Audi 80. Alarm problems

[Juuso]

Hello.

I have an Audi 80 from 1994. I believe the model is b4 8C2. Its a 2.0l gasoline automatic. I have been trying to figure out the problem in it for a while now. 

 

Firstly it only used to unlock all the doors from the trunk and if you used other doors it would set off the alarm, until one day when the boot also did the same. Ever since it has no working central locking and does not shut off the alarm and immobilizer. The pump for the central locking has been changed and fully cut wires from the boot have been fixed. I have tried to find the immobilizer but have not yet found it. Also i have followed the wires for the pump but they seem to be fine. Neither pump seems to be running but the wiring does have voltage coming in.

 

I have checked all the fuzes in the fuze box and tested varieties of fuses according to different diagrams.

 

Thank you.

[coupe4]

hi juuso,this is a common problem with these models,i got an autoelectrician to disconnect my immobiliser and the i disconnected the central locking pump myself,no problems since but it means all doors need to be opened and locked manually,i hope this helps.Greg

[cliffcoggin]

Is this the vacuum operated locking system? I recall a similar forum question a year or two ago to which there was no resolution sadly.

[Juuso]

Yes. I have gone through a whole lot of forums and post that have not ever resolved the problem. But im hopeful someone happens to find this and have a new fix. Also i have figured that ill have to check if the wires from the boot are broken in multiple places possibly because first we found some of them had been cut due to the constant wear. But they could be broken from multiple places. Since if i measured right the vacuum electric wires are getting power when they should not but the vaccuum pump still is not running. And if worst comes to worst im going to try and bypass the alarm and immo.

[cliffcoggin]

I wish you luck.

[Juuso]

Well the issue might have been found in the boot loom connector. Unfortunately i do not have time to fix it now but i will see in the comig days.

 

 

Edited 2 hours ago by Juuso

[Juuso]

On 5/20/2025 at 10:37 AM, coupe4 said:

hi juuso,this is a common problem with these models,i got an autoelectrician to disconnect my immobiliser and the i disconnected the central locking pump myself,no problems since but it means all doors need to be opened and locked manually,i hope this helps.Greg

I believe in my case the alarm/immo is built in the pump itself. I have not found any box for the immobilizer in the car.