I drive 2002 yukon denali and was making a sharp turn when the front wheels lock. They wont turn, i finally got them to turn enough to back up out of the way. It looks like it has enough ps fluid

This is a sign that the CV joint is bad.

Can be many things. Check the cv joints first- will make sharp clicking noise especially when turning. Wheel bearing but it will be all the time and noise will increase with speed. Control arm bushes - shudder and noise when accelerating or when driving on road with an slight incline (up hill). If nothing obvious found take the car to an suspension specialist for evaluation and quote.

Do you have the vehicle in 4 wheel drive? 4 wheel drive is only meant for slippery conditions. It will act exactly as you describe if on dry surfaces.

Front Drive Axles Worn

Is this an all-wheel drive or 4 wheel drive. If it is it sound like you have the vehicle in 4 wheel drive.

memory has to flashed by the dealer

there is a shift lock solenoid that releases the shifter when the brake is applied.Check the fuse is not blown.The other thing is make sure the steering wheel has no backpressure on it.That will jam the ignition from turning.there is a cable running to the shifter in the column.

worn out hub bearing. do not drive anywhere but to get it fixed! Jack up grab wheel at 12 and 6 and rock it ,loose aint it.

Sounds like an issue with the awd system, best to have it checked out by a professional. There could any number of issues from the front wheels not disengaging to a CV problem.

Yup - you may need to get the grilles and such as well...