Factory Alarm System

[dacostad]

How good is the factory alarm / imobiliser, compared to aftermarkert ones? (I have a just picked up my new 2001 Boxster S)

David

[Tool Pants]

The only way I know to steal a Boxster due to the imobiliser is if you have the key or tow it away. I have asked 2 Porsche mechanics if there is any way around this and they said no. You do not need an aftermarket alarm.

What a US Boxster does not come with is a tilt sensor. UK cars have this because it is required by insurance companies. Porsche sells a retrofit kit.

[0586slb]

There was one little attention to detail that Porsche made that makes its factory alarm stand out from all the rest: having to get the key into the ignition within 10 seconds of opening the door with the key.

With the RFID and crypto technology thats in use now, the transmitted code from the keyfob is fairly secure. But a lot of manufacturers have the factory alarm wired to the door lock, that is, you deactivate the alarm just by unlocking with a key. Well the thieves discovered that if you force the lock, the switch operates just the same - but Porsche added the feature that you have to get the key verified by the Immobiliser to prevent the alarm sounding.

The front end of Immobiliser technology is again very strong. However, its the 'undocumented features' of systems like this that allow them to be breached. For example, the Immobiliser modules of some manufacturers have a very strong encryption technique, code hopping, seed response etc. but the module sends its 'Yes - OK to start' to the ECM in the same way every time. Its then not difficult to build a module that just says 'Yes - OK to start' and bypass the Immo.

An Aftermarket alarm/immo will just cut the ignition feed, starter, fuel pump and maybe some other circuits, literally at the point where the dozy installer can see where they go (i.e. right next to the starter switch) and stick the control box under the dash with duck tape...

In summary I'd say keep the system factory standard, the Porsche system is quite robust but if they want your car, they'll just take it unfortunately! On the back of a low-loader or towed away.

[dacostad]

Thanks for the information.

[djantlive]

The stock alarm has an IR motion sensor which I find to be quite effective compared to shock sensors that go off all the time.

I don't think you'll do better to prevent theft. You can always add the club and use car cover for additional deterrence.