Air Brake Antilock problems of the 2003 GMC Envoy

While traveling at or less than 35 mph, on bright sunny day and on dry pavement vehicle would not stop, brake pedal went to the floor. Let it up and pressed it to the floor again without success. On third attempt jammed the pedal to the floor and the entire car locked up. The steering wheel wouldn't turn, at least one wheel locked, hit the car that was stopped at the stop light. Even after stopping only the service engine check light and the stop engine light illuminated. The brake pedal remained to the floor , and I couldn't not shift into park until after jamming on the pedal several times. 9000 in damage to the vehicle, including the frame had to be pulled, and yet the airbag did not deploy. 4ooo miles to the other vehicle. No injuries.

Purchased 2003 GMC Envoy slt on 11/30/2002. Service airbag light came on as I was driving the vehicle off the lot. Returned to dealer for repair. Dealer said it was a loose wire in the sensor. One month later service airbag light came on again. Returned it to dealer, could not determine problem so they replaced the passenger side airbag. Service air bag light is on again. This is the third time. Also have had intermittent problems with the brakes. When approaching a stop light have had instances where the car will not stop, and the brake pedal is to the floor this has happened 3 times. Took it into the dealer and was told this is the way the brakes function on this vehicle????? have had intermittent problems with the 4 wheel drive. The lights on the 4 wheel drive indicator will flash from 2hi all the way to 4 whl drive without every touching the control. Extremely disappointed in this vehicle for the cost and unfortunately have a 4 year lease. Will not recommend or purchase another GMC product.