Radio/Stereo: Description and Operation
RADIO SYSTEMThere are three radio systems available that will be on the CCD bus. They are the RBR, RBN and RAZ models. The main reason they are on the bus is because of the radio remote controls in the steering wheel. They can control volume up/down, seek up/down and preset station selections. These systems also communicate with the Body Control Module and will set a specific code if there is a problem with the remote controls.
The RBR will have 4 speakers and the others will have 8 speaker locations (Infinity sound). All of the 4 main quarter speakers have a built in amplifier. The I/P and pillar speakers receive their signals from the quarter speakers. Depending on the manufacture some systems will have a Front/Rear channel system and others will have a Left/Right channel system. If one of the main quarter speaker audio circuits experiences a short, the other speakers on that channel will also shut down until the circuit is repaired. The radio will also set a trouble code, which is assessible with the DRB, indicating which channel is effected.
RADIOS
Available factory-installed radio receivers for this model include:
- AM/FM/Cassette (RAS sales code)
- AM/FM/Cassette/5-band Graphic Equalizer with CD changer control feature (RBN sales code)
- AM/FM/Cassette/CD/3-band Graphic Equalizer (RAZ sales code)
All factory-installed radio receivers are stereo Electronically Tuned Radios (ETR) and include an electronic digital clock function.
All factory-installed radio receivers, except the RAS model, communicate on the Chrysler Collision Detection (CCD) data bus network through a separate two-way wire harness connector. The CCD 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.
In addition, radios connected to the CCD data bus have several audio system functions that can be diagnosed using a DRB scan tool. Refer to the proper Diagnostic Procedures for more information on DRB testing of the audio systems.
The radio can only be serviced by an authorized radio repair station. Refer to the latest Warranty Policies and Procedures for a current listing of authorized radio repair stations.
For more information on radio features, setting procedures, and control functions refer to the owner's manual in the vehicle glove box.
Numerous ground straps are placed throughout the vehicle for interference elimination.
Motor Mount to Frame Rail Ground:
Engine Ground Locations (2.0L):
Engine Ground Locations (2.4L):
Engine Ground Locations (2.4L):
Engine Ground Locations (3.0L):
Engine Ground Locations(3.3/3.8L):
If receiving ignition/engine interference noise on the radio stations, check and clean all engine and body ground connections. Ensure all ground connections are without corrosion.
Tighten properly after cleaning.
REMOTE RADIO SWITCHES
Remote Radio Switch Operational View:
A remote radio control switch option is available on LXI models sold in North America with the AM/FM/ CD/Cassette/3-band Graphic Equalizer (RAZ sales code) radio receiver. 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.
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 Chrysler Collision Detection (CCD) data bus network to the radio receiver. For diagnosis of the BCM or the CCD data bus, the use of a DRB scan tool and the proper Diagnostic Procedures 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.
INTERFERENCE ELIMINATION
Some components used on the vehicles are equipped with a capacitor to suppress radio frequency interference/static.
Capacitors are mounted in various locations internal to the alternator, instrument cluster and windshield wiper motor.
To suppress radio interference, ground straps are used in different areas of the vehicle. These ground circuits should be securely tightened to assure good metal to metal contact. The ground straps conduct very small high frequency electrical signals to ground and require clean surface contact area. The radio ground is supplied from the instrument panel harness and is attached to the rear of the radio. Some engines have other ground straps to eliminate further radio interference:
- Radio chassis to instrument panel structure
- Engine to dash panel
- Engine to chassis
- A/C H-valve to dash panel
Radio resistance type spark plug cables in the high tension circuit of the ignition system complete the interference suppression. Faulty or deteriorated spark plug wires should be replaced.
NAME BRAND SPEAKER RELAY
The Name Brand Speaker Relay is located in the junction block.
To test relay refer to the Audio Diagnostic Test Procedures or use a known good relay.