Key is not detected

take it out of the purse. Your purse may be preventing it from being read by the sensor

My 300 was doing the same all I did was boosted the car off then I saw I had left the dome light on for a couple of days and the car battery was weak.. it started right up ..

2014 300 here. Did this today. Battery was pretty much dead I guess but the car didn't tell me that. Instead it told me "Key not Present" or some such. Jumped the car and all was good. Car info does not mention battery status. This is not a very smart car btw... especially the onboard assistant... "you can ask me Call John Smith". Word of warning: I couldn't get into my trunk to look for cables while the battery was down!!!

My daughter's Chrysler 300 has a post under the hood (covered by a red + ) that you can use to jump start the car without accessing the battery in the trunk.