Circuit description
WARNING: This page is about a different car, the 2014 Subaru BRZ. However, it is still accessible from the selected car via links, so may be relevant.
With the electrical key transmitter sub-assembly in the vehicle interior, press the engine switch. The collation ECM (smart key ECM ASSY) receives the signal and the power mode changes.
NOTE:
If you remove and then reconnect the battery cable, the power returns to the mode it was before you removed the cable.