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Audio System

AUDIO
An audio system is standard factory-installed equipment on this model. The standard equipment audio system includes an AM/FM/cassette (RAS sales code) radio receiver, and speakers in six locations. Several combinations of radio receivers and speaker systems are offered as optional equipment on this model. The audio system uses an ignition switched source of battery current so that the system will only operate when the ignition switch is in the ON or Accessory positions.

A Compact Disc (CD) changer with a ten disc magazine, remote radio switches with six functions mounted to the backs of the steering wheel spokes, and a memory system that automatically stores and recalls up to twenty radio station presets (ten AM and ten FM) and the last station listened to for two drivers are optional factory-installed equipment on this model. Refer to Electrical, Power Seats for more information on the memory system.

The audio system includes the following components:
- Antenna
- Compact disc changer (available with RBN sales code radio receivers only)
- Power amplifier (with premium speaker system only)
- Radio noise suppression components
- Radio receiver
- Remote radio switches
- Speakers

Certain functions and features of the audio system rely upon resources shared with other electronic modules in the vehicle over the Programmable Communications Interface (PCI) data bus network. The PCI data bus network allows the sharing of sensor information. This helps to reduce wire harness complexity, internal controller hardware, and component sensor current loads. At the same time, this system provides increased reliability, enhanced diagnostics, and allows the addition of many new feature capabilities. For diagnosis of these electronic modules or of the PCI data bus network, the use of a DRB scan tool and the proper Diagnostic Procedures are recommended.

The other electronic modules that may affect audio system operation are as follows:
- Body Control Module (BCM) - (Refer to CENTRAL TIMER MODULE - DESCRIPTION) for more information.
- Driver Door Module (DDM) (Refer to DRIVER DOOR MODULE - DESCRIPTION) for more information,
- Passenger Door Module (PDM) (Refer to DRIVER DOOR MODULE - DESCRIPTION) for more information.

The audio system includes the following major components, which are described in further detail elsewhere in this service information:
- Amplifier - On models equipped with the optional premium speaker system, an audio power amplifier is located on the rear floor panel underneath the left end of the rear seat cushion in the passenger compartment.
- Antenna Body and Cable - The most visible component of the antenna body and cable are the antenna adapter and the antenna cap nut, which are located on the top of the right front fender panel of the vehicle, near the right end of the cowl plenum.
- Antenna Mast - The antenna mast is a metal rod that extends upward from the antenna body and cable on the top of the right front fender panel of the vehicle, near the right end of the cowl plenum.
- Radio - The radio for this model is located in the instrument panel center stack area, inboard of the instrument cluster and above the heater and air conditioner controls.
- Radio Noise Suppression Ground Strap - A radio noise suppression ground strap is installed between the rear of the engine cylinder head and the dash panel sheet metal in the engine compartment.
- Speaker - The standard speaker system includes four speakers in four locations, while the premium speaker system includes six speakers in six locations.

Hard wired circuitry connects the audio system components to each other through the electrical system of the vehicle. These hard wired circuits are integral to several wire harnesses, which are routed throughout the vehicle and retained by many different methods. These circuits may be connected to each other, to the vehicle electrical system and to the audio system components through the use of a combination of soldered splices, splice block connectors and many different types of wire harness terminal connectors and insulators. Refer to the appropriate wiring information for complete standard and premium audio system circuit diagrams. The wiring information includes proper wire and connector repair procedures, further details on wire harness routing and retention, as well as pin-out and location views for the various wire harness connectors, splices, and grounds.

The audio system components are designed to provide audio entertainment and information through the reception, tuning and amplification of locally broadcast radio signals in both the Amplitude Modulating (AM) and Frequency Modulating (FM) commercial frequency ranges. Electromagnetic radio signals that are broadcast from a radio station induce electrical modulations into the audio system antenna mast. The antenna body and cable conduct these weak signals from the antenna mast to the radio. The radio then tunes and amplifies these weak signals into stronger electrical signals that are required in order to operate the audio system speakers. The speakers convert these electrical signals into air movement, which reproduces the sounds being broadcast by the radio station.

Some audio systems also offer the user the option of selecting from and listening to prerecorded audio cassette tapes, audio compact discs, or both. Regardless of the media type, the audio system components provide the user with the ability to electronically amplify and adjust the audio signals being reproduced by the speakers within the vehicle to suit the preferences of the vehicle occupants.

The audio system components operate on battery current received through a fuse in the Junction Block (JB) on a fused ignition switch output (run-acc) circuit so that the system will only operate when the ignition switch is in the ON or Accessory positions.

On vehicles that are equipped with the optional remote radio switches, the BCM receives hard wired resistor multiplexed inputs from the remote radio switches. The programming in the BCM allows it to process those inputs and send the proper messages to the radio receiver over the PCI data bus to control the radio volume up or down, station seek up or down, preset station advance, and mode advance functions.

On vehicles equipped with the optional memory system, when the DDM receives a Driver 1 or Driver 2 memory recall input from the memory switch on the driver side front door trim panel or a memory recall message from the Remote Keyless Entry (RKE) receiver in the PDM, the DDM sends a memory recall message back to the radio receiver over the PCI data bus to recall the radio station presets and last station listened to information.

See the owner's manual in the vehicle glove box for more information on the features, use and operation of each of the available audio systems.

AMPLIFIER
Models equipped with the Infinity premium speaker package have a separate power amplifier unit. This power amplifier is rated at 180 watts out-put. The power amplifier unit is mounted to the rear floor panel under the passenger side rear seat cushion. The power amplifier unit can be accessed for service by unlatching and tilting the passenger side rear seat cushion forward.

The power amplifier unit should be checked if there is no sound output noted from the speakers. For diagnosis of the power amplifier, (Refer to SPEAKER - DIAGNOSIS AND TESTING). The power amplifier cannot be repaired or adjusted and, if faulty or damaged, the unit must be replaced.

The power amplifier is energized by a fused 12 volt output from the radio receiver whenever the radio is turned ON. The power amplifier receives the sound signal inputs for four speaker channels from the radio receiver, then sends the amplified speaker outputs for each of those channels to the six Infinity speakers. For complete circuit diagrams, refer to the appropriate wiring information. The wiring information includes wiring diagrams, proper wire and connector repair procedures, details of wire harness routing and retention, connector pin-out information and location views for the various wire harness connectors, splices and grounds.

Fig.5 Antenna Body And Cable:




ANTENNA BODY & CABLE
The antenna body and cable are not readily visible in their installed positions in the vehicle. The most visible component of the antenna body and cable are the antenna adapter and the antenna cap nut, which are located on the top of the right front fender panel of the vehicle, near the right end of the cowl plenum. The antenna body and cable are secured below the fender panel by the antenna cap nut through a prefabricated and dedicated mounting hole in the top of the right front fender. The primary coaxial antenna cable is then routed beneath the fender sheet metal and through a prefabricated and dedicated cable entry hole in the right cowl side panel into the interior of the vehicle. Inside the vehicle, the primary coaxial cable is connected to a secondary instrument panel antenna coaxial cable with an in-line connector that is located behind the right end of the instrument panel. The secondary coaxial cable is then routed behind the instrument panel to the back of the radio. Vehicles ordered with the radio delete option have a molded plastic plug installed in the antenna mounting hole on the right front fender, and a plastic plug installed in the cable entry hole of the right cowl side panel in place of the antenna body and cable.

The factory-installed radio antenna body and cable consists of the following components:
- Antenna adapter - The antenna adapter is sometimes also referred to as the antenna bezel or escutcheon.
- Antenna body - The die cast white metal antenna body is the mating structure between the antenna mast and the primary antenna coaxial cable.
- Antenna cable - This vehicle uses a two-piece antenna coaxial cable. The primary antenna cable is integral to the antenna body, and the secondary antenna cable connects the primary cable to the radio.
- Antenna cap nut - The antenna cap nut is a special, bright-plated threaded fastener that captures the antenna adapter and retains the antenna body to the fender sheet metal.

The components of the radio antenna body and cable cannot be adjusted or repaired. All factory-installed radios automatically compensate for radio antenna trim. Therefore, no antenna trimmer adjustment is required or possible after replacing the antenna body and cable or the radio. If an antenna body and cable component is damaged or faulty, it must be replaced. Other than the primary antenna cable, which is integral to the antenna body, the individual components of the antenna are available for service replacement.

The antenna body and cable connects the antenna mast to the radio. The radio antenna is an electromagnetic circuit component used to capture radio frequency signals that are broadcast by local commercial radio stations in both the Amplitude Modulating (AM) and Frequency Modulating (FM) frequency ranges. These electromagnetic radio frequency signals induce small electrical modulations into the antenna as they move past the mast. The antenna body transfers the weak electromagnetic radio waves induced into the rigid antenna mast into the center conductor of the flexible primary antenna coaxial cable. The braided outer shield of the antenna coaxial cable is grounded through both the antenna body and the radio chassis, effectively shielding the radio waves as they are conducted to the radio. The radio then tunes and amplifies the weak radio signals into stronger electrical signals in order to operate the audio system speakers.

The antenna body includes an integral flange that mates with and grounds the antenna body to the underside of the fender panel sheet metal. Above the fender panel, the antenna body has a short nipple that is externally threaded to accept the antenna cap nut. Inside the nipple is a plastic insulator tube, and inside this insulator is an internally threaded metal receptacle that accepts the adapter stud on the bottom of the antenna mast. The antenna adapter serves as an above fender interface to mount and secure the antenna body to the vehicle. The antenna adapter is a black molded plastic component that provides a functional transition between the top of the fender and the antenna cap nut, while concealing the edges of the antenna mounting hole and protecting the painted finish of the fender from marring as the antenna cap nut is tightened. The adapter is installed over and shrouds the threaded nipple of the antenna body, which is installed from under and protrudes through the top of the mounting hole in the fender. The antenna cap nut is installed on top of the antenna adapter and tightened onto the external threads of the antenna body nipple to effectively secure and ground the antenna body to the fender. Three notches on the outer circumference of the cap nut are engaged by matching projections of an antenna nut wrench (Special Tool C-4816) to facilitate the removal and installation of this special fastener. Proper tightening of the antenna cap nut is critical to ensuring proper grounding of the antenna body to the fender sheet metal, which is necessary for clear radio signal reception.

A short length of coaxial cable serves as the primary antenna cable. The center conductor of the cable is connected to the antenna mast receptacle. The outer wire mesh of the cable is connected to and grounded through the antenna body. One end of the primary antenna cable is securely crimped to the lower end of the antenna body, while the opposite end features a simple push/pull-type male coaxial cable connector that serves as the in-line connector to the instrument panel (secondary) antenna coaxial cable. The primary coaxial cable includes a grommet that seals the cable to an entry hole in the right cowl side outer panel where the cable passes into the passenger compartment of the vehicle. The secondary antenna cable has a push/pull-type male coaxial cable connector on the radio end, and a push/pull-type female coaxial cable connector on the opposite end, which serves as the in-line connector to the primary antenna cable. In the passenger compartment the primary cable is routed to the lower right side of the instrument panel, where it is connected to the secondary instrument panel antenna cable. The instrument panel antenna cable is routed near the instrument panel wire harness through the instrument panel to the radio and is secured to the instrument panel structural support with small metal push-on retainers. This two-piece antenna cable arrangement allows the instrument panel or the antenna body and cable to be removed or installed without disturbing the radio.

CD CHANGER
A factory-installed Compact Disc (CD) changer featuring a ten-CD magazine is an available option on this model when it is also equipped with the premium speaker package and a radio receiver including the CD controls feature. The CD changer is mounted in the cargo area of the passenger compartment on the right rear quarter panel. It is concealed behind a molded plastic bin with an integral hinged and latching lid that matches the interior trim of the vehicle.

The CD changer is connected to a take out from the right body wire harness and receives both ground and radio-switched battery current through the radio receiver. The controls on the radio receiver operate the CD changer through messages sent over the Programmable Communications Interface (PCI) data bus network. The two-channel audio outputs of the CD changer are hard wired back to the radio receiver, which then outputs the signal through four channels to the power amplifier. For diagnosis of the messaging functions of the radio receiver and the CD changer, or of the PCI data bus, a DRB scan tool and the proper Diagnostic Procedures are required.

The CD changer can only be serviced by an authorized radio repair station. See the latest Warranty Policies and Procedures for a current listing of authorized radio repair stations. Refer to the appropriate wiring information. The wiring information includes wiring diagrams, proper wire and connector repair procedures, details of wire harness routing and retention, connector pin-out information and location views for the various wire harness connectors, splices and grounds.

The CD changer will only operate when the ignition switch is in the ON or Accessory positions, and the radio is turned ON. For more information on the features, loading procedures and radio control functions for the operation of the CD changer, see the owner's manual in the vehicle glove box.

RADIO
Available factory-installed radio receivers for this model include an AM(/FM/cassette (RAS sales code), an AM/FM/cassette/3-band graphic equalizer with CD changer control feature (RBN sales code), or an AM/FM/CD/cassette/3-band graphic equalizer (RAZ sales code). All factory-installed radio receivers, except the RAS sales code, can communicate on the Programmable Communications Interface (PCI) data bus network through a separate wire harness connector. All factory-installed receivers are stereo Electronically Tuned Radios (ETR) and include an electronic digital clock function.

These radio receivers can only be serviced by an authorized radio repair station. See the latest Warranty Policies and Procedures for a current listing of authorized radio repair stations.

Fig.10 Radio Code - Typical:




All factory-installed radios are readily identifiable by a three-digit alphabetical sales code, which is imprinted on the face plate lens just below a Pentastar logo.

All vehicles are equipped with an Ignition-Off Draw (IOD) fuse that is removed when the vehicle is shipped from the factory. This fuse feeds various accessories that require battery current when the ignition switch is in the OFF position, including the clock. The IOD fuse is removed to prevent battery discharge during vehicle storage.

When removing or installing the IOD fuse, it is important that the ignition switch be in the OFF position. Failure to place the ignition switch in the OFF position can cause the radio display to become scrambled when the IOD fuse is removed and replaced. Removing and replacing the IOD fuse again, with the ignition switch in the OFF position, will correct the scrambled display condition.

The IOD fuse should be checked if the radio or clock displays are inoperative. The IOD fuse is located in the Power Distribution Center (PDC). Refer to the fuse layout label on the underside of the PDC cover for IOD fuse identification and location.

The radio receiver operates on ignition switched battery current that is available only when the ignition switch is in the ON or Accessory positions. The electronic digital clock function of the radio operates on fused battery current supplied through the IOD fuse, regardless of the ignition switch position.

For more information on the features, setting procedures, and control functions for each of the available factory-installed radio receivers, see the owner 5 manual in the vehicle glove box. For complete circuit diagrams, refer to the appropriate wiring information. The wiring information includes wiring diagrams, proper wire and connector repair procedures, details of wire harness routing and retention, connector pin-out information and location views for the various wire harness connectors, splices and grounds.

RADIO NOISE SUPPRESSION GROUND STRAP
Radio Frequency Interference (RFI) and Electro-Magnetic Interference (EMI) noise suppression is accomplished primarily through circuitry internal to the radio receivers. These internal suppression devices are only serviced as part of the radio receiver.

External suppression devices that are used on this vehicle to control RFI or EMI noise include the following:
- Radio antenna base ground
- Radio receiver chassis ground wire or strap
- Engine-to-body ground strap(s)
- Exhaust system-to-body and transmission ground strap (4.7L engines only)
- Resistor-type spark plugs
- Radio suppression-type secondary ignition wiring.

For more information on the spark plugs and secondary ignition components, refer to Ignition System in Ignition System.

Fig.14 Remote Radio Switches:




REMOTE SWITCHES
Remote radio control switches are included on models equipped with the optional leather-wrapped steering wheel. The two rocker-type switch units are mounted in the upper spoke covers of the rear (instrument panel side) steering wheel trim cover. The switch unit on the left side is the seek switch and has seek up, seek down, and preset station advance switch functions. The switch unit on the right side is the volume control switch and has volume up, volume down, and mode advance switch functions.

The two remote radio switch units are each retained in a mounting hole located on opposite sides of the rear steering wheel trim cover by four integral snap features. A plastic bracket on the back of each switch unit provides additional support for the unit by extending towards the center of the steering wheel where it is clamped between the steering wheel armature and the steering wheel rear trim cover mounting boss by the trim cover mounting screw.

The two remote radio switch units share a common steering wheel wire harness with the vehicle speed control switches. The steering wheel wire harness is connected to the instrument panel wire harness through the clockspring. (Refer to CLOCKSPRING - DESCRIPTION) for more information on this component.

For complete circuit diagrams, refer to the appropriate wiring information. The wiring information includes wiring diagrams, proper wire and connector repair procedures, details of wire harness routing and retention, connector pin-out information and location views for the various wire harness connectors, splices and grounds.

The six switches in the two remote radio switch units are normally open, resistor multiplexed momentary switches that are hard wired to the Body Control Module (BCM) through the clockspring. The BCM sends a five volt reference signal to both switch units on one circuit, and senses the status of all of the switches by reading the voltage drop on a second circuit.

When the BCM senses an input (voltage drop) from any one of the remote radio switches, it sends the proper switch status messages on the Programmable Communication Interface (PCI) data bus network to the radio receiver. The electronic circuitry within the radio receiver is programmed to respond to these remote radio switch status messages by adjusting the radio settings as requested. For diagnosis of the BCM or the PCI data bus, the use of a DRB scan tool and the proper Diagnostic Procedures are recommended.

For more information on the features and control functions for each of the remote radio switches, see the owner's manual in the vehicle glove box.

SPEAKER
Standard
The standard equipment speaker system includes speakers in six locations. One 6.4 centimeter (2.50 inch) diameter tweeter is installed on each end of the instrument panel top pad. One 15.2 by 22.9 centimeter (6 by 9 inch) full-range speaker is located in each front door. There is also one full-range 16.5 centimeter (6.5 inch) diameter full-range speaker located in each rear door.

Premium
The optional premium speaker system features six Infinity model speakers in six locations. Each of the standard speakers is replaced with Infinity model speakers. One 6.4 centimeter (2.50 inch) diameter Infinity tweeter is installed on each end of the instrument panel top pad. One 15.2 by 22.9 centimeter (6 by 9 inch) Infinity woofer is located in each front door. There is also one full-range 16.5 centimeter (6.5 inch) diameter Infinity full-range speaker located in each rear door. The premium speaker system also includes an additional Infinity power amplifier. The total available power of the premium speaker system is about 180 watts.

Standard
Each of the two tweeters and four full-range speakers used in the standard speaker system is driven by the amplifier that is integral to the factory-installed radio receiver. For complete circuit diagrams, refer to the appropriate wiring information. The wiring information includes wiring diagrams, proper wire and connector repair procedures, details of wire harness routing and retention, connector pin-out information and location views for the various wire harness connectors, splices and grounds.

Premium
The six Infinity speakers used in the premium speaker system are all driven by the radio receiver through an Infinity power amplifier. For complete circuit diagrams, refer to the appropriate wiring information. The wiring information includes wiring diagrams, proper wire and connector repair procedures, details of wire harness routing and retention, connector pin-out information and location views for the various wire harness connectors, splices and grounds.