Sonar Control Unit (With Around View Monitor): Fail-Safe

WARNING: This page is about a different car, the 2011 Infiniti QX56. However, it is still accessible from the selected car via links, so may be relevant.

Sonar control unit has diagnosis function which can detect corner sensor malfunction and sensor harness disconnection.
It transmits the malfunction status to around view monitor control unit and informs the malfunction to the user by displaying continuously red sonar indicator.