Just an update on Multifunction Steering wheel (radio controls) if your car had a Symphony I head unit and you upgraded to a Nav+ (RNS-D). Special thanks to Lee H for doing all of the research and leg work on this one. I should also point out that this should only be considered if you have a D-Navi as the C-Navi relyies on the CLK and DATA wires to communicate with the instrument cluster.
Just installed a Nav+ in my C5 A6/allroad/S6 (1999.5-2001), B5 A4/S4/RS4 (1999.5-2002) and D2 A8 (1999.5-2001)
You can rewire your existing MF wheel to work on the CAN bus by replacing your current MF steering wheel control module. The part# for the 2002+ (CAN enbable module) is: 4B0 907 487 F ($185 USD). You will also need to do some additional rewiring from the new control module to tap into CAN H and CAN L.
See also Lee's PDF (page 3-4):
What I am about to describe is the way I chose to get the CANbus network to my radio. It is very
important to proceed this way if you have steering wheel audio controls and want to keep them
working. This will incur significant additional costs because you have to purchase a new steering
wheel control unit that talks to the CANbus network. Even if youâ€™re not ready to buy this part, I still
suggest that you proceed with my directions so your wiring will be prepared for that decision in the
Remove the CLK wire from Pin 8 of Connector I and reinstall into Pin 7 (CAN H) of Connector I.
Remove the DATA wire from Pin 9 of Connector I and reinstall into Pin 12 (CAN L) of Connector I.
The next bit of rewiring to be done is behind your instrument cluster. This seems daunting but is
actually pretty easy. Again, you may want to cover the top of your steering wheel column cover to
prevent any accidental scratching. Remove the center trim piece between the steering wheel column
and instrument cluster by pulling straight out. Remove the two Phillips screws holding the bottom of
the instrument cluster in. Mine were VERY hard to remove but finally got them to budge by first
tightening the screw (just to break it loose) then turning the other way to remove. When you have the
cluster loose, remove by pulling the left side out first, unplugging the blue connector on the left, then
the grey connector in the middle, then the green connector on the right end. Each of these plugs has a
small purple clamp that holds it in place. You have to simply lift this purple clamp up and the plug
will remove itself from the cluster.
The grey connector must be dismantled to change the wiring. This connector is called T32c. You have
to slide a little purple clamp off the bottom, remove the cable tie from the bottom and then slide the
grey cover off the top of the connector. Once inside the re-wiring is simple.
Remove the CLK wire from Pin 12 of T32c and reinstall into Pin 5 (CAN H) of T32c.
Remove the DATA wire from Pin 13 of T32c and reinstall into Pin 6 (CAN L) of T32c.
If your wires wonâ€™t reach up to their new pin locations you may have to install a new wire terminal
and splice them into the wires somewhere outside the connector. Reinstall the grey cover, purple
bottom clip and cable tie onto the connector. Reinstall all connectors onto the instrument cluster,
making sure the purple clamps lock into place before you reinstall your cluster. Reinstall your cluster.
What you have just done is change the CLK and DATA wires that run from the cluster to the radio to
CAN H and CAN L. What this also accomplishes is reassigning the correct pins on your steering
wheel control unit to also be on the CAN network for proper operation. This is when you decide
whether or not to install your new steering wheel control unit. This unit is located in the relay panel
behind the driverâ€™s side knee panel. It is a double width control unit that takes up relay slots 7 and 8
which is the middle row, far left, kind of tucked up behind the back of the fuse panel. Your current
steering wheel control unit will not work on the CANbus network. If you choose to purchase and
install it, there is no more rewiring to be done. You just have to unplug your old unit and plug in your
new one. The good news is, with the new unit, you can VAG code it so the bottom buttons are for the
preset and disc change functions (â€œ<â€ and â€œ>â€) instead of the telephone controls. To install, remove the
driverâ€™s side knee panel by continuing to the next paragraph. To skip this control unit install for now
then skip the next paragraph.
Changing your multifunction steering wheel control unit
Remove your fuse panel cover on the left side of the dash by gently prying the cover off. There
are 5 bolts that hold on the driverâ€™s knee panel. Two you just uncovered up top, one behind the
fuse panel cover, and two on the bottom. Youâ€™ll need an 8mm socket to get these out. You also
need to pop out the driverâ€™s footwell light and OBD II connector before pulling this piece
completely out of the car. Look up in the footwell behind the fusebox and you will see a
control unit, probably with the number 608 on the top. It will be on the middle row, far left
side. Pull this unit out and reinstall your new unit in its place. There is no further rewiring to
be done, all the pins have been properly reassigned to the CANbus network based on the
wiring you have already performed in this article. Reinstall your knee panel with the 5 bolts
and replace your fuse panel cover by snapping into place. The next paragraph returns us to the
Symphony II install.
Reinstall your trim piece above the steering column. The instrument cluster wiring is now complete
and your car is ready to roll on CANbus.
It is unclear whether or not you need to have a digital clock in your instrument cluster to do this. The inst. cluster with digital clock is necessary if you want radio/CD/Nav info in the DIS.
I have yet the hear/see someone do this yet but, I imagine that