Porsche Enthusiasts Club Forum

Remarkably they still have original modules and fobs for sale, as I made an enquiry with them just a couple of weeks ago when I was fixing my old H&P system. Note the H&P boxes were not an alarm as such, they just interfaced with factory unit to provide facilities like remote operation and cabin sensors (the ultrasonic box you found), since the factory alarm box had provision for extra trigger signals on top of those provided as standard from doors/hatch/bonnet/radio,

Exactly same logic here.

Mine seems to be a multi point immobilizer as I did trace with black wires going to various areas under the dash. The main box attached to the floor under passenger seat. Saw this when I stripped the car for paint, & at the time "cleaned up" various wiring as well as removed factory alarm. Still beeps when disarmed etc & have two electronic Porsche keys which plug into a socket, which I have fitted close to the ignition key.

Carrying the two to test when I use the car as one seems to need a wiggle to work sometimes. So might need to order replacements in the future.

Right where I found mine

Only found it as I couldn't get the seat to go back and forwards on the adjustment and found that the box was jammed between the carpet and the seat. It had been disturbed when I'd had the bodywork and paint done and just needed to be tucked back under the carpet to stop it catching on the seat.