I have some observations and questions based on my experience attempting to diagnose and repair my problems. My original problem was actually two problems. The first problem was that the window on the passenger side would not drop when I opened the door from the inside or the outside. The second problem is that the alarm beeps twice about 20 seconds after I lock the car and the red light on the dashboard would illuminate at random times. I noticed the two problems at about the same time and I thought they were caused by the same fault. Now I think that the timing was a coincidence and that I have two separate faults. I base this conclusion on the fact that replacing the door handle microswitch solved the problem with the window drop.
I originally thought that the passenger door lock mechanism was causing the problem with the alarm. I jumped to this conclusion because I pressed against the wiring for the door module when I replaced the door-handle microswitch and it caused the window to drop and the alarm to beep.
Now I am not certain. I scanned the alarm system with my Durametric and the system does not show any fault codes.
Undeterred, I decided to replace the door latch assembly with a VW part. (See post #25.) This did not work at all. I think the electronic components in the VW part are different from those in the Porsche part even though the mechanical part is almost identical. (I note that Pelican sells an URO assembly that does not work on cars with the alarm system, and that may be the issue since my car has the alarm system.
https://www.pelicanparts.com/More_Info/8N1837016C.htm?pn=8N1-837-016-C-M253&bt=Y&fs=0&SVSVSI=1044
I did disassemble my lock module and checked for loose solder joints. Although the solder seemed in good condition, I resoldered the connections. I also replaced the microswitch on my original door latch with the microswitch from the VW part. After reinstalling the latch, everything works, but I'm still experiencing the double beep about 20 seconds after locking the door.
I am now expanding my search for the problem. Possibilities include the sensors on:
1. Both doors
2. Both trunks
3. The fuel filler door
4. The center console lid
5. The top latch
I suspect the problem could also be caused by the switch on the dash or the immobilizer itself.
If anyone has suggestions for further trouble shooting, please feel free to post them.
Thanks,