GM Service Manual Online
For 1990-2009 cars only

All audible warnings are generated by the radio and radio amplifier. All such warnings are provided to the radio via messages on the Class 2 serial data line. The Class 2 messages, which produce the required chimes, are controlled by several modules as follows:

    • The Key in Ignition Chime Class 2 messages are controlled by the Instrument Panel Integration Module (IPM).
    • The Lamps On Chime messages are controlled by the Dash Integration Module (DIM).
    • The Fasten Belts Chime messages are controlled by the instrument cluster (IPC).
    • The Turn Signal On Chime messages are controlled by the IPC.
    • The various warning condition chimes such as Oil Low Pressure Warning Chime Class 2 messages are sent by the IPC. Each of these has an associated DIC message and/or IPC Indicator.