TL*THE CONTACT OWNS A 2010 TOYOTA SIENNA. WHILE DRIVING APPROXIMATELY 25 MPH THE SECOND REAR SEAT MOVED BACK AND FORTH WHILE TWO CHILDREN WERE SEATED IN THEM. ONE OF THE CHILDREN SUSTAINED AN INJURY TO HER LEG WHEN IT HIT THE REAR OF THE FRONT PASSENGER SEAT. THE CONTACT STATED SHE STOPPED THE VEHICLE WHEN SHE GOT A CHANCE TO CHECK THE CHILDREN. THE CONTACT HAD TO DRIVE ONTO THE EMERGENCY LANE WHENEVER THE FAILURE OCCURRED TO MAKE SURE THE PASSENGERS WERE NOT INJURED. THE FAILURE OCCURRED THREE TIMES. THE DEALER WAS UNABLE TO DUPLICATE THE FAILURE. THE CONTACT STATED THAT ON ANOTHER OCCASION, THE SEAT LUNGED FORWARD WITH A CHILD IN IT BUT HE WAS NOT INJURED. THE APPROXIMATE FAILURE MILEAGE WAS 2,800 AND THE CURRENT MILEAGE WAS 3,100.