Put it in 4h to drive through some mud now I can't get it back into 2h. Have pushed the buttons both the 2h and auto, moving, in neutral, in drive everything... stuck in 4H and drives hard on the road.

as a cam sensor. replaced crank sensor, was told it could cause that also. Now it wont start at all. cam sensor discontinued and im packed up to go on vacation. isnt there some thing i can do to fix this thing. I'm desperate to say the least

I have taken the time to check the grounding the fluid and the connections. It still will not shift into 4 wheel drive. If I stop and put it in nutural I can get the 4 low to engage but the 2 wheel light up as well. very loude shift but I am not confident that it is really engaged.
also can not get the transfer case to register nutural on the selector.

my 2003 avalanche keeps going dead every few days i have put in a new battery and i am still having the same problems any ideas on how to fix this

Hi there:

How should i know if the previous owner performed a modification on the computer´s program in order to gain gas mileage or to achive some more power ? He instaled big tires on it,

I´ll aprecite your advise, thank´s