I mounted the LC1 with tie wraps under the MyECU, and used the diagnostic plug wiring in my harness to bring in the signal, since the diagnostic plug is no longer used.  If you check my link, you will see a red and a blue wire going from the harness connector to the O2 input connector.  You can use either one of those pins to make the internal connection since you are using one O2 sensor.  Based on Carl Allison's V11 schematic, it is probably either pin 9 or pin 10 that you can use internally, and pin 1 or 3 of the diagnostic connector.  Here is the link to my pictures, followed by the link to the V11 schematic.  I do not have a V11, so this is all at your own risk, and my advice is free, so you are getting your money's worth.
https://picasaweb.google.com/106090307548421468637/MotoGuzziProject?authkey=Gv1s
RgCOvxnMyo6oiyfQ

http://www.thisoldtractor.com/guzzi007/schematics/1999_V11_sport.gif

Hope this helps.

Yes, I ended with a cluster of ground wires at the point where the wiring harness ground wire attaches to the ECU case, and I spliced a weather proof fuse holder into the +12V line from the LC-1 going to the fuel pump relay ( the red wires visible in the picture showing my battery compartment).  As I remember from the LC-1 instructions, the grounding was a critical issue, which was why I did it that way.  I ended up having to get a longer screw for the ground connection, because the original screw was too short after adding the stack of ground lugs.  There are three ground wires: a bare shield wire, the power ground, and the sensor ground.  If you add the calibration circuit, it needs a ground wire also.

For some reason, part of the link is on the line below.  You would have to paste the two pieces together, or find where I posted the link earlier in this forum, or maybe Cliff can fix my link.  MyECU does not use the diagnostic function, that is for the Marelli unit, I believe.  I'm glad you have the correct schematic to refer to.  In my Sport 1100i, pin 2 is ground, so I used 1 and 3 for my O2 sensor lines.  The diagnostic plug just shorts the lines together in the M16 unit, and there is a diagnostic light that flashes to give a trouble code.  I don't know what they did in the M15 unit for the V11. If you look at the PCB for your MyECU unit, you can see if either of those pins are connected to anything on the PCB.  If the pin is empty, you can use it for connecting.

I see what you mean.  I looked at the V11 Cat version, and I see that the OEM O2 sensor uses pins 8 and 15 on the MyECU, but pin 8 is being used for something else, while pin 15 appears to be empty.  Maybe someone who has a My15M can explain what pin 8 is for.

YaBB Administrator wrote on 07/24/12 at 19:05:28:

I got confused looking at the artwork for the My15M because there was no identifier for the three pin header, and I was not sure what T8's function was.  I should have realized that R12 and R12b are the O2 input resistors.  Sorry.