Tesla will be contacting the owners of certain 2015-2016 Model X cars built prior to October 2016. These vehicles have been manufactured with steering racks that could fail.
According to the defect report, long term exposure to corrosive environments could cause the power steering gear assist motor bolts to corrode and weaken. If the bolts break and the motor moves, the transmission belt will slip on the gear housing causing reduced or lost power steering assist. The driver will still be able to steer the vehicle, but it will require more effort, especially at low speeds. If these bolts fail, the driver will likely hear significant noises, such as whining, screeching, or squeaking and should receive an audible warning or visual waning on the vehicle instrument cluster.
Owners receiving notices will be asked to return to their Tesla Service Centers to have the steering gear mounting bolts replaced with steel bolts with a corrosion preventative sealer. If the mounting bolts are found to be broken or break during removal, a new steering gear will be installed.