Circuit/System Description

WARNING: This page is about a different car, the 2022 Cadillac CT4. However, it is still accessible from the selected car via links, so may be relevant.

The K73 Telematics Control Module provides the B24LF Mobile Telephone Microphone - Left Front with a supplied voltage on the cellular phone microphone high signal circuit 655. When the microphone is in use, voice data from the user is sent back through the K73 Telematics Control Module to the radio on the cellular microphone low reference circuit 654.

Some infotainment systems will use a secondary cellular microphone. When equipped the radio provides the B24RF Mobile Telephone Microphone - Right Front with a supplied voltage on the microphone high signal circuit 7043. When the microphone is in use, voice data from the user is sent back to the A11 Radio on the microphone low reference circuit 7044. This microphone is used for driver side hands free calling enhancement, as well as a reference microphone for the primary microphone.