OEM MK4 management wiring => Mk1/2/3 harness install FAQ (Now with added dieselness!)

Thanks for clarifying @rubjonny , and thank you for providing the documentation, saved me a load of guesswork.

Whilst going through the diagrams and comparing it with my own spreadsheet, I noticed that the speed signal doesn't go to the ECU, but in my case goes to a bare wire (my harness was cut from its donor). Going by the wiring diagrams, most of the bare wires end up at the clocks, so guessing they cut it at the cluster harness. From what I gather from looking at the speed signal:

• The speed signal comes from pin 2 on the G22 hall sensor on the gearbox.
• Goes via T14a/3.
• Ends up at pin T32/28 on the instrument cluster (J285).
• Comes back out through pin T32/3.
• Goes via T10/6 (Orange)
  
• Connects to the ECU via pin T121/54

This is a little different to what I was expecting, but if I'm correct, the ECU has to get its speed signal through the instrument cluster?
Does anyone know if the cluster is doing something to the signal in order for it to be read by the ECU, or if the wire from T14a/3 can go directly to the ECU at T121/54?

We can scope the signal coming from the hall sensor, but I don't have the instrument cluster to check the signal coming out of that, so would have to buy one. I don't mind looking for the part but would prefer it if I can avoid buying something I may not need, I want to use the Micra clocks if I can.