Microphone Circuit [01/2019 - 03/2019]: Description

WARNING: This page does not describe the selected car, but rather 6 other vehicles, including the 2023 Toyota GR Corolla, 2023 Toyota Corolla, 2022 Toyota Corolla, 2021 Toyota Corolla, and 2020 Toyota Corolla. However, it is still accessible from the selected car via links, so may be relevant.

w/o Manual (SOS) Switch:
The radio and display receiver assembly, map light assembly and telephone microphone assembly are connected to each other using the microphone connection detection signal lines.

Using this circuit, the radio and display receiver assembly sends power to the map light assembly and telephone microphone assembly, and the map light assembly and telephone microphone assembly sends microphone signals to the radio and display receiver assembly.
w/ Manual (SOS) Switch:
The radio and display receiver assembly, map light assembly and telephone microphone assembly are connected to each other using the microphone connection detection signal lines.

Using this circuit, the DCM (telematics transceiver) sends power to the map light assembly and telephone microphone assembly, and the map light assembly and telephone microphone assembly sends microphone signals to the radio and display receiver assembly via the DCM (telematics transceiver).