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 activated, the instrument panel cluster (IPC) hazard flasher signal circuit is grounded and the IPC request both turn signal indicators to be cycled ON and OFF. For more detailed information concerning hazard lamp operation refer to Exterior Lighting Systems Description and Operation .

Schematic Reference

Exterior Lights Schematics

Connector End View Reference

Lighting Systems Connector End Views

Electrical Information Reference

Scan Tool Reference

Hazard Lamps Malfunction

1. Ignition OFF, disconnect the harness connector at the hazard switch.
2. Test for less than 1 ohm of resistance between the ground circuit terminal 2 and ground.

⇒	If greater than the specified range, test the ground circuit for an open/high resistance.

3. Ignition ON, verify the scan tool Hazard Lamp Switch parameter is INACTIVE.

⇒	If not the specified value, test the signal circuit terminal 1 for a short to ground. If the circuit tests normal, replace the BCM.

4. Install a 3A fused jumper wire between the signal circuit terminal 1 and ground. Verify the scan tool hazard lamp switch parameter is ACTIVE.

⇒	If not the specified value, test the signal circuit for a short to voltage or an open/high resistance. If the circuit tests normal, replace the BCM.

5. If all circuits test normal, test or replace the hazard switch.

Hazard Lamp Indicators Malfunction

1. Ignition OFF, disconnect the harness connector at the hazard switch.
2. Test for less than 1 ohm of resistance between the ground circuit terminal 2 and ground.

⇒	If greater than the specified range, test the ground circuit for an open/high resistance.

3. Ignition ON, verify that a test lamp illuminates between the signal circuit terminal 4 and ground.

⇒	If the test lamp does not illuminate, test the signal circuit for a short to ground or an open/high resistance.

4. Install a 3A fused jumper wire between the signal circuit terminal 4 and ground. Verify the hazard lamp indicators are ACTIVE.

⇒	If not the specified value, test the signal circuit for a short to voltage. If the circuit tests normal, replace the IPC.

5. If all circuits test normal, test or replace the hazard switch.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.