Ok I thought it might be the 5R55E tranny.

My manual shows the N/Start switch to be on the drivers side, locacted between & above the shift cable bracket & where the shift cabe end, connects to the tranny.

It's sort of round shaped, with a hex body & electrical connector on the end.

Not sure where the OD solenoid connector is located, but it's probably more toward the front of the tranny, closer to the torque converter, but someone else will have to pinpoint it for us.