GM Service Manual Online
For 1990-2009 cars only

The audible warnings alert the driver of a system concern or a critical vehicle condition. The audio amplifier generates the audible warnings through the left front speaker. The audio amplifier receives audible warning requests via the serial data circuit. If the audio amplifier receives multiple audible warning requests, the warning with the highest priority sounds first. The following lists the audible warning priority and the pulse rate:

  1. Fast rate chime--200 pulses per minute
  2. Medium rate chime--150 pulses per minute
  3. Slow rate chime--50 pulses per minute
  4. Single chime

Fasten Safety Belt Warning

The audio amplifier activates the fasten safety belt audible warning as requested by the body control module (BCM). The BCM sends a serial data message to the audio amplifier indicating the chime frequency and duration of 8 seconds. The fasten safety belt warning sounds and the fasten safety belt indicator illuminates when the following occurs:

    • The ignition switch transitions to ON.
    • The inflatable restraint sensing and diagnostic module (SDM) detects that the driver's seat belt is not buckled and the signal is low. The SDM sends a serial data message to the BCM indicating the seat belt status. The instrument panel cluster (IPC) receives a serial data message from the BCM indicating the driver seat belt status.

If the seat belt is buckled when the ignition is turned ON, the chime does not sound. If the seat belt is buckled while the chime is sounding, the chime stops. If the seat belt is unbuckled after the initial transition to ON, the chime does not sound.

Lights On Warning

The audio amplifier activates the lights on warning as requested by the body control module (BCM). The BCM sends a serial data message to the audio amplifier indicating the chime frequency of a fast rate and at a continuous duration. The lights on warning sounds when the following occurs:

    • The ignition is OFF.
    • The BCM determines that the driver door is open and the signal circuit is low.
    • The BCM determines that the headlamp switch is in the park or head position.

Brake Warning

The audio amplifier activates the brake audible warning as requested by the instrument panel cluster (IPC). The IPC sends a serial data message to the audio amplifier indicating the chime frequency of a fast rate and at a continuous duration. The brake warning sounds and the BRAKE indicator illuminates when the following occurs:

    • The ignition is ON.
    • The vehicle speed is greater than 8 km/h (4.9 mph). The IPC receives a serial data message from the engine control module (ECM) indicating the vehicle speed.
    • The IPC determines that the park brake is engaged and the signal circuit is low.
    • The brake fluid is low.
    • The dynamic rear proportioning (DRP) failed

Key-In-Ignition Warning

The audio amplifier activates the key-in-ignition audible warning as requested by the body control module (BCM). The BCM sends a serial data message to the radio indicating the chime frequency of a medium rate and continuous duration. The key-in-ignition warning sounds when the following occurs:

    • The ignition switch is OFF.
    • The BCM determines that the driver door is open and the signal circuit is low. The instrument panel cluster (IPC) receives a serial data message from the BCM indicating the door ajar status
    • The BCM determines that the key-in-ignition switch is open and the signal circuit is high. The IPC receives a serial data message from the BCM indicating the key-in-ignition status.

Door Ajar Warning

The audio amplifier activates the door ajar audible warning as requested by the body control module (BCM). The BCM sends a serial data message to the radio indicating the chime frequency of a medium rate and continuous duration. The door ajar warning sounds and the door ajar indicator illuminates when the following occurs:

    • The BCM determines that the driver door is open and the signal circuit is low. The instrument panel cluster (IPC) also receives a serial data message from the BCM requesting illumination of the door ajar indicator.
    • The vehicle is not in PARK. The BCM receives a serial data message from the ECM or BCM indicating the gear position.

Additional Warnings

The following warnings have an associated instrument panel cluster (IPC) indicator:

    • Hot coolant temperature--The audio amplifier activates the audible warning as requested by the BCM or ECM/PCM. The BCM sends a serial data message to the audio amplifier indicating the chime frequency of a medium rate and at a continuous duration.
    • Low fuel--The audio amplifier activates the audible warning as requested by the BCM. The BCM sends a serial data message to the audio amplifier indicating the chime frequency of a medium rate and at a continuous duration.
    • Low engine oil pressure--The audio amplifier activates the audible warning as requested by the IPC. The BCM sends a serial data message to the audio amplifier indicating the chime frequency of a medium rate and at a continuous duration. The low engine oil pressure indicator should be ON in the IPC.

Refer to Indicator/Warning Message Description and Operation.