WHILE DRIVING ON THE HIGHWAY, MY 2003 GMC SIERRA 2500 DISPLAYED A "REDUCED ENGINE POWER" WARNING ON MY DASHBOARD. MY VEHICLE LOST ALL SPEED CONTROL, DECELERATING FROM 65 MPH TO 20 MPH IN A MATTER OF SECONDS. I IMMEDIATELY PULLED OVER TO THE SIDE OF THE HIGHWAY AND SHUT MY TRUCK OFF. ONCE I RESTARTED THE VEHICLE, THE MESSAGE WAS GONE AND MY TRUCK WAS FINE. IT WAS A VERY SCARY INCIDENT NOT BEING ABLE KEEP THE RIGHT SPEED FOR THE CONDITIONS ON THE HIGHWAY. *TR