Could anybody be of assistance and provide me with a location for the ECM D131?

Well I found the ECM, under the plastic thing near the windscreen. I removed the three connectors and performed continuity checks for the wires from the throttle body controller.

I have found good connection on all wires apart from, the blue with white tracer and the solid brown....

Click image to enlarge

To update: I found a connection on the solid brown so rechecked all the blue with whites, and yes the one from the throttle body had no connection. I checked the wire from the throttle pedal and found it’s pin and did the same for the turbo boost sensor, thus leaving me convinced I had a bad wire from the throttle
Body to the ECM. So I piggy- backed the wire and ran a new wire loose in the engine bay. A quick run down the road revealed a big improvement but the fault has not gone in its entirety!!!

I will test all wires from the MAF next, and then might well revert back to the turbo solenoid and it’s wiring.

I am intrigued though because I cannot see where any chaffing will have occurred on the wiring loom, it barely passes through one bulkhead with no other connectors on the way, so how I have a bad connection I am still confused by!!

Reading the stuttering/Juddering/Hesitation thread as pinned at the top of the technical forum, I wonder if I have in fact got two faults here, the stuttering juddering at slow speed acceleration, seems more related to the Haldex unit?

I see a service kit is £65 approx so ordered one of those. I've never touched that unit in the whole time I've owned it, so if nothing else it's due an oil change @ 95k.

Well a little update - I serviced the haldex, made no difference and the oil was clean anyway. So I turned may attention back to the turbo controller. I removed it before and found it to be working, so tested the wiring down to it and had continuity.

I read a whole bunch of stuff on these Hella units, and it seems if the plastic worm gear is worn it can cause a whole host of issues. So I threw a new turbo controller at it, and the problem disappeared!!

I assume I had two issues running side by side, with the broken wire and the error within the turbo controller. Either way I've had my share of issues here, and decided to part company with the car.