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 body control module (BCM) monitors the cruise control indicator switch. When the cruise on/off switch is pressed ON, the cruise control switch is closed and the signal circuit is low. When the cruise on/off switch is pressed OFF, the cruise control switch is open and the signal circuit is high.

Reference Information

Schematic Reference

    •  Cruise Control Schematics
    •  Body Control System Schematics

Connector End View Reference

    •  Secondary/Configurable Control Connector End Views
    •  Data 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 OFF, disconnect the cruise control switch assembly.
  2. Connect a fused jumper between the voltage signal circuit and the low reference circuit.
  3. Ignition ON, observe the Cruise On/Off Switch parameter.
  4. If the Cruise On/Off Switch parameter displays ON, replace the cruise control switch assembly.
    If the Cruise On/Off Switch parameter displays Off, test the voltage signal circuit and the low reference circuit for an open, or for a high resistance.
  5. If all circuits test normal, replace the BCM.

Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

    •  Steering Wheel Control Switch Assembly Replacement
    •  Control Module References for BCM replacement, setup, and programming.