NHTSA Complaint #10351096 — 2007 FORD FUSION

WHILE TRAVELING FROM CANYON TO NORRIS IN YELLOWSTONE NATIONAL PARK, I ATTEMPTED TO CONTROL THE SPEED OF THE VEHICLE MANUALLY WHILE CLIMBING A STEEP HILL, BUT FOUND IT IMPOSSIBLE. THE DESIRED SPEED WAS 45, WHICH IS THE MAXIMUM SPEED IN YELLOWSTONE. THE THROTTLE HAS A DELAY OF ABOUT ONE SECOND, SO IT IS CONTINUALLY 1 SECOND BEHIND THE COMMANDS OF THE DRIVER. THE RESULT IS THAT THE VEHICLE ALWAYS OVERSHOOTS THE SPEED BECAUSE THE DRIVER FIRST EXPECTS A RESPONSE FROM THE VEHICLE, BUT GETS NONE AND CONTINUES TO PUSH THE ACCELERATOR PEDAL FARTHER DOWN. WHEN THE VEHICLE REACHES THE DESIRED SPEED, THE DRIVER LETS UP ON THE ACCELERATOR, BUT THE VEHICLE CONTINUES TO ACCELERATE ACCORDING TO THE COMMAND 1 SECOND AGO. THE DRIVER THEN CONTINUES TO LET UP ON THE PEDAL BECAUSE THE VEHICLE HAS NOT YET RESPONDED TO THE COMMAND TO REDUCE RPM. THE TRANSMISSION SHIFTS UP WHEN THE DRIVER LETS OFF THE ACCELERATOR. THE VEHICLE THEN UNDERSHOOTS THE DESIRED SPEED AND THE DRIVER PUSHES THE ACCELERATOR DOWN AGAIN. THE VEHICLE AGAIN DELAYS ITS RESPONSE AND THE TRANSMISSION ADDS AN ADDITIONAL DELAY OF ABOUT 2 SECONDS. THE NEXT OVERSHOOT IS WORSE. THIS OSCILLATION CONTINUES UNTIL THE DRIVER GETS FRUSTRATED AND SETS THE SPEED CONTROL. THE SPEED CONTROL STILL FAILS TO MAINTAIN SPEED WHEN THE GRADE CHANGES RAPIDLY, BUT THE SLOW DOWN IS MUCH LESS AND IT RECOVERS IN A COUPLE SECONDS AND MAINTAINS SPEED THE REST OF THE WAY UP THE HILL. THE DRIVER THEN HAS TO RIDE THE BRAKES ON THE WAY DOWN THE OTHER SIDE OF THE HILL IN ORDER TO MAINTAIN SPEED, WHICH RELEASES THE SPEED CONTROL. THE DRIVER THEN HAS TO SET THE SPEED CONTROL WHEN THE VEHICLE REACHES THE LEVEL AGAIN. IF THE DRIVER LETS THE VEHICLE CONTINUE TO ACCELERATE DOWN THE HILL, THE TRANSMISSION WILL EVENTUALLY DOWNSHIFT AT ABOUT 48 MILES PER HOUR, BUT CONTINUES TO SLOWLY ACCELERATE. CONTINUALLY TRYING TO CORRECT FOR THE LACK OF CONTROL OF SPEED RESULTS IN AN EXCESSIVE DISTRACTION AND CONTINUALLY TAKES THE EYES OF THE DRIVER OFF THE ROAD. *TR