NHTSA Complaint #10608108 — 2011 LEXUS GX460

1.WHEN GOING DOWN HILLS IN D GEAR, UPON REACHING 55-60 MPH, WHEN THE BRAKE IS TAPPED TO SLOW DOWN THE TRANSMISSION SUDDENLY SHIFTS DOWN FROM 6TH GEAR TO 4TH GEAR AND THE RPM SPIKES TO AROUND 4,000 RPMS. 2.THIS PROBLEM WAS REPORTED TO THE SERVICE DEPARTMENT OF BERLIN CITY AUTO GROUP, IN PORTLAND, MAINE, ON OCTOBER 13, 2013. THE CAR WAS DRIVEN BY A MECHANIC ON A FLAT ROAD (EVEN THOUGH TOLD THAT ANY TEST NEEDED TO BE ON A HILL WHERE SPEEDS OF 55-60 MPH COULD BE REACHED); THE REPORT WAS THAT EVERYTHING WAS FINE; NO PROBLEM. 3.ON OCTOBER 17, 2013 A LEXUS AREA REPRESENTATIVE DROVE THE CAR WITH A COMPUTER CONNECTED TO IT AND THE SAME PROBLEM AS NOTED IN NUMBER 1 WAS OBSERVED. THE THROTTLE BODY WAS CLEANED AND REPLACED ON TWO SUBSEQUENT VISITS; PROBLEM NOT SOLVED. ANOTHER LEXUS GX 460 WAS BROUGHT TO THE AREA AND WITH A COMPUTER HOOKED TO IT TESTS WERE MADE; IT DID NOT AUTOMATICALLY SHIFT DOWN FROM SIXTH GEAR TO FOURTH GEAR. ON JUNE 26, 2014 THE CAR WAS TAKEN TO THE DEALER. THE SERVICE ADVISOR SAID IT WOULD BE TESTED TRAVELING DOWNHILL AT 50-60 MPH. LATER I WAS INFORMED NO PROBLEM WAS DETECTED. MILEAGE RECORDS SHOW THERE WAS NO TEST RUN MADE. AN ACCELERATOR SENSOR ASSEMBLY WAS REPLACED, APPARENTLY ORDERED SOME MONTHS AGO AS A POSSIBLE SOLUTION THE PROBLEM.THE NEW PART MADE NO DIFFERENCE, THE PROBLEM IS GETTING WORSE, AS THIS AUTOMATIC DOWN SHIFTING FROM SIXTH GEAR TO FOURTH GEAR NOW HAPPENS AT LOWER SPEEDS, SUCH AS BETWEEN 40-50 MPH. 4.THIS PROBLEM CAN BE VERY DANGEROUS IN THE WINTER TIME, WITH SNOWY, ICY AND SLIPPERY ROADS WHENEVER THERE IS A DOWN SHIFTING FROM SIXTH GEAR TO FOURTH GEAR AND THE VERY SUDDEN SURGE IN RPMS. BECAUSE OF THIS SUDDEN, ABRUPT DOWN SHIFTING THERE IS THE HIGH RISK OF A SUDDEN LOSS OF CONTROL OF THE VEHICLE; THIS DEFINITELY IS A LIFE AND SAFETY ISSUE PLUS A DECREASE IN MPG. *TR