Alero L4-144 2.4L DOHC VIN T SFI (2000)
Marker Lamp: Description and Operation
Voltage is applied to the turn/headlamp switch at all times. When the turn/headlamp switch is in the PARK or the HEAD position, voltage is applied to
the following components:
^
The park lamps
^
The marker lamps
^
The tail lamps
^
The license lamp
The front marker lamps are grounded through the turn filament of the respective front park/turn lamp. The front marker lamps light as a result.
The automatic lamp control function turns on the park lamps and the headlamps. This action occurs when the ambient light sensor determines that the
exterior lamps should be turned ON based on the amount of available light. When the BCM grounds the park lamp relay, voltage is supplied directly to
the park lamps, bypassing the turn/headlamp switch assembly. When this action occurs, the following conditions exist:
^
The automatic lamp control relay is grounded.
^
The headlamps turn ON. Refer to Headlights/ Daytime Running Lights (DRL) Circuit Description.
The lamps turn OFF when the BCM does not ground the park lamp relay or the automatic lamp control relay. This action is caused by the following
conditions:
^
The available light reaches a predetermined level.
^
The ignition switch is turned to the OFF position.
