Alarm sounding randomly. Durametric software not reporting any problems. Suggestions?
 

2000 Boxster S 6 speed.

Two days ago the alarm started sounding randomly when the car was locked and unattended. I fired up my Durametric software. It shows two alarm modules. There was nothing obvious under fault codes for either, but there were years of random glitches. I cleared all the codes for both modules yesterday.

Today the alarm sounded at lunchtime. I just plugged in the laptop. No fault codes showing for either modules. Is this where a log of alarm triggers would show? I cannot find anything else related to the alarms. Supposedly, the modules store the reason for the last 10 triggers and that can narrow down the search for the fault. I cannot see this information. That may be user error.

Any suggestions for other fault finding? I checked the doors and storage spaces were secured and not flapping in the breeze.

I just tried locking the car with two quick key fob presses. I believe that disables the interior motion detector, apparently this is a common module to fault in these cars. I can give it a few days and see if there are more alarms, then go back to single press locking it and see if it happens some more (and annoy all my neighbors)

One thing I tried that was suggested, but is not in the manual, was a quick triple press of the key fob. This is supposed to lock the car but not turn on the alarm. It does not work on my 986. Instead it unlocks the car again! I suspect Porsche might have added this option to later cars after too many angry owner complaints that they had an alarm fault and so could not lock their cars until it was fixed unless they wanted to wake all the neighborhood at night. Slight security issues.


Suggestions welcome

Thanks