I already have a separate COP setup through TurboTunerUSB, so I will need to include new wiring from unused pins in the ECU for the logic level outputs.

I plan to leave a stock (modified for no CEL reporting) ECU in a bridge connector to retain the instrumentation & basic OBDII output for state inspection purposes

I want to retain items from the existing ME4.4 such as the AC/2 speed fan functionality, Barometric pressure compensation, dual knock sensors and Accelerometer (if possible).

The main item I have to add is the MAP/MAT (038 906 051) , I'm going to use the Bosch/VW item. I can repurpose existing wiring from the EVAP valve for that.

EDIT: ordered the 4bar MAP from the UK: 03K 906 051

The WB02 will be installed in place of the existing rear O2, I just have to add one wire to the stock harness for that.

Main Engine harness mostly ready.

WBO2 wired where Rear O2 used to go, added wire for Nerst

MAP installed in intake

IAT in intake pipe

VEMS board arrived - so assembly & install in Motronic box is next

started laying out board connections

heat sinks

Motronic wiring

Rebuilt engine is back in the wagon, so I'm ready to get back into the VEMS

a US Volvo forum member found this for me:

Which would appear to resolve my dilemma as to how to proceed with wiring for the stock IAC valve.

Finished wiring the Motherboard to the Motronic connector

Epoxied wiring to prevent issues with potential movement

Main connector in place

Now I need to start learning the software & configuration for my setup.