Chrysler Repair: 2002 Town & Country wont start, chrysler dealer, chrysler dealership

Question
I have a 2002 Town & Country LXI with a 3.8L engine that will not start. Several months ago when the check engine light came on we took the car to an auto parts store that did a diagnostic check on the car, we were told that we needed to replace the ignition control module or unit. After several calls to the Chrysler dealership I believe the part is not an ignition control but an engine control module. What I would like to know is there an ignition control and an engine control module for my vehicle? If either one of these parts would cause the vehicle not to start? If it is the engine control module, can this part be tested if not in the vehicle? Any help would be appreciated as the Chrysler dealer wants $800 for the engine control module which a little beyond my means and have found a place where I can get the part for about $300. I have a private mechanic and would prefer not to have to tow the vehicle all over the place.

Answer
The computer in question they are Called A PCM Power Train Control Module.All of the ign starting and so on is done through this one computer  there is only one so no separate things that is a module for that. Next  how many miles do u have on your van and if u have it what was the codes they pulled from the PCM to tell them that they needed a computer?
Second thing this 300 computer  is it aftermarket one,junk yard  used  or what?? I have reason behind this asking this once u tell me where u plan on getting this computer from. OH one more thing do u have a gray key for your van?