NATS Antenna Amp.
WARNING: This page is about a different car, the 2018 Nissan Maxima. However, it is still accessible from the selected car via links, so may be relevant.
The ID verification is performed between BCM and transponder integrated into Intelligent Key via NATS antenna amp. when Intelligent Key backside is contacted to push-button ignition switch, in case that Intelligent Key battery is discharged. If the ID verification result is OK, the operation of starting engine is available.