We have a new 2004 Blazer. While driving at 65 mph the odometer and speedometer suddenly stop and the parking brake warning light comes on. The vehicle drives normally until we come to a stop and then when we try to accelerate the engine races and it feels as though we are driving with the brake on. The next day everything is fine so the dealer cannot find a problem. This has happened twice in the last 3 months. Any ideas. Thanks.