Scheme 1
Scheme 2
Normal Operation
The audio system and DVD player are enabled when the key is in the ON or ACC position. 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 CDX6 or DM100i are not repairable. The antenna module reduces interference thus helping to create clear sound when the radio is in use. The audio unit has a partial mute for optional reverse sensing system (if equipped). For additional information refer to the owner literature.
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 is linked to the SCP network, 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. 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.
Refer to RADIO wiring diagrams for schematic and connector information.
Scheme 3
Scheme 4
- Verify the customer concern by operating the audio system with the engine running and the vehicle in and out of motion.
- Visually inspect for obvious signs of mechanical and electrical damage.
- If the concern is visually evident, proceed to the Symptom Chart.
- If the concern is not visually evident, proceed to speaker walk-around test and audio unit self-diagnostic mode.
When the key is in the ON position and the audio unit is turned on, communication occurs between the diagnostic tool and the audio unit. The diagnostic tool retrieves codes and data.
The antenna receives AM and FM radio waves. The antenna is a conductive wire concealed on the inside of the rear quarter window glass. Radio waves are sent to the audio unit through the antenna lead-in cable.
The radio suppression equipment reduces interference transmitted through the radio 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. Remove any paint or dirt from between a component and its ground. Tighten all connectors and screws securely according to the torque specifications. Refer to the SPECIFICATION CHART .
The audio unit directs the audio signals to the speakers through separate positive and negative circuits for each of the four audio channels: LF, RF, LR, and RR. The audio unit provides internal circuit protection for shorts to ground, shorts to B+ battery or shorts between any output circuits.
The audio unit directs the audio signals to the speakers through separate positive and negative circuits for each of the four audio channels: LF, RF, LR, and RR. The audio unit provides internal circuit protection for shorts to ground, shorts to B+ battery or shorts between any output circuits.
The subwoofer speakers are powered from a separate subwoofer amplifier. The clip detection circuit, 168 (RD/BK), carries out two functions; to turn on the subwoofer amplifier, and to indicate to the audio unit when the subwoofer output distortion signal reaches a damaging level. The audio unit then reduces the audio output signal to the subwoofer amplifier.
The steering wheel audio controls consist of a specific resistor value for each button function, creating a voltage divider. When a button is pressed, a specific reference voltage is sent to the audio unit. The audio unit then uses this reference voltage to determine which control input function has been selected. Circuit 595 (LB/RD) is the reference voltage circuit between the steering wheel audio controls and the audio unit. The ground circuit for the steering wheel audio controls is through the steering column and speed control servo.
The START input circuit 1000 (RD/BK) is sent to the audio unit when the ignition switch is turned to the START position. The audio unit then immediately mutes all speaker amplifier outputs and the subwoofer amplifier enable circuit output to eliminate the possibility of speaker pops during engine cranking.
When the key is turned to the ON or ACC position, power is supplied to the DVD unit and serves as a wake up signal. Once the DVD unit is powered up, a signal is sent to the audio unit through circuit 1068 so that communication between the audio unit and DVD unit can begin. When a video disc is inserted into the DVD unit and the PLAY button is pressed, an image should be displayed on the screen.
When a movie is being played using the DVD player, sound should be heard through all four speakers and the subwoofer.
The audio unit directs the audio signals to the 8 channel amplifier and then to the speakers through separate positive and negative circuits for each of the five audio channels: LF, RF, LR, RR, and the subwoofer. The audio unit provides internal circuit protection for shorts to ground, shorts to B+ battery or shorts between any output circuits as well as providing a power on signal to the amplifier. Circuit 173 (DG/VT) sends an enable signal to the 8 channel amplifier.
The audio unit directs the audio signals to the 8 channel amplifier and then to the speakers through separate positive and negative circuits for each of the five audio channels: LF, RF, LR, RR, and the subwoofer. The audio unit provides internal circuit protection for shorts to ground, shorts to B+ battery or shorts between any output circuits as well as providing a power on signal to the amplifier. Circuit 173 (DG/VT) sends an enable signal to the 8 channel amplifier.
The subwoofer speakers are powered by the same audio unit amplifier that powers the door speakers. Circuit 173 (DG/VT) sends an enable signal to the audio unit amplifier.