2001 Cadillac Catera Owner's Manual - Page 115

If you're not in PARK (P) and the Twilight Sentinel system is turned off (and it's dark enough outside), the DRL will remain active and this light on the instrument panel cluster will appear. This is a reminder that headlamps are required. The following conditions will override the DRL: Fog Lamps Use the fog lamps for better vision in foggy or misty conditions. Press this button to turn the fog lamps on and press the button again to turn the lamps off. (The fog lamps only work when the parking lamps or the low-beam headlamps are on and the ignition is on.) D The vehicle's transmission is shifted back into PARK (P) with the ignition in ON or START, D the low-beam headlamps are turned on (using the manual lamp knob), D the wiper-activated headlamps are in use D the flash-to-pass feature is in use, or D the Twilight Sentinel is turned on. (DRL will come back on 20 seconds after wipers have turned off), This light on the instrument panel will come on when the fog lamp button is pressed. As with any vehicle, you should turn on the regular headlamp system when you need it. If you turn on the high-beam headlamps, the fog lamps will turn off. They'll turn back on again when you switch to low-beam headlamps. 2-48