I don't know if you have a chip in your key. My '96 E does not, but I am not sure about the '97 which also uses a blade in the ignition cylinder.

I believe that in the early 210, the problem occurs when the computer does not receive power from the ignition switch or K40 module (both are involved). DAS notices that it can't communicate with the computer and shows non-authorized (DAS attempts to verify that the correct engine computer is installed in the car).