Hazard Lamps Inoperative

HAZARD LAMPS INOPERATIVE




DIAGNOSTIC FAULT INFORMATION

IMPORTANT: Always perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure. Testing and Inspection

CIRCUIT/SYSTEM DESCRIPTION
The hazard flashers may be activated in any power mode. The hazard switch is permanently grounded through G201. When the hazard switch is placed in the ON position, ground is applied through the hazard switch signal circuit to the body control module (BCM). The BCM supplies battery voltage to all four turn signal lamps in an ON and OFF duty cycle. When the hazard switch is placed in the ON position, the instrument panel cluster (IPC) receives a signal from the BCM via GMLAN requesting both turn signal indicators to be cycled ON and OFF.

CIRCUIT/SYSTEM TESTING
1. Ignition OFF, disconnect the hazard switch.
2. Install a 3-amp fused jumper between the hazard switch signal circuit and ground. The hazard lamps should illuminate.
- If the hazard lamps do not illuminate, repair the hazard switch signal circuit for an open/high resistance. If the circuit tests normal, replace the BCM.
3. Verify that a test lamp illuminates between the hazard switch signal circuit and the hazard switch ground circuit.
- If the test lamp does not illuminate, repair the hazard switch ground circuit for an open/high resistance.
4. If all circuits test normal, test or replace the hazard switch.

REPAIR INSTRUCTIONS

IMPORTANT: Always perform the Diagnostic Repair Verification after completing the diagnostic procedure. Verification Tests

- Hazard Warning Switch Replacement
- Control Module References for BCM replacement, setup, and programming