four wheel drive problem

If memory serves me correctly, your vehicle's 4WD system is driven electronically with automatic locking hubs. One thing im wonder is, are you certain your pushing the button at the appropriate times? Most newer vehicles will "shift on the fly" meaning, you press 4X4High and it will automatically switch in. To get it into low gear, the vehicle must be in neutral sitting at a dead idle.

First thing i would check are fuses. Under the hood is where it should be.. if its blown, its time to figure out why and repair the problem. If you purchased the vehicle used, there may have been a problem with the 4wd system and they disabled it by removing the fuse.

One thing to keep in mind is you will still be able to break the rear wheels loose without the fronts letting go. Meaning, you can spin the rear wheels on wet pavment and the fronts will remain dead. This is in 4WD HIGH. In 4Wheel Low, your steering will be less responsive and fight more, but will spin all 4 wheels equally (nearly).

So... check fuses and make proper repairs ~ Make sure your actully in 4wd and ready to go and if all else fails, take it to the GM dealer and spend the money to have them figure out what the problem is. I know 90% of dealers charge 65$+ an hour for diagnostic time, if you take it to an indipendent shop such as mine, you will likely find a more than capable technican with the proper OBD2 scan tool to retrive the data and find out whats wrong for alot less and alot of the time if you have it repaired there, the diag time could be absorbed into the costs of repair simply for letting them go ahead with it.. could be something simple, could be something major... but this is the place to start

to put my vehicle into 4wd low then you can be movin but to go back to 2wd you need to be stopped and in neutral I think. I know you can be moving and switch from 4wd high to 2wd hi.