Radio, Stereo, and Compact Disc: Description and Operation

ENTERTAINMENT SYSTEM

The entertainment system consists of the following:
- CDX6 audio unit
- two door speakers
- two rear speakers
- two center imaging speakers
- center imaging amplifier
- two subwoofer speakers in enclosures
- subwoofer amplifier (mounted on the RH subwoofer enclosure)
- antenna isolator module
- steering wheel audio controls

Normal Operation
The audio system is enabled when the key is in the RUN or ACC position. The center imaging and subwoofer speakers are powered by their own respective amplifiers. The rest of the speakers are powered by the audio unit. The steering wheel controls send information to the audio unit allowing the driver to adjust various audio controls. The audio unit contains an integral six-disc CD changer that is not repairable. The antenna isolator module reduces interference thus helping to create clear sound when the radio is in use.

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 and center imaging 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 is linked to the SCP network and therefore, trouble codes can be obtained with a diagnostic tool. The audio unit also has a self diagnostic mode that can be entered by pressing preset buttons 3 and 6 simultaneously.