Volt

Hazard Lamps Malfunction

The hazard flashers may be activated in any power mode. The hazard switch signal circuit is momentarily grounded when the hazard switch is pressed. The body control module (BCM) responds to the hazard switch signal input by supplying battery voltage to all four indicator lamps in an ON and OFF duty cycle. When the hazard switch is activated, the BCM sends a serial data message to the instrument panel cluster requesting both indicator indicators to be cycled ON and OFF.

Schematic Reference

Exterior Lamps Schematics

Connector End View Reference

Component Connector End Views

Description and Operation

Exterior Lighting Systems Description and Operation

Electrical Information Reference

Scan Tool Reference

Control Module References for scan tool information

1. Vehicle in Service Mode, observe the scan tool Hazard Lamps Switch parameter while turning the hazard lamp switch ON and OFF. The parameter should change between Active and Inactive.

⇒	If the parameter does not change between the commanded states, refer to Circuit/System Testing.

2. Observe the right and left indicator lamps while turning the hazard lamps switch ON and OFF. The right and left indicator lamps should flash ON and OFF while the hazard lamps switch is ON and remain OFF when the hazard lamps switch is OFF

⇒	If the indicator lamps do not cycle between the selected states, refer to Indicator Lamps and/or Indicators Malfunction .

1. Vehicle OFF, disconnect the harness connector at the A20 Radio/HVAC Controls.
2. Vehicle OFF, scan tool disconnected, all doors closed, all accessories OFF, and wait 2 minutes. Test for less than 5 Ω between the ground circuit terminal 17 and ground.

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

3. Vehicle in Service Mode, verify the scan tool Hazard Lamps Switch parameter is Inactive.

⇒	If not the specified value, test the signal circuit terminal 16 for a short to ground. If the circuit tests normal, replace the K9 Body Control Module.

4. Install a 3 A fused jumper wire between the signal circuit terminal 16 and the ground circuit terminal 17. Verify the scan tool Hazard Lamps 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 K9 Body Control Module.

5. If all circuits test normal, replace the A20 Radio/HVAC Controls.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.