Channel Check Diagnostics
WARNING: This page is about a different car, the 2009 Nissan Sentra. However, it is still accessible from the selected car via links, so may be relevant.
Press the "TUNE" up switch to enter channel check diagnostics. The self-diagnosis function will then display each of the four channels (FL, FR, RL, RR) for 1 second while sending a tone to each channel displayed.