DeVille V8-4.6L VIN Y (1998)
Cellular Phone: Description and Operation
Circuit Operation
Power is supplied from the Radio/Phone Fuse in the rear compartment fuse block via CKT 40 (ORN) to the cellular telephone module connector at
terminal A. The module is grounded at terminal B via CKT 1051 (BLK) to ground G400.
The cellular telephone module contains the cellular telephone transceiver and the cellular telephone modem. The module controls the cellular telephone
handset power via CKT 1941 (BRN) and regulated 8 volt power CKT 1266 (RED). The module controls the handset display and receives
handset/keypad data on CKT 679 (PPL), CKT 1156 (PPL/WHT) and CKT 1798 (GRY/BLK).
Power is supplied to the cellular telephone handset at terminal 5 from the Radio/Phone Fuse in the rear compartment fuse block via CKT 40 (ORN). The
handset is grounded at terminal 10 via CKT 1051 (BLK) to ground G400. The handset contains a keypad, display, microphone and ear speaker. The
handset communicates shielded signals to the cellular telephone module as follows:
^
Mouthpiece audio CKT 1153 (LT BLU).
^
Earpiece audio CKT 1154 (DK BLU).
^
Audio ground CKT 1235 (LT BLU/BLK).
When the handset is placed in its docking cup, the phone operates in the hands-free mode. This mode allows the driver's voice to be received by the
roof-mounted microphone. During hands-free mode, the vehicle radio mutes and the incoming cellular telephone audio is routed through the radio's
speakers. When the handset is removed from its cup, the hands-free feature is disabled and the radio is unmuted. The handset must be held to the driver's
head for voice conversation.
The cellular telephone microphone is wired to the cellular telephone module via CKT 655 (GRY) and CKT 814 (NAT). During hands-free operation, the
module provides mono audio output to the vehicle audio system on CKT 658 (DK BLU) and CKT 659 (BLU/BLK).
The module communicates on the Class 2 serial data line CKT 1807 (PPL), which the module uses for transmission of messages, status and diagnostic
information.
