Engine Start Operation When Intelligent Key Is Contacted To Push-Button Ignition Switch

WARNING: This page is about a different car, the 2020 Nissan Altima. However, it is still accessible from the selected car via links, so may be relevant.

When brake pedal is depressed while selector lever is in the P (Park) position, BCM activates NATS antenna amp. that is located behind push-button ignition switch.
When Intelligent Key (transponder built-in) backside is contacted to push-button ignition switch, BCM starts NVIS (NATS) ID verification between BCM and Intelligent Key (transponder built-in) via NATS antenna amp.
When the NVIS (NATS) ID verification result is OK, buzzer in combination meter sounds and BCM transmits the result to ECM.
BCM turns ACC relay ON and transmits ignition power supply ON signal to IPDM E/R.
IPDM E/R turns the ignition relay ON and starts the ignition power supply.
BCM detects that the selector lever position is P (Park) or N (Neutral).
BCM transmits starter request signal to IPDM E/R and turns the starter relay in IPDM E/R ON if BCM judges that the engine start condition* is satisfied.
IPDM E/R turns the starter control relay ON when receiving the starter request signal.
Power supply is supplied through the starter relay and the starter control relay to operate the starter motor.
When BCM receives feedback signal from ECM indicating that the engine is started, BCM transmits a stop signal to IPDM E/R and stops cranking by turning off the starter motor relay. (If engine start is unsuccessful, cranking stops automatically within 5 seconds.)

*: For the engine start condition, refer to the table "POWER SUPPLY POSITION CHANGE TABLE BY PUSH-BUTTON IGNITION SWITCH OPERATION" below.