I have a 2017 Jeep Renegade with 21K miles (yes, I have low mileage). The Service Passive Entry System message popped up on my dashboard, the dealer ask that I bring it in for diagnostic $189.00, so I looked it up on line and found this forum. I read through all the troubleshooting, the best that worked for me was remove the negative battery for a few minutes (these cars are computerized) to reboot the system and it work. It won't be the key fob battery because I've experience that a few years back, which has a notification indicator of its own. another option was to start the car, without having it run... but that option didn't work for me. Thank you for this forum and for the person who said "think people, think, these cars are computerized---- reboot! 
