For 1990-2009 cars

The lever on the left side of the steering column operates the exterior lamps.

The exterior lamp switch has the following four positions:

& (Headlamps): This position turns on the headlamps, parking lamps, and taillamps.
(Parking Lamps): This position turns on the parking lamps and taillamps only.
AUTO (Automatic Headlamp System): This position automatically turns on the Daytime Running Lamps (DRL) during daytime, and the headlamps, parking lamps, and taillamps at night.
(Off/On): This position is an Off/On switch for the Automatic Headlamp System. In Canada, this applies to vehicles with an automatic transmission set to PARK (P) and manual transmission vehicles with the parking brake engaged.

When operating in AUTO, a brief turn of the switch to off/on will turn off the Automatic Headlamp System. An AUTO LIGHTS OFF message will display on the Driver Information Center (DIC) and a chime will sound. Turning the switch to off/on again will turn the Automatic Headlamp System back on. An AUTO LIGHTS ON message will display on the Driver Information Center (DIC).

The Automatic Headlamp System is always turned on at the beginning of an ignition cycle for vehicles with manual transmission. When the parking brake is engaged, the automatic headlamps will turn off.

For vehicles with an automatic transmission, when the shift lever is shifted out of PARK (P), the Automatic Headlamp System will turn on. Shifting the lever back to PARK (P) will turn off the automatic headlamp system.