liquidTT + VAGCOM
#1
11-01-2008, 06:02 PM
liquidTT + VAGCOM
As you may or may not know, you cannot have BOTH the liquid and VAGCOM hooked up at the same time. They cross-talk each other, and neither gets the information they want. I worked on the TT of a friend of mine today to make a tidy liquid install, and ease use of the VAGCOM. What we did was put a switch in the "data" line running to the liquid. We also hardwired the liquid in to the OBD-II loom so it is always powered.
Steps:
1. Chop off OBD-II end of liquidTT cable.
2. Strip ends of the brown, black, yellow and orange wires, leave about 2" of wire past the black shield coating. Cut other wires off of the liquid cable - they are not used.
3. Remove lower dash, and disconnect the OBD-II port from the dash.
4. Tap in to (or cut) the wires on pins 4, 5, 7 and 16 on the OBD-II port (4 and 5 are brown, 7 is grey, and 16 is red with a white stripe). These are the Audi-side wires.
5. Buy a SPST (single pole, single throw) on/off switch (not a momentary kind). It only needs two poles, so that you are either making a connection or not in the two positions. These are both fine:
http://www.radioshack.com/product/in...ductId=2062497
http://www.radioshack.com/product/in...ductId=2062488
6. Connect the brown and black wires from the liquid cables to the brown wires from the OBD-II cable. It doesn't matter which is which, as they are all ground. (connect one brown OBD-II to the brown liquid cable wire, and the other brown OBD-II tot he black liquid cable wire).
7. Connect the yellow wire on the liquid cable to the red/white wire on the OBD-II cable (this one is power - it is "live", so you should also disconnect the battery before you start all this.
8. Connect the orange wire from the liquid to one side of the switch in step 5. Connect the grey wire from the OBD-II to the other side of the switch in step 5.
9. The wiring is now done, but certainly you should test everything out before putting it all back together. With the switch in one position, the data line to the liquidTT will be active. You should NOT use the VAGCOM in this position. If you flip the switch to the other position, the data line to the liquid will be dead and you can plug in and use the VAGCOM. In BOTH positions, the data line to the VAGCOM will be live - only use it when the data line to the liquid is off.
That's it, leaves a totally stealth wiring job for the liquid, and makes using the VAGCOM very easy.
Steps:
1. Chop off OBD-II end of liquidTT cable.
2. Strip ends of the brown, black, yellow and orange wires, leave about 2" of wire past the black shield coating. Cut other wires off of the liquid cable - they are not used.
3. Remove lower dash, and disconnect the OBD-II port from the dash.
4. Tap in to (or cut) the wires on pins 4, 5, 7 and 16 on the OBD-II port (4 and 5 are brown, 7 is grey, and 16 is red with a white stripe). These are the Audi-side wires.
5. Buy a SPST (single pole, single throw) on/off switch (not a momentary kind). It only needs two poles, so that you are either making a connection or not in the two positions. These are both fine:
http://www.radioshack.com/product/in...ductId=2062497
http://www.radioshack.com/product/in...ductId=2062488
6. Connect the brown and black wires from the liquid cables to the brown wires from the OBD-II cable. It doesn't matter which is which, as they are all ground. (connect one brown OBD-II to the brown liquid cable wire, and the other brown OBD-II tot he black liquid cable wire).
7. Connect the yellow wire on the liquid cable to the red/white wire on the OBD-II cable (this one is power - it is "live", so you should also disconnect the battery before you start all this.
8. Connect the orange wire from the liquid to one side of the switch in step 5. Connect the grey wire from the OBD-II to the other side of the switch in step 5.
9. The wiring is now done, but certainly you should test everything out before putting it all back together. With the switch in one position, the data line to the liquidTT will be active. You should NOT use the VAGCOM in this position. If you flip the switch to the other position, the data line to the liquid will be dead and you can plug in and use the VAGCOM. In BOTH positions, the data line to the VAGCOM will be live - only use it when the data line to the liquid is off.
That's it, leaves a totally stealth wiring job for the liquid, and makes using the VAGCOM very easy.
Last edited by MCPaudiTT; 11-01-2008 at 06:09 PM.
#4
11-01-2008, 06:23 PM
liquid would be used "all the time", but use the VAGCOM for specific diagnostics that the liquid can't do, or if you want to log/graph/analyze a bunch of data on a computer at a later time (can't offload data from the liquid and analyze in Excel).
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