Microphone Signal Circuit: Description

WARNING: This page is about a different car, the 2013 Infiniti M56 and 2013 Infiniti M37. However, it is still accessible from the selected car via links, so may be relevant.

TCU supplies power to the microphone when receiving a microphone ON signal from the AV control unit.
The microphone transmits an audio signal to TCU.
TCU transmits a received sound signal to the AV control unit.