The high beam headlamps are controlled by the BCM through the high beam relay. The relay is supplied battery voltage and is energized when the BCM grounds the low side drive control circuit. The flash to pass switch signal circuit is referenced from battery voltage by the BCM and when the switch is activated the signal circuit is grounded, and the BCM determines the switch is active when the signal circuit voltage is low.

Schematic Reference

Headlights/Daytime Running Lights (DRL) 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

With the headlamps ON, observe the scan tool Flash to Pass Switch parameter while pulling and releasing the flash to pass switch. The parameter should cycle between Active and Inactive.

1. Ignition OFF, disconnect the X2 harness connector at the turn signal/multifunction switch.
2. Test for less than 1 ohm of resistance between the ground circuit terminal D and ground.

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

3. Ignition ON, verify the scan tool Flash to Pass Switch parameter is Inactive.

⇒	If not the specified value, test the signal circuit terminal A 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 A and the ground circuit terminal D. Verify the scan tool Flash to Pass 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 signal/multifunction switch.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.