Key 4 ???
 

Could someone tell what this key does???

Well sorry I'll post a picture when I get home apparently you can't post pictures from your phone

I give, what key?

Probably an alarm system.

factory alarm...wish mine worked...

Alarm.......don't screw with it. Nothing but problems.

thanks...
 

THANKS!!!!!! did it have a special key.... my door key won't fit....ooops

The alarm key is completely different than the other keys. It's just a slender, plain metal key. It doesn't work anything else in the car and none of the other keys work the alarm. In the old days, Porsche didn't sell those keys separately, you had to buy a new switch. I don't know if that has changed, you might ask a dealer.

JR

+1 OEM factory alarm
http://img.photobucket.com/albums/v5...ps0df344d1.jpg

The key switch in the door has a ~4.6K resistor in the circuit when unarmed. when the switch is turned to armed the resistance is dropped to ~2.4K and arms the system. In essence you are putting two 4.6K resistors in parallel to arm the system.

I never did have the alarm key to my car and when I added a keyless entry system I used one of the outputs to add the second 4.6K resistor in parallel to the switch at the alarm module. When I lock the doors with the remote the alarm is armed automatically.