If you do not go off road, just leave it in 4 high and you will be fine. You do not need to tap on the brakes since the GX has anti lock brake, just push the brake and hold it there and the electronics will do the tapping if necassary. DAC is mostly for off road use, you can play around it when there is no traffic, but I would not use it in the city. If you are going down a icy hill with multiply stop signs, try shifting into lower gear and use the engine braking. If you feel yourself skidding while starting off slowly down the hill, it may be time for new tires or get some snow tires, I would not shift into low or use the DAC in that condition. I believe the brakes still work when in DAC mode and you do not need to lock the center diff to engage the DAC.