Unified Meter and A/C Amp
WARNING: This page is about a different car, the 2007 Nissan Maxima. However, it is still accessible from the selected car via links, so may be relevant.
The unified meter and A/C amp. supplies speed signals to the Bluetooth control unit. Vehicle speed signals are used to determine which voice command functions will be disabled based on driving conditions.
Courtesy of NISSAN MOTOR CO., U.S.A.