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.

Diagnostic Fault Information

Circuit

Short to Ground

High Resistance

Open

Short to Voltage

Signal Performance

B+ Voltage Reference

1

B3794 08, B3794 6

1

1

B3794 08, B3794 61

Cruise Control Switch Signal

1

B3794 08, B3794 6

1

B3794 08

B3794 08, B3794 61

Cruise Control Indicator Low Reference

--

2

2

2

--

1. Cruise Control Malfunction

2. Cruise Control Switch Indicator Malfunction

Circuit/System Description

The cruise control switch contains an LED that illuminates to indicate the cruise control system has been switched ON. Voltage is applied through the ON/OFF switch to the LED when the switch is pressed. The body control module (BCM) provides the ground path for the LED through a dedicated LED control circuit. Pressing the switch again opens the switch and the lamp turns OFF.

Reference Information

Schematic Reference

Cruise Control Schematics

Connector End View Reference

Component Connector End Views

Description and Operation

Cruise Control Description and Operation

Electrical Information Reference

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

Scan Tool Reference

Control Module References for scan tool information

Circuit/System Verification

Ignition ON, observe the cruise control indicator while applying the cruise on/off switch. The indicator should turn on and off accordingly with the applied switch.

Circuit/System Testing

Important: Refer to DTC B3794 before performing this diagnostic, if this code is set as current or history.

  1. Ignition OFF, disconnect the harness connector at the steering wheel control switch-left.
  2. Ignition ON, verify that a test lamp illuminates between the low reference circuit terminal 9 and B+.
  3. If the test lamp does not illuminate, test the low reference circuit for a short to voltage or an open/high resistance. If the circuit tests normal, replace the BCM.
  4. If all circuits test normal, test or replace the steering wheel controls switch-left

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