Radio, Stereo, and Compact Disc: Description and Operation

ENTERTAINMENT SYSTEM

Normal Operation
The audio system and digital versatile disc (DVD) player are enabled when the key is in the RUN or ACC position. The speakers are powered by the audio unit and the subwoofer is powered by its own amplifier. The steering wheel controls send information to the audio unit allowing the driver to adjust various audio controls. The audio unit can contain an integral six-disc CD changer (CD6) or the vehicle can be equipped with one of the following audio units that is not repairable: the M100CD AM/FM/CD (single CD) or the DM100 AM/FM/CD/cassette (premium). The subwoofer is available with the CD6 Audiophile option while the DVD is available with the CD6 and DM100.

PRINCIPLES OF OPERATION

When the audio unit is powered, up a wake-up signal is sent to the subwoofer amplifier. Audio output signals are then sent continuously to the subwoofer amplifier. These signals are then amplified and sent to the speakers as a fluctuating AC voltage thus producing sound from the speakers. A fluctuating AC voltage, audio signal is also sent to the remaining speakers, directly from the audio unit, to produce sound. The steering wheel controls are a multiplexed system that use different resistor values to produce different voltage levels on a single circuit. Each button that is pressed results in a unique voltage signal at the audio unit. This voltage signal is then interpreted by the audio unit as a distinct command. The audio unit has a self diagnostic mode that can be entered by pressing preset buttons 3 and 6 simultaneously. The DVD player sends fluctuating AC voltage audio output signals to the audio unit. These signals are then amplified by the audio unit and sent to the speakers.