Power Door Locks don't unlock 97 deville

I am having trouble with my 97 deville. The doors all lock, but only driver's door will unlock. A dealership (http://www.cadillacforum.com/Power_Doors_Don%27t_unlock_97_deville/m_1119/tm.htm#) checked it out, and they said the actuators are all OK, but the problem is in the module or some computer that controls it. I am not sure what they called it, but they wanted like $600 for it. Does anyone know any information about this, and if it is something I can pull of another model in a scrap yard or something? Thanks -Dan