Hose inpection on Multi Function switch for automatic transmissi

[Franco Barber]

On Wed, 20 Nov 2002 13:02:36 -0500, <gkot at adelphia.net> wrote:
> From: <gkot at adelphia.net>
> Subject: Hose inpection on Multi Function switch for automatic transmission
>
> The multifunction switch for my 1994 CS quattro (also know as park neutral =
> safety switch) went bad. It is located on the outside of the transmission c=
> ase.
>
...snip...

The same switch went bad on my 95 A6q automatic.
On the 95's, the switch is behind the left side transmission mount,
and impossible to get to without removing the mount.
Can't tell you if there's a hose attached or not - no way to see it.

The switch on the 95 is a 5-pole switch.
Three of the poles drive the gear indicator on the dash.
One pole drives the neutral safety.
The remaining pole drives the backup lights and energizes the
tilt down passenger side mirror (if so equipped.)

The only clue I had that mine had failed is that the mirror stopped
going down.  I was complaining about this to someone, and he
innocently asked "do your backup lights work?"
I hadn't even though to check them.

If you follow the wiring diagram, you find out that of all
the circuits that this switch drives, only this pole
(the backup light pole) drives a relay.  The other poles drive
electronic modules with high impedance inputs.
So, if the switch starts to fail by having higher resitance when
the contacts are in a closed position, the pole that drives the
reverse lights was the first one to make itself known.

The switch could fail in other ways, but mine chose to fail in
this way.  I didn't feel like taking the transmission mount off
the car by myself, so I let the dealer do it, and it wasn't a
pretty price.  $250 plus a couple hours labor sounds about right.

Franco

--
Franco Barber                   feb at febsun.cmhnet.org
95 A6Q w/Gamma CD mit RDS!      Columbus, Ohio  USA
95 A6Q 5spd