The G37/370 oil temperature is an EXTENDED PID and the ECU needs to be in to diagnostic mode in order to recieive a valid response. This is very easy to do.
This video show how to set up the engine oil temperature PID for our cars using Torque Pro:
If your OBD software/app doesn't allow a diagnosticstart/stop code this won't work.
If you want to learn more about OBD PIDs for the VQ37VHR have a look at:
https://www.youtube.com/OBD4Everyone