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Home >> Saturn Truck >> 2002 >> VUE V6-3.0L VIN B >> Repair and Diagnosis >> Accessories and Optional Equipment >> Radio, Stereo, and Compact Disc >> Description and Operation >> Part 1

Part 1





Radio/Audio System Description and Operation

Contents

- RPO Options
- Features
- Circuit Description
- Component Description
- Customer Tips
- On Board Diagnostics
- Theft Deterrent Feature

RPO Options

The entertainment system on this vehicle is configured with either a base or uplevel audio system. Both the base and uplevel audio systems contain a radio, antenna, and speakers.

The following shows the Entertainment RPO's that are available for this vehicle:

(UM7) AM/FM Radio






(U1C) AM/FM CD Radio






(UP0) AM/FM Cassette/CD Radio






(UR9) AM/FM Cassette/6 Disc CD Radio






- (UQ4) Base Four Speaker
- (UW6) Uplevel Six Speaker
- (WBM) Premium Audio
(Includes amplifier and subwoofer for VUE; or amplifier and subwoofer rear speakers for ION)

Radio Features










Cassette Player Features






CD Player Features










Circuit Operation

Radio Power: The main radio power is supplied by the 10A RADIO (BATT1) fuse in the Body Control Module (BCM). Radio switch-on power, 12 volts in ACC, RUN or RAP, is supplied by the 10A RADIO (ACC.) in the BCM.

Radio Grounds: The main radio ground provides a ground for the radio circuits. An additional braided ground strap provides a shielding radio case ground to reduce EMI noise. Both grounds are connected together inside the radio.

Radio Speaker Outputs: At zero volume, the plus (+) and minus (-) speaker outputs are both approximately 5-6 volts, measured to vehicle ground. If a plus or minus for any speaker output is shorted to ground or voltage, the radio circuitry will turn off all four speaker outputs for component protection. Above zero volume, the plus and minus change to create a voltage difference between each other, to drive the voice coil of the speaker.

Radio Park Lamp Input: The radio park lamp input allows the radio to sense when the vehicle parking lamps are on. When the parking lamps are on, this circuit goes to battery voltage, and the radio display back-lighting switches from full bright to the brightness level determined by the I/P illumination input.

Radio I/P Illumination Input: A pulse width modulated (PWM) voltage for instrument panel (I/P) illumination is provided to the radio I/P illumination input. The Radio uses this input to directly illuminate the radio buttons and adjust the radio display back-lighting when the park lamp input is on.

Amplifier Power: The main amplifier power is provided by the 20A PREM AUDIO fuse in the Under-Hood Fuse Block (UHFB).

Amplifier Radio Speaker Inputs (WBM only): The radio speaker outputs, at a reduced output level for amplified systems, are the amplifier inputs. The amplifier boosts these inputs and outputs them to the vehicle speakers. Speaker plus and minus circuits from the radio change to create a voltage difference between each other. If one speaker plus or minus is open between the radio and the amplifier, the input to the amplifier is approximately half because only one of the circuits is changing. The speaker for that channel then operates at approximately only half the normal volume.

Amplifier Speaker Outputs (WBM only): At zero volume, the plus (+) and minus (-) speaker outputs are both approximately 5-6 volts, measured to vehicle ground. If a plus or minus for any speaker output is shorted to ground or voltage, the amplifier circuitry will turn OFF either the front outputs or rear outputs for component protection. Above zero volume, the plus and minus change to create a voltage difference between each other, to drive the voice coil of the speaker.

Amplifier Present (WBM only): The amplifier grounds this circuit so the radio can detect an amplified speaker system. When this circuit is grounded, the radio sets the internal equalization to match the amplified speaker system and lowers the radio speaker output level for amplifier input use. If an amplifier is being sensed, the radio OBD equalization setting function will show EQ:00.

Amplifier Radio-On (WBM only): When the radio is ON, this circuit is pulled to 12 volts by the radio. The amplifier switches ON when this circuit is 12 volts and switches OFF when this signal is 0 volts.

Remote Radio Audio Signal Inputs (UE1 only): Audio output from the OnStar communications module connects to the remote audio signal inputs of the radio. When the cellular telephone mute signal goes to 0 volts, the radio over-rides any other audio signal and uses these inputs as the source for output to the speakers.

Cellular Telephone Mute (UE1 only): The OnStar communications module uses the cellular telephone mute signal circuit to over-ride the radio for OnStar communication. When cellular telephone mute is not active, this circuit is held at 2 volts by the radio. When the cellular telephone mute signal is pulled to ground, the radio over-rides any other audio signal and uses the remote audio signals as the source for output to the speakers. If the radio was OFF when this circuit is pulled low, the radio will turn ON. Additionally, the radio fades the speakers to full front, adjusts the volume to an initial audible level, and sets an AutoTone designed for optimal use with OnStar. When the mute signal is no longer pulled to ground, the radio returns to the mode it was in previously.

Component Description

Antenna System

The antenna system receives broadcast AM or FM stereo signals from free space and sends the signals to the radio receiver for processing via a coaxial antenna cable. Good antenna grounding is important for good radio reception.

The antenna base and mast should be installed to the torque specifications provided in the Antenna -- Removal and Installation procedures.

The antenna mast is a single � wave design located at the right front fender.

Ground Strap

The braided ground strap, which is connected between the radio case and the instrument panel fuse block (IPFB), is provided to improve reception and deter noise from entering the audio system.

Radio

The operator interfaces with the radio system through the radio display and controls. Through these controls the operator is able to control system power, volume, fade, balance, bass, and treble equalizations. Control on the integrated tape, single CD or 6 disc CD playback systems is also available when equipped with those options. An LCD (liquid crystal display) provides system feedback to the operator.

The radio processes the AM and FM signals from the antenna system of the information from the cassette tape or CD media sections, amplifies that information and sends the output to the speaker system.

The radio is located in the instrument panel center stack area and is fastened to the instrument panel by two fasteners. Guide pins are provided to aid in aligning the radio. Electrical connections to the radio are a 24-way connector from the I/P harness, antenna lead connector and braided ground strap. An additional 12-way harness connector is present on OnStar equipped vehicles. Additional service length is provided in the radio harnesses to allow connection prior to radio installation.

Clock time is displayed continuously on all radio models even then the ignition is OFF. Temporary backlighting is provided if the RCL button is pressed with the ignition OFF. Backlighting is ON whenever the ignition is ON and dims with the instrument panel illumination when the vehicle park lamps are ON.

Radio amplifier outputs to the speakers are protected from damage should speaker leads become shorted to ground or shorted to vehicle power. The radio will sense these conditions and shut down the amplifier outputs in a non-destructive manner. After the short condition is removed, the radio will return to normal operation.

Speakers

The speaker system consists of four 6 inch high sensitivity speakers (HSS). The optional speaker system (RPO UW6) includes an additional tweeter speaker mounted in the front driver and passenger door mirror trim panel. The premium audio package (RPO WBM) uses the UW6 speakers in the front doors and replaces the rear HSS speakers with subwoofer speakers on the ION. The VUE premium audio package (RPO WBM) adds a subwoofer.

OnStar

OnStar equipped (RPO UE1) vehicles use the radio amplifier and speaker system for voice communication from the OnStar operator to the vehicle. Voice communication from the vehicle to the OnStar operator is through the OnStar microphone and module, which is not a part of the radio system.

When OnStar begins operation, the radio volume is set to a preset level, autotone preset for OnStar becomes active and the fade control is adjusted to the full front speakers. The radio volume control can then be used to adjust the volume to a desired level.

The radio system and OnStar system are connected through the 12-way connector at the back of the radio. Left and right channel OnStar audio, mute control of radio functions by OnStar, and the audio signal ground are the circuits provided in the 12-way connector.

Disconnecting the 12-way connector from the radio will isolate the radio system from the OnStar system. Voice communication from the vehicle to the OnStar operator could be possible under this condition. However, the vehicle occupant will not be able to hear the OnStar operator.

Amplifier

Vehicles equipped with Premium Audio (RPO WBM) include an amplifier. The amplifier has low level inputs from the radio for the four speaker channels and amplifies the sound. The amplifier receives a radio on signal from the radio. This signal is delayed momentarily at initial key on to prevent any speaker pops during startup.

Customer Tips

Radio Reception - FM

Select Stations Within Range: The best FM fidelity will be obtained from stations within a 16-64 km (10-40 mile) range. Noise or distortion may become apparent when attempting to receive stations at distances greater than this range.

Suggestion: Reduce treble response when attempting to receive fringe stations.

Tall Structures: Tall buildings or hills may cause degrading or loss of signal. FM stations tend to travel "line of sight." Buildings or hills can interrupt the FM signal.

Suggestion: Reduce treble response.

Interference from another station: Although receiver circuits are among the most advanced type available, there are instances where a radio station can be interfered with by another station.

Suggestion: Select another station or switch to a cassette or CD.

Radio Reception - AM

Static Interference During Weather Disturbances:AM reception is sensitive to storm disturbances such as lightning.

Suggestion: Reduce treble response or select an FM station for weather related information.

Care of Compact Discs

- Handle compact discs (CDs) carefully. Touch only the outer edges of the CD or the edge of the hole in the center of the CD. Never touch the glossy side of the CD. Fingerprints and scratches will interrupt the "reading" of the information on the disc.
- Store CDs in their protective cases. Store CDs away from sunlight, dirt, dust, and debris.
- Do not attach a label or tape to a CD.
- Always check for scratches and signs of wear on both sides of the CD.
- Never place any marks on the CD with a marker.
- If a CD becomes contaminated, clean it with a clean, damp, soft, lint-free cloth and mild detergent. Wipe the CD in a straight line from the center hole outward. Do not use cleaning solutions which may damage the CD, such as chemically treated cleaning cloths, benzene, or paint thinners.

Compact Discs Not Appropriate to Use

These CD players were designed to be compatible with round digital audio CDs with the "Compact Disc Digital Audio" label. Other CDs may be incompatible, causing a no-play condition, excessive skips, "ERR" shown on the radio display or a jam in the loading mechanism. Some incompatible CD types are:

- Special-shaped CDs (any that are not round)
- Re-Writeable CDs (CD-RW type are incompatible)
- Recordable CDs (CD-R type are incompatible)
- Library CDs (with thick bar code labels)
- CD with User-applied labels
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