Hondata

I have read that the IAB is controlled differently between OBD-I and OBD-II. One sinal is 12v while this other is ground.
So if I put an OBD-I P72 on an 00 GSR the activation will not work??
Now will inverting the IAB output correct this?

No. The ECU can either ground the output or provide 12V, but not do both. If the ECUs are different you need to rewire the IAB.