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898 Posts
Discussion Starter · #1 ·
just posting some text from my tech article. Hopefully, this info will be of use to those who are interested in doing the Nav+ updgrade.
(feel free to add any comments in a reply post. Thanks!)

Install Assumptions:
• Installing a D-Navi Navigation Plus with generation “D†electronics: Audi part#: 4B0-035-192 (Revision F through H)

• 1999.5 – 2001 A6/S6/allroad (C5 chassis): The following information corresponds to the wiring information needed to rewire your A6 to support the installation of an OEM Navigation Plus (aka “Nav+â€). Please note, halfway through the model year (MY) during 1999, Audi refreshed some of the interior and exterior appointments of the A6. A few of those updates include: Concert I tape deck head unit (single DIN size) updated to support the Symphony I tape/CD head unit (double DIN). Also, Audi replaced the instrument cluster to support further items; a digital clock and the support of the CAN-bus communications protocol (CAN-bus explained previously in article).

• 1998-1999 A6 (C5 chassis): If you happen to own a 1998 or 1999 A6, and you want to install a Nav+, you would need to replace the center console area (aka “radio†cage) support a double DIN head unit (i.e. the Nav+). The Audi part# is: 4B0-858-005L; see Also, if you want to install the TMC/CAN gateway device (TMC/CAN gateway explained later in article) in order to communicate the navigation, radio and CD information to the instrument cluster, you will need to replace your analog-based instrument cluster (the version with the analog clock). For most, the cost of the instrument cluster will probably make this option cost prohibitive. Your mileage will vary.

• Multi-function steering wheel (radio controls) might not work with your Nav+: It is widely known that Audi began introducing the CAN-bus into their vehicles during model years 2000 and 2001. Because of this, Audi’s steering wheel CD/Radio controls could have been connected into the radio head unit in one of two ways: as a node/device on the CAN-bus network, or using the REM (“Remoteâ€) lines. Per Dan Gold: The multi-function wheel (MFW) is confusing. The answer is there are two methods used by Audi. In the first method the multi-function wheel controller connects to the REM connection (pin 11) on the 20 pin connector. Cars that used the clock/enable/data lines tended to use this method, but it's not directly related to the communication method to the cluster. The second method is via the CAN-bus. For cars (2002+) that have CAN-based controllers, it won't work without a TMC/CAN Gateway, which you have. While there are different CAN-buses in the car (at different speeds, etc.), the MFW and the Nav+ should be on the same bus, excepting of course that the NAV has to go through the TMC/CAN gateway to do the translation. The actual wheel controllers are confusing to figure out. I "think" the D revision of Nav+ (i.e. 4BO-035-192D, or C-Navi) uses the REM line and the F revision (or newer) uses the CAN-bus, but don't quote me on that. If you learn that your MFW cannot control your Nav+ head unit, then you can always consider swapping out your current steering wheel for a three-spoke sport version. Search on for others who have performed this modification. (Also, worth noting, the newer MFW usually have some VAG settings that you can change. Basically you can set it for pure radio mode, where all 6 buttons do radio things, or mixed mode where some buttons control phone functions. If your lower two buttons on your multi-function wheel are R/T and a phone symbol, it's probably in mixed mode, but you can re-program it. This is all for the CAN based controller. I don't "think" you can re-program the REM based controller.

Multi-function Steering Wheel (MFSW) - Part II:
To keep these controls, a new (CAN-enabled) steering wheel control module will need to be installed and some rewiring will need to be done. If you have a tiptronic wheel, that will not be affected as the tip controls do not interact with the CANbus in any way. Special thanks to Lee Hicks for figuring this out. See this thread for details, part#'s etc:

=D> Update!! See v1.6 (or newer) of Lee's pdf document. He has confirmed that the newer control module will enable MFSW controls for a pre-2002 A6 (and other models). Download his .pdf for wiring details and parts etc:

Your installation will follow suit with this installation done by Dan Gold:

Some other considerations for pre-2002 owners:
• CD player: Nav+ does not have a CD player, it only plays navigation CDs. You need to install an OEM CD changer if you want that capability controlled by the Nav+ head unit. For 2003/2004 owners, you will need to add the CD changer cable to the trunk area as your car was not prewired for it. Please read ahead for the section that covers OEM and non-OEM input devices.

• AM Reception: Depending on your region of the country, Nav+ AM reception might be an issue. See link below for more details.

• Factory Warranty: This is an OEM part, so it won't impact your existing factory warranty. If your car is still under factory warranty, the dealer probably won't replace it if it breaks/malfunctions as this was not part of the original equipment when the car was delivered to you.

• OEM Analog Cellular Phone: This is the factory cellular phone (handset) that was mounted in the armrest and had the junction box (or “brainâ€) mounted in the drivers’ side of the trunk, near the CD Changer. It is unknown whether or not this phone would continue to operate after a Nav+ installation. In theory, it should. Because the only wires behind the Nav+ that would be affected are the mute wire and the two wires for the telephone speaker input. You will also need to use a VAG-COM device to properly configure the speaker arrangement for the Nav+.

See this site for more details:

For the sake of this installation, I divided my installation into two phases for the average “do-it-yourselfer†(FYI – My Nav+ and TMC/CAN installation was done in a 2001 A6 Avant). I felt that the project was too time consuming to try and tackle all at once. By tackling this install in two phases, it kept me from having my entire dashboard apart for entire weekend. I would imagine that the average “do-it-yourselfer†could complete this installation in 10-12 hours (or two 5-6 hour chunks of time for each phase). Not including any potential troubleshooting or VAG-COM reconfiguration work.

· Registered
898 Posts
Discussion Starter · #2 ·
RE: the MF Steering wheel:

Another thought is that the remote wire (REM - pin# 11 in the 20 pin connector) is for the steering wheel radio controls. Normally, it is a white/yellow wire. If you have a 1999.5-2001 A6 2.8/2.7T/4.2 etc with steering wheel radio/CD controls or (MFW), then there is a strong chance that this wire is the same on your Symphony I and your Nav+. Therefore, the MFW should work the same (probably without having to recode anything via a VAG-COM). See this link for details on the B5 A4:


· Registered
898 Posts
Discussion Starter · #4 ·
never done it....and have yet to see it done before (only tip mod). It will take more than a REM wire to do it. I would post your question on also consult the Bentley manual for schematics. Here's what you'll need for parts:

- new four-spoke (MF on 3 spoke not available) steering wheel (maybe?)
- New airbag with MF controls
- New self-cancelling ring ($300 from dealer)
- New control module for MF controls (I've never seen one consult the bent. manual for details)

This could probably cost you $1000+, depending on whether your parts are new/used.

This is the best advice that I can give you.

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898 Posts
Discussion Starter · #6 ·
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 you’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 won’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 driver’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 (“<†and “>â€) instead of the telephone controls. To install, remove the
driver’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 driver’s knee panel. Two you just uncovered up top, one behind the
fuse panel cover, and two on the bottom. You’ll need an 8mm socket to get these out. You also
need to pop out the driver’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.

Open Issue:
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

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