Central locking problem. Can anyone help please?

[SteveAndrews]

My 1998 996 C2 tiptronic has developed a fault with the central locking and any advise would be appreciated.

I have owned the car for over two years but never used the locking button on the dashboard until last week. Immediately afterwards the car would not lock correctly pressing the key remote, or rather it did but then unlocked itself again with a double beep on the alarm horn. The car can now only be locked by using the key in the lock. When unlocking, pressing the key remote seems to deactivate the alarm but does not open the lock and I have to use the key in the lock but if I don’t press the remote first the alarm goes off.

I have tried various combinations of locking with the dashboard button and opening the door, locking from the dashboard and using the remote to open from the inside but nothing seems to get it working properly again.
When locking from the dashboard the light on the switch comes on and it goes off when it is pressed to unlock. When locking by key, the dashboard switch flashes for a few seconds before going out.
Prior to using the dashboard button the remote and locking/alarm worked perfectly.

It has been suggested that a door locking microswitch may have failed but as it was only by using the dashboard button that the problem arose I am reluctant to accept that as the explanation as I understand I have to buy the whole lock assembly.

Has anyone any thoughts on how I can fix the problem please?

 

[Richard_Hamilton]

I would put my money on a fault in the door lock. It might be a microswitch if it locks and immediately unlocks when using the remote. If it doesn't lock on the remote, it might be the lock motor.

The only real way of knowing is to plug in a Porsche tester, which can read the signals from the microswitches, and the lock motor. The double-beep means there is a system fault, and will have stored a fault code in the fault memory.

 

[SteveAndrews]

Thanks Richard, looks like I'll have no alternative than a visit to a garage.

 

[sebrussellsmith]

I had a locking problem similar to this recently but it locked and immediately unlocked from the remote. There was also the double beep.
I had to replace the drivers side lock and all is fine now.

 

[SteveAndrews]

Thanks for the response. All the advise I get is that it is probably the lock but as it only happened when I used the locking button on the dashboard for the first time, then it seemed too much of a coincidence that it happened to break just then. Anyway I'll probably use it as it is, with it beeping at me when I open it, for a little while before taking a trip to a garage.