Abstract: A system and method of selecting a modem for cellular communications while the vehicle is in a primary propulsion off state. The method includes: detecting a transition from a primary propulsion on state to a primary propulsion off state of the vehicle; after detecting the transition from the primary propulsion on state to the primary propulsion off state, measuring one or more cellular connectivity parameters for a plurality of modems included in the vehicle; based on the cellular connectivity parameter(s), selecting a modem of the plurality of modems; after selecting the modem of the plurality of modems, then turning off non-selected modem(s) of the plurality of modems, wherein the non-selected modem(s) include the plurality of modems other than the selected modem; and sending a selected modem indication to a remote server, wherein the selected modem indication indicates to the remote server to use the selected modem when sending messages to the vehicle.