To Keep The Blind Spot Warning/Rear Cross Traffic Alert (RCTA) System Operating Properly, Be Sure To Observe The Following Items:

WARNING: This page is about a different car, the 2018 Nissan Titan XD and 2018 Nissan Titan. However, it is still accessible from the selected car via links, so may be relevant.

System Maintenance

The side radars for the Blind Spot Warning and Rear Cross Traffic Alert (RCTA) system are located near the rear bumper.

Be sure to keep the area near the side radars clean.
Do not attach stickers (including transparent material), install accessories or apply additional paint near the side radars.
Do not strike or damage the area around the side radars.