Low Beam Headlamps
The headlamps may be turned ON in 3 different ways:
- When the turn signal/multifunction switch is placed in the ON position, for normal operation
- When the turn signal/multifunction switch is placed in the AUTO position, for automatic lamp control
- When the turn signal/multifunction switch is placed in the AUTO position, with the windshield wipers ON in daylight conditions, after a 6 second delay
The BCM will also command the low beam headlamps ON during daylight conditions when the following conditions are met:
- Turn signal/multifunction switch in the AUTO position
- Windshield wipers ON
- Vehicle in any gear but PARK
When the BCM commands the low beam headlamps ON, the operator will notice the interior backlighting for the instrument cluster and the various other switches dim to the level of brightness selected by the instrument panel dimmer switch.
The body control module (BCM) monitors three signal circuits from the turn signal/multifunction switch. When the turn signal/multifunction switch is in the AUTO position, all three signal circuits are open. When placed in the AUTO position, the BCM monitors inputs from the ambient light sensor to determine if headlamps are required or if daytime running lamps will be activated based on outside lighting conditions. When the turn signal/multifunction switch is placed in the OFF position, the turn signal/multifunction switch headlamps OFF signal circuit is grounded, indicating to the BCM that the exterior lamps should be turned OFF. With the turn signal/multifunction switch in the PARK position, the turn signal/multifunction switch park lamps ON signal circuit is grounded, indicating that the park lamps have been requested. When the turn signal/multifunction switch is placed in the HEADLAMP position, both the turn signal/multifunction switch park lamps ON signal circuit and the turn signal/multifunction switch headlamps ON signal circuit are grounded. The BCM responds to the inputs by illuminating the park lamps and headlamps. When the low beam headlamps are requested, the BCM applies B+ to both low beam headlamp control circuits illuminating the low beam headlamps.