Component Description

ANTENNA BODY AND CABLE
All models use a fixed-length stainless steel rodtype antenna mast, installed at the right front fender of the vehicle. The antenna mast is connected to the center wire of the coaxial antenna cable, and is not grounded to any part of the vehicle.

To minimize static, the antenna base must have a good ground. The coaxial antenna cable shield (the outer wire mesh of the cable) is grounded to the antenna base and the radio chassis.

The antenna coaxial cable has an additional disconnect, located near the right end of the instrument panel. This additional disconnect allows the instrument panel assembly to be removed and installed without removing the radio.

The factory-installed Electronically Tuned Radios (ETRs) automatically compensate for radio antenna trim. Therefore, no antenna trimmer adjustment is required or possible when replacing the receiver or the antenna.

ANTENNA MODULE- EXPORT
The antenna module is an electromagnetic circuit component designed to capture and enhance RF (Radio Frequency) signals in both the AM and FM broadcast bands. The antenna module is mounted to the right rear roof rail under the headliner. The module is grounded through the mounting bracket and fastener. The module has a two wire electrical connector that connects to the integral radio antenna, located on the right rear quarter glass. There is also an electrical connector for battery voltage and a coax cable connector.

The antenna module receives both AM and FM radio signals supplied by the side window integral radio antenna system and selectively amplifies them. The amplified signal is then sent through the body length coax cable to the radio input.

CD CHANGER
The 4 Disc In-Dash CD Changer (if equipped) is located in the instrument panel below the radio. The remote changer does not use a cartridge or magazine for the CD's. Up to 4 CD's can be directly loaded into this unit.

Due to its compact design, the CD changer can carry out only one operation at a time. For example, you can not load a new disc while playing another at the same time. Each operation happens sequentially

The radio unit provides control over all features of the CD changer with the exception of the CD load and eject functions, which are controlled by buttons located on the front of the CD changer. All features you would expect, such as Disc Up/Down, Track Up/Down, Random and Scan are controlled by the radio, which also displays all relevant CD changer information on the radio display.

The CD changer contains a Load/Eject button and an indicator LED for each of the four disc positions as well as an illuminated disc opening. The individual LED indicates whether a CD is currently loaded in that particular chamber of the CD changer. Pressing the individual Load/Eject button for a particular chamber will eject a disc currently present in that chamber. If the chamber is currently empty, actuating the Load/Eject button will position that chamber to receive and load a new disc in that chamber.

Fig.7 Quarter Glass Integral Antenna:

QUARTER GLASS INTEGRAL ANTENNA - EXPORT
The quarter glass integral antenna element is bonded to the right rear quarter glass and is replaced with the glass assembly only.

The integral antenna receives RF (Radio Frequencies) and sends them to the antenna module for amplification.

RADIO NOISE SUPPRESSION COMPONENTS
Radio noise suppression devices are factory in stalled standard equipment on this vehicle Radio Frequency Interference (RFI) and ElectroMagnetic Interference (EMI) can be produced by any on-board or external source of electromagnetic energy These electromagnetic energy sources can radiate electromagnetic signals through the air, or conduct them through the vehicle electrical system.

When the audio system converts RFI or EMI to an audible acoustic wave form, it is referred to as radio noise. This undesirable radio noise is generally manifested in the form of "buzzing," "hissing, popping, "clicking," "crackling," and/or "whirring" sounds. In most cases, RFI and EMI radio noise can be suppressed using a combination of vehicle and component grounding, filtering and shielding techniques. This vehicle is equipped with factory-installed radio noise suppression devices that were designed to minimize exposure to typical sources of RFI and EMI; thereby minimizing radio noise complaints.

Factory-installed radio noise suppression is accomplished primarily through circuitry or devices that are integral to the factory-installed radios, audio power amplifiers and other on-board electrical components such as generators, wiper motors, blower motors, and fuel pumps that have been found to be potential sources of RFI or EMI.

There are two common strategies that can be used to suppress Radio Frequency Interference (RFI) and ElectroMagnetic Interference (EMI) radio noise. The first suppression strategy involves preventing the production of RFI and EMI electromagnetic signals at their sources. The second suppression strategy involves preventing the reception of RFI and EMI electromagnetic signals by the audio system components.

The use of braided ground straps in key locations is part of the RFI and EMI prevention strategy These ground straps ensure adequate ground paths, particularly for high current components such as many of those found in the starting, charging, ignition, engine control and transmission control systems. An insufficient ground path for any of these high current components may result in radio noise caused by induced voltages created as the high current seeks alternative ground paths through components or circuits intended for use by or in close proximity to the audio system components or circuits.

Preventing the reception of RFI and EMI is accomplished by ensuring that the audio system components are correctly installed in the vehicle. Loose, corroded or improperly soldered wire harness connections, improperly routed wiring and inadequate audio system component grounding can all contribute to the reception of RFI and EMI. A properly grounded antenna body and radio chassis, as well as a shielded antenna coaxial cable with clean and tight connections will each help reduce the potential for reception of RFI and EMI.

Fig.10 Remote Radio Switch Operational View:

REMOTE SWITCHES
A remote radio control switch option is available on some models. Two rocker-type switches are mounted on the back (instrument panel side) of the steering wheel spokes. The switch on the left spoke is the seek switch and has seek up, seek down, and preset station advance functions. The switch on the right spoke is the volume control switch and has volume up, and volume down functions. The switch ON the right spoke also includes a "mode" control that allows the driver to sequentially select AM radio, FM radio, cassette player, CD player or CD changer (if equipped).

These switches are resistor multiplexed units that are hard-wired to the Body Control Module (BCM) through the clockspring. The BCM sends the proper messages on the Programmable Communications Interface (PCI) data bus network to the radio receiver. For diagnosis of the BCM or the PCI data bus, the use of a DRB III scan tool and the proper Diagnostic Procedures manual are recommended. For more information on the operation of the remote radio switch controls, refer to the owner's manual in the vehicle glove box.