2004 Hummer H2 Owner's Manual - Page 149

Daytime Running Lamps The DRL system will come on when the following conditions are met: The ignition is on, the exterior lamps control is in AUTO, the transmission is not in PARK (P), and the light sensor determines it is daytime. When the DRL are on, only your DRL lamps will be on. The taillamps, sidemarker and other lamps won't be on. The instrument panel won't be lit up either. When it begins to get dark, the automatic headlamp system will switch from DRL to the headlamps. As with any vehicle, you should turn on the regular headlamp system when you need it. Daytime Running Lamps (DRL) can make it easier for others to see the front of your vehicle during the day. DRL can be helpful in many different driving conditions, but they can be especially helpful in the short periods after dawn and before sunset. Fully functional daytime running lamps are required on all vehicles first sold in Canada. 3-15