System Diagram

WARNING: This page is about a different car, the 2022 Nissan Rogue. However, it is still accessible from the selected car via links, so may be relevant.

Courtesy of NISSAN NORTH AMERICA, INC.

Component	Function
Intelligent Key	Operates based on the results of electronic ID verification using two-way communication between the Intelligent Key and the vehicle (Intelligent Key unit).
Push-button ignition switch	Refer to Push-button Ignition Switch .
Stop lamp switch	Stop lamp switch detects that brake pedal is depressed, and then transmits ON/OFF signal to BCM.
TCM	Transmits shift position signal and cranking enable signal to BCM via CAN communication.
Intelligent Key unit	Transmits push-button ignition switch status signal to BCM via CAN communication.
ABS actuator and electric unit (control unit)	Transmits vehicle speed signal to BCM via CAN communication.
BCM	BCM controls the each relay, judged from each switch status. BCM transmits the ignition ON signal to IPDM E/R via CAN communication, judged from each switch status.
Ignition relay-1	Controlled by BCM and turns ON/OFF the battery power supply to each parts.
Accessory relay
Ignition relay-2
Ignition relay-3
IPDM E/R	IPDM E/R controls the integrated ignition relay, and supplies voltage to the load according to the request from BCM via CAN communication.