Tl* the contact owns a 2017 lincoln mkx. the contact stated that the vehicle was designed to have a tow mode, which would allow the vehicle to tow. while the 39,000 lbs vehicle was towing a 50,000 lbs rv, the vehicle's battery failed. the vehicle was designed to go into park mode, which locked all four tires when the battery failed. once the vehicle went into park mode, it caused the vehicle to be dragged by the rv for several miles. the contact stated that the park mode feature should not occur since the vehicle was in neutral when in tow mode. the contact called camelback ford (1330 e camelback road, phoenix, az 85014; 602-635-7551) and was informed that the vehicle functioned as expected according to the design of the feature. the manufacturer was made aware of the issue, but the contact did not receive a response. the approximate failure mileage was 22,000.