Haha yeah, that's what I was trying to say - sorry I didn't articulate it that well
So I think we've got the DME side figured out pretty well. We still need to figure out where the "battery charge indicator", "engine start signal feedback", "signal oil pressure switch", and "signal oil level sensor" end up going on the MS43 cars. And the two fuel tank leak wires.
Here are the labels for those signals
X60004/Pin 1 = Signal Battery Charge Indicator (Input) = S_61--1
X60004/Pin 2 = Engine Start Signal Feedback (Input) = P_30H/S_30H (the same connection recieves both labels in different diagrams... I think S_30H is correct).
X60004/Pin 11 = Signal Oil Pressure Switch (Output) = S_OLD
X60003/Pin 26 = Signal Oil Pressure Switch (Input) = A_OLD
X60004/Pin 21 = Signal Oil Level Sensor (Output) = F_OLN
X60003/Pin 39 = Signal Oil Level Sensor (Input) = T_OLN
Edit: Okay, on MS43 cars, those signals all end up on a connector called X6011, which seems to basically splice them between the instrument cluster and the sensor.
However, one thing that's not as clear is the S_30H signal. Both the X6011 diagram and the MS43 cluster diagram show the wire going to a connector called X276. However, when you click the link for X276, it says it cannot be found. So I don't know what's going on there.
Edit 2: Okay, more digging, and it seems X276 is just a splice.
So it looks like my prediction was right, all of those connectors are going to the cluster directly now.
Edit 3: Looks like the MS42 cluster already recieved the S61--1 signal via a splice. So that wire can also be discarded on the DME end.
I realize this post is fairly unorganized, but the info is there. I'll see if I can find the time to make a clear diagram. Though I suspect Alex will beat me to the punch
Only thing left to figure out is the leak sensor. I did notice that the "AS OF 2001_09" MS43 has another leak diagnosis pin (X60003/51), but more importantly, all of the leak diagnosis pins are labeled as US Only. So it might not be important.
Edit 4: I just looked at the US MS42 Table http://wds.spaghetticoder.org/en/zinfo/E46_PA6000C.htm
There are two "leak diagnosis" pins already present on pins 30 and 34 (34 would probably have to be moved to 20)! However, on the MS43, the two pins are both labeled as "output", while on the MS42 one is out, and one is in. But there are two wires going generally to the right area. So even if there's an electronic component that has to be retrofitted, it can be done with minimal work. Or you can just disable it via euro tune.