So after going through the diagram for G62, it's a ground-referenced sensor (no 5VREF). Ground is grey/red pin 1, and purple/yellow pin 2 goes to ECU T105/8. The common ground for G62 is shared with G83 lower radiator temp sensor. So get your multimeter and check for pin 1 continuity to ground, and for continuity to pin 1 of the lower radiator temp sensor. If that checks out, then check for continuity of G62 pin 2 to ECU pin T105/8, and G62 pin 1 to ECU pin T105/30.
Complete wiring diagrams for the T3 have been posted
HERE by me.
View attachment 262240
Where is the actual physical ground being provided to "Sensor Ground connecton 327" ? Because that is not an actual earthing point, which would be directly connected to ground. That is just several wires connected together, which should be connected to ground, but through what connection? I was browsing through the wiring diagrams and could not find any place, where "sensor ground connection 327" is actually grounded.
So, is the ground to 327 being provided by one of the sensors themselves (for example, is pin 1 on sensor G62 connected to the body of the sensor, which is then connected to the engine and actually provides the ground to 327)? Or can the module J623 provide the ground to pin T105/30, because J623 has other actual ground connections to it?
Did you have the key on when you were testing for continuity (if ground is being provided by J623, then the key might have to be on)?
If you test for continuity between sensor G62 pin (the sensor, not the connector) and ground, what does that show you (if pin 1 on the sensor is grounded via the sensor body)? If this is the case, then unplugging G62 would remove the ground and there would be no continuity from the sensor connector pin 1 to ground.
What does the continuity look like if sensor G62 is plugged in and you test between sensor G83 connector, pin 1 and ground (if ground is provided by sensor G62)?
