I don't see the DCM firmware version by the above steps to service model. I can only use TechStream to read DCM firmware version.Yeah after a couple of go-arounds with this it seems the issue is related to the communication module that's built into the vehicle. From my understanding, the module attempts to connect back to Toyota but fails to communicate and gets stuck in an endless loop which causes the battery to drain. So the service bulletin related to a firmware update released by Toyota addresses this specific issue. I was able to confirm the software version by going into the service menu:
1. Key in the ignition to "On", but don't start the engine.
2. Power / Volume to "Off"
3. Menu --> Display --> Screen off
4. "Seek" (press 5 times) *
5. "Track" (press 5 times) *
I ended up getting the free firmware update complete as well and have not had any issues since.