GM Service Manual Online
For 1990-2009 cars only

Diagnostic Instructions

    • Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure.
    • Review Strategy Based Diagnosis for an overview of the diagnostic approach.
    •  Diagnostic Procedure Instructions provides an overview of each diagnostic category.

Circuit/System Description

The radio generates the audible warning through the left front speaker. The radio receives audible warning requests via class 2 serial data from the body control module (BCM).

Reference Information

Schematic Reference

    •  Instrument Cluster Schematics
    •  Body Control System Schematics
    •  Radio/Navigation System Schematics

Connector End View Reference

    •  Displays and Gages Connector End Views
    •  Data Communication Connector End Views
    •  Entertainment/Communication Connector End Views

Electrical Information Reference

    •  Circuit Testing
    •  Connector Repairs
    •  Testing for Intermittent Conditions and Poor Connections
    •  Wiring Repairs

Scan Tool Reference

Scan Tool Data List

Circuit/System Testing

  1. Ignition ON, headlamp switch OFF, verify the scan tool Headlamp Off Switch parameter is Inactive.
  2. If not Inactive, test the headlamps off signal circuit for an open or short to voltage. If the circuit tests normal, replace the headlamp switch.
  3. Ignition ON, park lamp switch OFF, verify the scan tool Park Lamp Switch parameter is Off.
  4. If not Off, test the park lamp switch signal circuit for an open or short to voltage. If the circuit tests normal, replace the headlamp switch.
  5. Ignition OFF, key out of the ignition, verify the scan tool Key In Ignition Status parameter is Inactive.
  6. If not Inactive, test the key in ignition switch signal circuit for a short to ground. If the circuit tests normal, replace the ignition switch.
  7. Ignition ON, doors closed, verify the scan tool the LF and RF Door Ajar Switch parameters are Door Closed.
  8. If not Door Closed, go to Courtesy Lamps Always On .
  9. Ignition ON, doors closed, verify the scan tool Left and Right Rear Door Ajar Switch parameters are Closed.
  10. If not Closed, go to Courtesy Lamps Always On .
  11. If all circuits test normal, replace the BCM.

Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

    •  Ignition and Start Switch Replacement
    •  Control Module References for BCM replacement, setup, and programming