[Plums]

I used a VY loom. The colours coming from the Neutral start switch are Grey/Blue, Grey, Black/Red, Brown/Blue, Light Green.

The GY/BLU went to the Powertrain Interface Module and the GY went to the start relay. (I now have GY/BLU going to earth and GY going to the start relay.)
I know that the PIM sends the GY/BLU wire to earth after a valid signal from the PCM. What does the PIM do to the GY/BLU wire once the engine is running???

The BLK/R goes to earth.

The BR/BLU and LG wires are for the reverse lights. (I don't have these connected)

With the ignition on and the scanner running, (logging PRNDL status), the PRNDL status remains in PARK regardless of shifter position.