I suspect a door lock switch or wiring connection has gone bad.

Sorry I can't help beyond that.

A piece of alegorical advice... when I had this problem in my 1990 w/ an aftermarket system (Clifford) I took it back to the place that installed it. It came with a lifetime warranty on the installation which I've used taken advantage of numerous times. What goes bad is usually a connection/connector and rarely an electronic component. The warranty also covers the pin switches and other wear items so to this day it continues to work without fail. <img src="/forums/images/graemlins/kewl.gif" alt="" />