Sounds like you did some backprobing with all the plugs connected.

For a good tool to use...............go to
http://www.ross-tech.com/
Is the one that is highly recommended!

A good repair manual, Bentley for the USA, is also highly recommended.

I am not familiar how that system works, but it might be a sticking relay or
control module. Probably the ross-tech adapter could help you easily find
the problem. ;-)
There are also clones on ebay and others out there too that are
cheap/cheaper, but the ross-tech adapter holds excellent resale value.

JMHO
--
later,
(One out of many daves)

"Jacek" > wrote in message
...
On Jun 20, 12:27 am, "dave AKA vwdoc1"
> wrote:
> So did you use a vag-com CAN tool to determine that the position switch on
> the transmission is working properly?
>
> "Jacek" > wrote in message
>
> ...
> On Jun 15, 7:34 am, "dave AKA vwdoc1" >
> wrote:
>
>
>
>
>
> > I second that tool!
>
> > It might be a position switch on the transmission, but what does the
> > dash
> > indicator tell you? Does it always read 'R'?
> > Might be a relay too!
> > Not sure what the tip trans has.
> > Have a repair manual?
>
> > "TonyJ" <"tonyjnospam at nospam visi.com"> wrote in
> > ...
>
> >http://www.ross-tech.com/
>
> > > Jacek wrote:
> > >> Hello,
>
> > >> I am trying to solve a very difficult problem which most likely
> > >> involves a foulty electronic module. The back-up lights are
> > >> constantly on and passenger side mirror is tilted down as if the car
> > >> was in reverse, regardless of the gear shift position. The car has a
> > >> tiptronic transmision, by the way. My frastration is high, the car is
> > >> disassembled to a large extend. Most of the electronic equipment and
> > >> harnesses are exposed. I'm running out of options and I would like to
> > >> obtain a diagnostic tool which would let me quiry the electronic
> > >> modules, which are interconnected by CAM bus.
>
> > >> Can anyone help?
>
> > >> Thx,
> > >> Jack- Hide quoted text -
>
> > - Show quoted text -
>
> Thnk you for the advise guys. The problem is far more involved that
> this. A simple back-up light switch applies only to manual
> transmissions. This one has a "transmission range switch" which does
> a lot more. The switch is good. The signal coming out of the
> transmission is good. I believe there is a problem with the
> communicaiton between various modules. Something, somwhere is telling
> the "electrical power control module" to turn the back-up lights and
> tilt the passenger mirror. Something other than the normal signal
> coming from the transmission itself. Short of having various modules
> available and trying to troubleshoot them one by one, I'm stuck. I'm
> afraid a dealer will spend way too much time on it. I don't know how
> well and how quickly they can diagnose the problem.- Hide quoted text -
>
> - Show quoted text -

No, I don't have any diagnostic tools. I don't know what to get,
there are so many of them out there. I did measure the voltage on the
"reverse light" signal coming from the transmission switch and it
reads "0 VDC" on all poositions except "10 VDC" on "R", which
obviously is correct.