[urq] Engine harness question

[n-engelbert at terrans.net]

I'm in the process of a 3b running 034 IIC swap into my early 83, and I've
got a question about the 3 wires that go from the ECU toward the fusebox
in the engine harness.  The wires are black, green/violet, and
brown/green.  I've got two of them figured out, the black is switched
power, and the green/violet is the fuel pump relay trigger.  But, what is
the brown/green (it could be brown/light green) wire?  I can't seem to
find it in the bentley using the 84 wiring diagrams.

I'd like to tear apart my interior as little as possible, and I'm thinking
about clipping the wires that go under the heater box and reusing them,
while relaying the power to the ECU using that black wire as a trigger,
since there doesn't seem to be much demand for an UrQ harness nowadays.

Thanks!

Nathan Engelbert
83 UrQ DA900453
89 90q
91 200q20v avant (wrecked)