Power Source Mode does not Change to ON (READY) [08/2013 - ]: Description

WARNING: This page is about a different car, the 2014 Lexus ES 300h. However, it is still accessible from the selected car via links, so may be relevant.

When the electrical key transmitter sub-assembly is in the cabin and the power switch is pressed, the power management control ECU receives a signal and changes the power source mode. In addition, when the shift lever is in P and the brake pedal is depressed, the hybrid control system can be started by pressing the power switch.

HINT:

When the power management control ECU is replaced with a new one and the cable is connected to the negative (-) auxiliary battery terminal, the power source mode changes to on (IG).
When the cable is disconnected and reconnected to the negative (-) auxiliary battery terminal, the power source mode returns to the state it was in before the cable was disconnected.