993 Drive Block alarm system

[Npporsche]

I'm having a problem with the Drive Block alarm system on my 993. My alarm fob has stopped working (tried a new battery but that hasn't worked) and I have ordered one from Porsche so it's the correct one. I've followed the process of trying to sync the fob with the car as per the handbook and various youtube videos. But when you set the alarm with the key the door red light double flashes indicating that one of the contacts is not connected. The only contact that I can think of not working might be the stereo due to new stereos being installed over the years.
Couple of questions:
Does anyone know what wire behind the stereo needs to be connected to make the car know that it's connecting to the alarm, then allowing me to sync the fob?
Is it possible to take the Porsche alarm out as I already have a Thatcham Cat 1 alarm installed already?
Finally, anyone expert garages that might be able to help?
Any help much appreciated.

 

[Gwsinc]

The green wire behind the radio won't affect anything if you tape the end off.

The drive block system uses a different system to sync dependant on the year of the car, 94-95 uses a 40 min timed and sequenced switching of the ignition (I surprised myself when this actually worked!) and then the 2nd method for later cars is the one on many YouTube videos etc. I have a link for the first method I can send if yours is an early car?

Your most likely issue, noting the car is doing something when the button is pressed, is one of the micro switches isn't closing. Doors (although if open it shouldn't let you lock), bonnet, frunk, glovebox all have lights associated with them so fairly easy to work out if they work or not. For bonnet and frunk test by clicking the mechanism shut by hand and checking the light goes out, but do remember to re-open the latches before closing either!

If your glovebox is 'loose' this could also be your issue.

Edit: for clarity, drive block is the factory immobiliser system, which interacts with the original Bosch style single-button fob. If yours is a uk delivered car it shouldn't have drive block. Hope this helps.

 

[ToreB]

Most, if not all UK-delivered 993's had the Hamilton and Palmer alarm system installed at the factory or the dealer. I guess all of them came with a USB-like fob that needs to be inserted in a socket.

Porsche Drive Block is the Porsche immobilizer system, and not very often seen in Europe. It was standard in US cars. These cars have the original Porsche key fobs with push buttons. Registering a new key fob to the Drive Block control unit is a exhausting endeavour.
The Drive Block control unit is known to develop faults due to component ageing, but this is possible to repair. The key fobs are also prone to failure due to rough handling and corrosion over the years.

As one should expect, it is not an easy task to remove the Drive Block system. The early 1994 models are a bit easier, but later models have a integration between the Motronic engine control and the immobilizer units. Disabling this needs a new engine control unit memory "chip", as well as several other modifications. A US vendor makes a Immo Block add-on unit that removes the need for pressing the key fob to deactivate the immobilizer. However, the Drive Block unit is still used for remote controlled lock and unlocking of the car.
Cheers,
Tore

 

[Heuer]

Tore

My 993 C2 was delivered in 1997 and comes with the H&P PA2000 Thatcham Category 1 alarm which incorporates the factory fit Category 2 immobiliser. It does not have the dongle, just the two button remote for unlocking the doors and defeating the immobiliser.

The earlier H&P PA1000 system has the dongle I believe as it is the immobiliser rather than the factory fit Cat2 immobiliser. I think the PA2000 was fitted from 1995 onwards.

 

[AndyS]

Interesting thread.....
Mine is a '96, and has the H&P with a single button and the stupid blade - so not sure if this is the PA1000 or the PA2000?

Either way, I understand support for these systems is about zero going forwards, so I was thinking of having it removed and replaced with something a little more modern.
I don't want to hijack this thread looking for guidance on this, so will start a new thread on that subject.

 

[ch3tman]

Mine is a '96, and has the H&P with a single button and the stupid blade - so not sure if this is the PA1000 or the PA2000?

Either way, I understand support for these systems is about zero going forwards,

http://911uk.com/viewtopic.php?t=96931 :thumbs:

so I was thinking of having it removed and replaced with something a little more modern.
I don't want to hijack this thread looking for guidance on this, so will start a new thread on that subject.

http://911uk.com/viewtopic.php?t=129945 :thumbs:

 

[AndyS]

Mine is a '96, and has the H&P with a single button and the stupid blade - so not sure if this is the PA1000 or the PA2000?

Either way, I understand support for these systems is about zero going forwards,

http://911uk.com/viewtopic.php?t=96931 :thumbs:

so I was thinking of having it removed and replaced with something a little more modern.
I don't want to hijack this thread looking for guidance on this, so will start a new thread on that subject.

http://911uk.com/viewtopic.php?t=129945 :thumbs:

Thank you - I should come here more often, then I wouldn't miss stuff like this :thumbs: