Ok, I've asked this before, but haven't really gotten any answers, and my googling has been unfruitful as well, so I'm hoping to explain it better this time.

- Both of my key fobs work as expected
- I can use my key to lock the car (99 XJ8 VDP), and when held in the lock position, it will close all the windows and sunroof if needed.
- Problem: The alarm sounds immediately if I unlock the door with the key. The door does unlock, but the alarm begins sounding before I even have a chance to open the door. I can shut off the alarm by turning the key in the ignition.

Any ideas?

 

Unfortunately, the Jag documentation goes out of its way to not give step by steps or sequence of operation documents for the security system, probably due to , well...security!.
I GUESS that your problem might relate to a switch input being in an unexpected state as you open the door. You might want to see if the door lock switch is turning on both the lock and unlock contacts as you turn the key. The best device to test that is a 12 volt test lamp.
Also, does this occur if you lock with the key OR the fob? What if you lock while inside, then open the door? Does the interior light operate as expected during the lock sequence?

 

Sorry for my delay in responding back.
Yes, I think testing the door lock switch is going to be my next step.
It sounds the alarm immediately whether I've locked it with the key or with the fob. And the interior light operates as expected when locking, but I haven't paid attention to what it is doing when unlocking with the key, because I'm rushing to get the key in the ignition to shut off the alarm. I'll check on that.

Thanks!