though a LSD was in Diff C in my awesome drawing, but everything else is open diffs.
Then would 4HI act as though all four tires are at the same speed (a pretend LSD is at Diff A to keep the front two wheels together, LSD at Diff C to keep rear wheels spinning together, and LSD at Diff B to keep the front and back spinning at the same rate)? Or does the system act where a LSD is replacing Diff A and Diff C, but they are independent of each other? If the case is the latter, does the system suck when both the front wheels or both the back are on, let us say, ice?
The reason for this question is that the other day I spun my rear tires while in 2HI on an icy corner, but no light say "TRAC being used!!!" came on which, to my understanding, should have. So if both rear tires slip, but spin at the same speed, I could see my predicament the other day. But I want to know now if the same thing would have happened in 4HI. If Diff A and Diff C are uncoupled, it seems like the same thing could have because the rear tires were spinning evenly and the front tires were spinning evenly.
I would go out and try it but it was on a busy intersection and the roads are all pretty well cleared up now. I hope I am clear enough to get someone to explain it to me, but if not just shout! Thanks!