System Description

AUDIO
There are four different system combinations available on this model. The available radio options are:
- AM/FM Cassette
- AM/FM Compact Disc with Compact Disc changer controls
- AM/FM Cassette with single Compact Disc Player and Compact Disc changer controls
- AM/FM Cassette with Compact Disc changer controls
- AM/FM Cassette with Compact Disc player, rear seat audio system and Compact Disc changer controls.

The rear seat audio system allows passengers to listen to a different music source, through headphones, other than what is playing through the vehicles speaker system. A remote control is provided for functions such as changing stations, tracks, disc and modes while listening to rear seat audio. The radio must be turned ON to use the rear seat audio system.

All factory installed radio receivers are stereo Electronically Tuned Radios (ETR) and include and electronic digital clock function.

Operating instructions for the factory installed audio systems can be found in the Owner's Manual provided with this vehicle.

Some of the radios are on the PCI Bus system. The PCI Bus inputs into the radio are used for VF dimming, remote steering wheel controls and cabin EQ preference. PCI Bus outputs from the radio are used for the Name Brand Speaker (NBS) relay activation, as well as cabin EQ preference.

The RBB and RBK radios have the capability of containing multiple vehicle unique equalization curves (cabin EQ preferences) within the radio. These curves will reside in the radio's flash memory. The radio is capable of storing up to 20 unique equalization curves. The latent curves can be selected via the Front Control Module transmitting a PCI Bus message to the radio in response to a radio request for equalization message. Upon receipt of a valid equalization select message response, the radio will switch to output the corresponding equalization curve.

All the radios, except the RAS, are capable of displaying faults and allowing certain actuation tests through the use of the DRB III. When attempting to perform PCI Bus diagnostics, the first step is to identify the radio in use in the vehicle.

When trouble shooting output shorts or "output" error messages, the following applies:

On radios without an external amplifier, the term output refers to the path between the radio and the speaker. This type of circuit can be monitored all the way through the speaker connections by the radio assembly. When the radio displays a shorted output DTC with this type of system, the speaker, radio, or wiring could be at fault.

On radios with an external amplifier, the term "output" refers to the circuit between the radio connector and the amplifier. The radio is capable of monitoring only this portion and can tell nothing about the circuit between the amplifier and the speakers. Consequently, a shorted output DTC on this type of system would only refer to this circuit. A faulty speaker could not cause this DTC.