Going up a 20% grade on a 90 degree turn at less than 15 miles an hour, vehicle looses all control. it takes 5-10 seconds to recover and sometimes slides back down the hill. dealer has attempted four repairs with test drives after each repair. dealer has notified gm of safety hazard. gm rep. is aware of other escalades with same problem and refuses to admit it as a safety issue. says engineers are working to release a new software program soon and not to drive vehicle unless disengaging stabilization system every time vehicle is driven.