Re: 2003 Factory Alarm Issue
Ok, there is a door cylinder lock switch which is mounted on the inner side of the outside door handle. You can measure the resistance of this switch when you disconnect it. It should be 473 Ohm in lock position and 1994 KOhm in unlock position (both plus or minus 10%). When not in limits, you have to change the switch. When the switch is ok, there is probably a loose or broken wire. The switch is connected to the Driver Door Module, from where the signal is send to the Body Control Module. A weak point of the wiring is where it passes from the door to the body. (inside the rubber sleeve) This one is easy to remove and maybe a good point to start with.
To get access to the switch, you have to remove the inner door panel.