Complaint-2005 Toyota highlander: Unsafe operation this vehicle has a "fly by wire" computer system that is causing hazardous unexpected engine stumbling, engine hesitation and erratic transmission shifting. The vehicle cannot always be eased into traffic and on one occasion when merging into interstate traffic the engine raced and down shifted so violently that the passengers thought we had been hit from the rear. An incident occurred while using the cruise control(at 70 mph). The engine raced, down shifted and the vehicle jumped forward before it could be controlled. Also, while on the interstate, without cruise control, I moved into the passing lane: The engine raced, downshifted and refused to accelerate. I could have been rear ended had the driver following not been alert. Engine speed can vary and shifting can occur at any time. When entering a garage or parking space the driver must keep firm pressure on the brake pedal, since the vehicle may decide to change engine speed and move forward. I have been informed that the computer can take control of the transmission, throttle and braking under computer anticipated rollover conditions. Imagine the driver's horror when attempting to avoid an accident to find that he is no longer in control of the vehicle. I have met with the Toyota dealer representatives, taken the vehicle in for repair(three times on record), taken test drives with the local Toyota tech and the Toyota district service manager and written E-mails to the Toyota web site all to no avail. I am told that the vehicle is designed to operate this way and nothing can be done. They did implement one tsb, but nothing changed. This has been occurring with the highlander and other Toyota models since 2004 and possibly before that date. I guess Toyota will wait for a catastrophic event before it takes an interest in correcting this poorly designed and hazardous system. My wife and I are afraid we may be among the victims of this hazardous vehicle.

- Nashville, TN, USA