From what i understand:
You have 2 ways in the Rams to communicate
The first is when your cell phone connects by bluetooth to the radio, which we all use
The 2nd way is through the 911 button on your mirror
Each Ram that has the 911 button, has its own phone modem,
( known as a Sierra Wireless module air card ) that modem is assigned to the VIN # of your Ram
It will only connect with a 911 operator
That same phone modem is also used by the other ASSIST button
To use the Assist button, you must have signed up for what is now called something like Uconnect Advantage or Uconnect Guardian, it may have a different name, but, it does have a Fee to use it,
Assist button will only connect you with Customer Care
To use the buttons on the mirror, you do Not have to have a cell phone any where around your vehicle
The Assist button:
Vehicles equipped with the Uconnect Access system feature will contain an ASSIST button on the rear view mirror. The ASSIST button will connect you directly to one of three important Uconnect Care centers for your assistance and support.
Roadside Assistance – If you get a flat tire, or need a tow, you’ll be connected to someone who can help anytime. Additional fees may apply. (see the Disclaimers section below for more detail)
Uconnect Care – In vehicle support for Uconnect Access System, Apps, and Features.
Vehicle Care – Total support for your Chrysler Group vehicle.
If you are getting the 911 error message
Something is likely wrong with the Air Card