ZV, kaput? (F

[cab - dk]

Hi
I'm the happy owner of an Audi Cabrio 2,3 from 1992.

I have just finished putting it together after a new layer of paint. Now i have some trouble with my "powerlocks" (Zentralverriegelung). It is unfortunately a periodic faulty.
Sometimes, when i'm locking the car, it will only lock the trunk, and not the two front doors.

Why? Is it the "steuergerät", is it the pump or is it an electrical problem?

I realy hope you can help me. I'm desperat! You can write in german. I understand, i'm just not good at speaking it!

Viele grüsse
Rasmus aus Dänemark

[pray]

Hi Rasmus,

I guess both languages are possible over here, if we don't have to answer Danish

To your problem. How far did you dismount your vehicle before the painting act? Maybe you have a cable connection problem somewhere. Watch the trunk area in particular.

Another eventuality is a leaky vakuum system. check all connections as well at the pump as the lock. I f your pump works more than 5 sec. it's a good hint, that something is leak.

If this fault happens only now and again it sounds like a loose connection somewhere.

best regards

Klaus

[Lord of the Rings]

Dear Rasmus,

my Danish is a little too rusty, so I will answer in English.

A couple of possibilities come to my mind:

1. You mentioned that your car got a paint job done, could it be possible that it was exposed to high temperature for a longer period of time? I believe Audi allows for max 80° for a period of 90 minutes, otherwise the car needs to be stripped completely. If that is the case the vacuum pump (Bi-Druckpumpe) - which includes the electronic control of the power locks, as well - might got damaged.

2. Vacuum leak in the vacuum hose system.
The Vacuum pump - provided the system is in good working condition - shall lock all power locks within 2 seconds. If the pump operates for more than 5 seconds, then there is a leak in the system. If there is a leak, the pump shall operate for a maximum period of 30 seconds. Than the control unit shall stop the pump.

If the pumps operates for more than 5 seconds, you know there is a leak:
Locate the vacuum pump behind the rear cover on the passenger side and inspect the hose to the first T-divider. Remove one hose after another from the T-divider and close the opening at the T-divider with a finger and operate the vacuum pump in order to identify the leak. Continue with the remaining hoses and T-Dividers.

Unfortunately the vacuum pump cannot be repaired - some people in the board mentioned that they did anyways - and is pretty expensive ($380 CDN).

3. If the pump is working properly and there is no leak in the system, you should check all electrical connectors. All power locks have an electrical connection to the Bi-Druck-Pumpe. Therefore you need to uninstall the door panels, the trunk lid cover and the right trunk cover to get access to the trunk lock and the fuel lid lock.
Check with an Ohm-meter the connections and replace broken cables.

Please don't hesitate to post your findings and any additional question.

Good luck
Lord

[pray]

In addition to Lord's perfect explanation let me mention that you can get a used vacuum pump for approx. € 130 - € 150 at ebay's. (used one) in case of an irreparable damage.

[cab - dk]

Thank you for your fast reply!

I think i will start checking the trunk for loose conections. The weird thing is, that it is no problem to unlock the doors. I forgot to write that (sorry). The "ZV" is working perfect, unlocking. Thats why i don't think it is the pump or a leak in the vacuum system, or is it possible anyway?

I realy appreciate your help

[Lord of the Rings]

Despite the fact that you can unlock the car without trouble, there is still the possibility of a leak:

The car unlocks with a pressure peak and locks with vacuum.

Unfortunately, the pump produces a higher pressure peak than vacuum, which might allow for proper unlocking but you will experience problems when locking.

Just follow the instructions above and determine by the working time of the pump whether there is a leak, and continue respectively.

Lord

[Uwes]

Off topic:

Realy great ! Brush up your english with audicabriolet.de

Wenn das kein Board mit Mehrfachnutzen ist..

Cheers !

Uwe

[cab - dk]

Thank you very much! I will look at it the first comming weekend. I will let you know, when I find the fault... Well, I HOPE I will find it