Mercedes Benz repair: Car wont start, car wont start, auto help

Question
I have a 1995 s420 mercedes benz when unlocking the doors manually with the key my car wont start.

Answer
Ok at what door , Trunk or at any? The manual function turns a cylinder that is suppose to send a message to the alarm system to deactivate. Does it work with the Infared signal? Do all doors unlock?
I need to know. so that I may guide you in the correct path.
Let Me Know
Ralph
Miami Auto Help Inc