Power Source Mode does not Change to ON (IG and ACC): Description
WARNING: This page is about a different car, the 2011 Lexus RX 350. However, it is still accessible from the selected car via links, so may be relevant.
When the engine switch is pushed with the electrical key in the cabin, the power management control ECU receives signals to change the power source mode.
HINT:
To allow use of the Techstream to inspect the push-button start function when the power source mode is off, repeat opening and closing any of the doors. Opening and closing a door establishes communication between the Techstream and the power management control ECU. (Opening and closing a door can also be simulated by operating a door courtesy light switch.)