Hydraulic Power Assist Steering System problems of the 2003 Chevrolet Trailblazer

While backing out of my driveway the steering became very hard and stiff when I tried to turn left. On the same day, while making a left turn, the steering wheel became stiff again and I had trouble turning. When parking at work, I could not turn left or right without first putting serious effort into turning. Might be a bad steering pump, but most likely rack and pinion issues. Also, I checked the power steering fluid level and it was low. Steering failure may lead to a very serious accident. I have an appointment to see the car dealer about this since this is most likely covered under gm warranty.

While driving at highway speeds vehicle suddenly steered off to the left and hit a tree. Consumer had no control of steering. Please provide any further information.