Wiring the Instrument Cluster to the TMC
If you would like the Nav Plus unit to communicate with the center console, wiring must be added from the TMC to the center console. A TMC is required for this communication.
First, remove the instrument cluster. Adjust the steering wheel as far out and and far down as it will go. Push in both covers in picture below and remove from instrument cluster.
Push in covers to remove them, exposing hex screws.
Remove the two 4 mm hex screws. Remove the instrument cluster towards front. Cut the cable ties on the back side of the instrument cluster. Release the retaining tabs on harness connectors (3) and disconnect connector. These connectors are very similar to the Nav Plus 26 pin connector. The release must clear the tab, then rotate it and the connector will pull out of the instrument cluster.
Instrument cluster removed. There are three connectors to the instrument cluster.
You will be working with the green connector.
The TMC wires must be attached into the Infotainment CAN wires. This is a media system CAN that has the Nav Plus/Radio, phone and TV tuner. These wires can be found on T32a/21 and T32a/22 which is the green 32 connector. Below is a schematic of the CAN wires that are used.
NOTE: I have verified the 00-02 schematics, I do not have the 03 schematic. So check to make sure the color wires are correct before tapping into them.
Wiring diagram for Infotainment CAN wires at cluster. Click image for full size image.
Cut the tie wrap at the 32 pin connector and cut back the insulation tape.
Disassemble the connector by pulling the purple end cap down and off the green connector. Then working from the outer end, just push the insides of the connector out of the green casing. Find pins 21 and 22 (by looking at the pin numbers on the green casing). You will see that they are orange/brown and orange/violet.
There are many ways to make a connection including using insulation displacement connectors, but I don't like these type connectors because they are bulky and these wires were twisted and wouldn't allow for insulation displacement connectors. I ended up installing new wires into the terminals and soldering everything up.
Disassemble the connector and you'll easily find pins 21 and 22.
The two wires were twisted in the bundle and did not
allow for room for insulation displacement connectors.
If you want to do it the way I did it, use two new wires in the terminals. You'll need one Audi part number 000 979 003A, which is actually two connectors. To remove the existing wire, look at the new connector to see how it works. Using a small diameter tool, such as a dentist pick, place it in the connector right near where the instrument cluster pin goes in it, at the angle clip on the connector. Push the angle portion of the connector so it will release and tug on the wire. It should come out easily. If you have trouble, just study the new wire/connector and you'll figure it out.
Insert the two new wires. Attach them as follows:
Connect: New pin 21 wire, orange/brown wire and CAN low wire attached to TMC 12 pin connector, pin 2
Connect: New pin 22 wire, orange/violet wire and CAN high wire attached to TMC 12 pin connector, pin 3
I soldered the connections up. Reassemble connector and install a new tie wrap. After this was completed, heat shrink the connection with some heat shrink tubing, tape it up and tape the harness back up leaving the two wires that go to the TMC out of the loom.
Connections made up and soldered.
Soldered connections heat shrunk and taped up.
Insert the three electrical connectors back into the instrument cluster.
Before installation of the instrument cluster back in the dash, I would check that the car starts and the dash has all lights lit and looking normal. If for some reason your car dash doesn't light up correctly, you need to remove the connectors of the back of the instrument panel and reinstall them until it is correct. If you don't, your car might not start, or stay running once it does. Reinstall the instrument cluster into the dash.