Headlamps Flash to Pass Inoperative

HEADLAMPS FLASH TO PASS INOPERATIVE

DIAGNOSTIC FAULT INFORMATION





Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure Initial Inspection and Diagnostic Overview.

CIRCUIT/SYSTEM DESCRIPTION
The flash to pass of the headlamp switch supplies a ground to the high beam headlamp circuit when applied. With the ground that is supplied by the flash to pass switch the high beam headlamps will stay ON as long as the switch is toggled.

DIAGNOSTIC AIDS
An open/high resistance in the headlamp switch can cause the flash to pass inoperative.

CIRCUIT/SYSTEM VERIFICATION
Ignition ON, command the flash to pass ON and OFF with the headlamp switch. Observe the high beam headlamps. The headlamp high beams should turn ON and OFF with each commanded.

CIRCUIT/SYSTEM TESTING
1. Ignition OFF, disconnect the harness connector at the headlamp switch.
2. Ignition OFF, test for less than 1 ohm of resistance between the ground circuit and ground.
- If greater than 1 ohm, test the ground circuit for an open/high resistance.
3. Verify the headlamps are OFF.
- If the headlamps are not OFF, test the signal circuit for a short to ground. If the circuit tests normal, replace the BCM.
4. Install a 3-amp fused jumper wire between the signal circuit and ground. Verify the headlamps are ON.
- If the headlamps are not ON, test the signal circuit of the headlamp switch for a short to voltage or an open/high resistance. If circuit tests normal, replace the BCM.
5. If all circuits test normal, test or replace the headlamp switch.

COMPONENT TESTING
1. Ignition OFF, disconnect the harness connector at the headlamp switch.
2. Test for infinite resistance between the signal terminal and the voltage supply terminal with the switch in the open position.
- If less than infinite resistance, replace the headlamp switch.
3. Test for less than 1.5 ohms between the signal terminal and the high and low voltage supply terminals with the switch in the closed position.
- If greater than 1.5 ohms, replace the headlamp switch.

REPAIR INSTRUCTIONS
Perform the Diagnostic Repair Verification after completing the diagnostic procedure.
- Instrument Panel Dimmer Switch Replacement
- Turn Signal Multifunction Switch Replacement Verification Tests