Faulty Pneumatic Door Lock System on 4KCSQ

Doug Johnson ur-quattro at msn.com
Tue Aug 9 18:47:36 EDT 2005

Thanks to Keith, Eric and Huw!

You fellows are right, it does appear to be the switch in the driver's door.

For some reason, on my way home from work today I lifted the button on the
passenger door, and all the doors unlocked.  ;-)

Again, thanks to everyone!

~ Doug

-----Original Message-----
From: Huw Powell [mailto:audi at humanspeakers.com] 
Sent: Tuesday, August 09, 2005 4:19 PM
To: Doug Johnson
Cc: LawyerKG at co.laplata.co.us; quattro at audifans.com
Subject: Re: Faulty Pneumatic Door Lock System on 4KCSQ

Here is some handy info:


The switch in the drivers door is a simple mechanical one.

The rpoblem won't be a leak, since it works in one direction.


That switch is bad
The "unlock" wire is bad (could be broken in door jamb...) The bi-level pump
does not work in "pressure" mode, only "vacuum".

> Is this an electric switch; i.e., a solenoid?

> IIRC there's only one vac line to each door solenoid.  I think your 
> switch in the driver's door is bad, thus it's not recognizing that 
> you've unlocked the drivers' door and not telling the vac pump to engage.

> Although all of the other doors on my '86 4KCSQ lock when I lock the 
> driver's door with the key or by pressing the lock button on the door, 
> none of the other doors un-lock when I use the key to lock the 
> driver's door or when I lift the lock button to un-lock the driver's door.

Huw Powell



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