Push-Button Ignition Switch: Description
WARNING: This page is about a different car, the 2010 Infiniti G37. However, it is still accessible from the selected car via links, so may be relevant.
BCM transmits the change in the power supply position with the push-button ignition switch to IPDM E/R via CAN communication line. IPDM E/R transmits the power supply position status via CAN communication line to BCM.