94 E320 factory anti-theft system?

[LETSROLL]

My key will not open all the door locks. It only opens driver/passenger door not the rear doors and I had to have the car towed because the key would not engage the starter to engine. I have had the problem in the past from opening passenger door and then driver getting in and the car would not start. i would have to close and lock the car then unlock the car to stop the ignition cut-off. Is there na way of disengaging the door lock auto shut down feature? If I have a problem with the doors opening by key, I will just open one at a time, but having the ignition not operate because of electrical security system, I would just as soon disengage so the car starts. Is there anyone familiar with how to get the key ignition to engage the starter? I turn the key and all lights come on, I hear a buzzer, I turn the key further to the right for the starter ignition and there is no response. What can I do to fix or bypass this security feature? This happened without warning, the doors used to all lock and unlock, the only thing I can think of last was having the Geek Squad at Best Buy install a radio I bought there a couple months back.
Thanks,
Tom