John Alden
Battery died. They can go overnight once the cold weather moves in.
The Devil
The owner's manual is your friend, which wants very bad;y to help you with this. Oh, if you would only get it and read it a little.
Rinkydink
When originally purchased the security code should have been issued and noted in the operational instruction book. Everything in the car worked except the radio. Recently I had a similar problem after I charged the battery in my 1999 MB. I contacted the dealer and identified the last 4 digits of the VIN #. I inserted it on the radio window when prompted and the problem was fixed. Good luck.
Trump 2020
Replace the battery if it's more than 4 years old.
?
The battery is dead.