The official notice
Defect
Mercedes-Benz USA, LLC (MBUSA) is recalling certain model year 2016 SLK300 vehicles manufactured June 2, 2015 to July 14, 2015 and equipped with a nine-speed automatic transmission. The backup power supply for the ignition switch in the affected vehicles may not have been properly connected. As a result, if the vehicle is being driven and there is a loss of power from the main vehicle battery, the transmission cannot be shifted to "Park" nor can the electric parking brake be applied.
Safety Risk
In this situation, without the backup power supply, the only way to keep the vehicle from moving is to press the brake pedal. As soon as the driver attempts to exit the vehicle, the vehicle may roll, increasing the risk of injury.
Remedy
MBUSA will notify owners, and dealers will correct the ignition switch wiring and perform a software update, free of charge. The recall began on May 9, 2016. Owners may contact MBUSA customer service at 1-800-367-6372.