So, as the title states I'm having problems with the central locking system on my girlfriend's 98 Audi A4 Quattro. I know the pump runs fine as all the doors will unlock and lock, plus I have a spare that I pulled from one at a junkyard. I only got one key with the car, the buttons on the remote don't work. I'm just assuming it needs to be programmed. However that is the least of my worries right now. Now that you have a little background on the car, here's whats wrong.

When I unlock the doors from either the driver's side or passenger side the instrument cluster and heater controls turn on, almost as if the key were in the on position in the ignition. Once the instrument cluster and dash comes on the only way to turn it all off is to disconnect the central locking motor in the trunk. Specifically the black plug that is raised above the rest.

When I unlock the doors from the truck this does not occur, the door locks will function as normal.

If I have the central locking motor connected in the trunk while the car is running and try to shut the car off, the car will stay running even if I pull the key out of the ignition. Again if I disconnect the central locking motor in the trunk, the car will shut off.


I don't have a VAG cable yet, however I will be investing in one soon. Locking the doors manually is getting very old and I want to fix this problem.

 

I read on another thread about this issue and some gentlemen claims the central locking device or controller is pretty expensive to replace.

Lets hope you don't have to replace yours but if you do go to a junk yard and start tearing audi's apart.

 

I got one on Ebay, $125. Than, I got another from my local auto wrecker where you can take stuff off yourself, Crazy Ray's in Baltimore, $25.

I believe a new one is about $950 aftermarket.

I had other strange symptoms like yours but different. Finally, with the used $25 version all is well.

There are good sources of key fob resetting techniques, search the forum here. I suspect the key in the ignition is just to turn it to accessory and does not have to be an electronic key, but I am not sure.

Here is my forum post on my problems -

https://www.audiforums.com/forum/b5-...others-197367/