Entertainment Systems: Description and Operation
ENTERTAINMENT SYSTEM
See the Tribute Wiring Diagram for schematic information.
Principles of Operation
Audio Control Module (ACM)
The audio control module (ACM) can be operated with the ignition in RUN or ACC. The accessory delay feature allows the audio system to be operated for a preset period of time after the ignition is turned off and a front door has not been opened. The ACM sends AC voltage audio signals to the speakers or to the amplifier, depending on vehicle configuration. The ACM can produce its own DTCs, which can be communicated to the scan tool through the medium speed controller area network (MS-CAN).
Front Display Interface Module (FDIM)
The front display interface module (FDIM) is a stand-alone module. It receives messages for all of its displays, which include:
- Audio information
- Climate control fan speed and temperature setting
- Outside air temperature (if equipped)
- Compass heading (if equipped)
Front Controls Interface Module (FCIM)
The front controls interface module (FCIM) acts as a customer interface with the audio system. The FCIM sends messages over the MS-CAN when any button is pressed.
Satellite Audio
The satellite audio system consists of a satellite digital audio receiver system (SDARS) module, a satellite radio antenna, and a satellite radio antenna cable. For early build vehicles, an external SDARS module is utilized. For late build vehicles, the SDARS module is built-in to the ACM. The satellite radio antenna receives digital audio signals and sends them to the SDARS module (early build) or to the ACM (late build).
Antenna - AM/FM
The fixed-mast antenna receives AM/FM radio waves and sends them to the ACM via the antenna co-axial cable.
Subwoofer
The subwoofer and amplifier are integral. The enable/clip detection circuit carries out 2 functions: to turn the amplifier on, and to indicate to the ACM when the subwoofer output distortion signal reaches a damaging level. The ACM then clips the audio output signal to prevent damage to the subwoofer.
Audio Input Jack
The audio input jack allows for a portable MP3 player to be connected to the vehicle audio system. When a portable MP3 player is connected, audio from the MP3 player can be played through the vehicle speakers.
Noise Suppression Equipment
The radio frequency suppression equipment reduces interference transmitted through the speakers by the engine ignition and electrical systems. When installing any new radio suppression equipment components, make sure that a good contact is made at all connections.
Steering Wheel Controls
The steering wheel controls consist of a series of resistors. Each steering wheel control switch function corresponds with a specific resistance value within the switch. When a switch is pressed, the ACM monitors the change in reference voltage to determine the requested function.
Network Communication
The following audio system components communicate via the MS-CAN:
- ACM
- SDARS module
- FDIM
- FCIM
The following messages are utilized by the audio system:
