Radio, Stereo, and Compact Disc: Description and Operation

ENTERTAINMENT SYSTEM

Normal Operation
The audio system and DVD player are enabled when the key is in the RUN or ACCESSORY position. The speakers are powered by the audio unit. The subwoofer is powered by its own amplifier. Driver commands through the steering wheel controls allow 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: AM/FM Radio Premium Single CD (AM/FM/CD), or Premium Dual Media (AM/FM/CD/cassette). The subwoofer is available with the CD6 Audiophile option. The digital versatile disc (DVD) is available with all the radios (Super Crew) except AM/FM radio.

Principles Of Operation
A fluctuating AC voltage audio signal is sent to the speakers, directly from the audio unit to produce sound. With the audio unit 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, producing sound from the speakers. 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 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. The audio unit also has a self diagnostic mode that can be entered by pressing preset buttons 3 and 6 simultaneously.