People were forgetting to put their cars in park
Instead of physically moving the lever from one position to another, it resets to a center position in between uses. To put it in Park, drivers push it forward, regardless of what gear they're currently in. To put it in Drive, they pull backward. Simply by looking at it, there isn't an immediate indication of what gear is selected other than some small LED lights.
"unless due care is taken, drivers may draw erroneous conclusions about the status of their vehicles"
Currently, the cars deliver warning messages and sounds if the driver's door is opened while the engine is running and the car isn't in Park but, an investigation found, these measures "may be insufficient to deter some drivers from exiting their vehicles without selecting Park." In other words, people aren't paying enough attention to what the hell they're doing. At the same time, it's not too much to ask of Chrysler to make its cars less confusing.
So, Chrysler is reprogramming the cars with even more warnings, and an enhancement that will prevent the car from moving even if the driver fails to shift into Park. Chrysler also redesigned the shift lever in the Charger, the 300, and the Grand Cherokee "to address customer-satisfaction issues."
Correction: A previous version of this article misidentified the shift lever that was being recalled. The spinning dial gear shift used in many current Fiat Chrysler products is not being recalled.