Well, the fuse removal/reinstall does the trick. It obviously isn't melted. Somehow, the Cell Phone Passport Module looses the connection and ESN (I think that what is called) on-board modem serial number is no longer displayed by vehicle settings menu. Once fuse is r&r'd, the CPPM is reset and everything comes back. I will try it again today and see. Maybe you are right and negative battery lead disconnect is easier, but doesnt it wipe off all the data and vehicle needs to be registered again? I really would like not to go thru registration again. And I drive it every day, so 12V battery shouldn't be the issue (only 1K miles on the car). Also, if cell phone connection is the cause, wouldnt it restore connection once strong signal is established? That is not clearly the case. I've been around areas with 5bars and LTE, but the CPPM modem serial number is still blank, meaning the module is not reset and not talking to the cloud server.