2002 GMC Envoy Owner's Manual - Page 286

Hazard Warning Flashers The button for the hazard warning flashers is located on top of the steering column. The hazard warning flashers work no matter what position your key is in, and even if the key isn't in. Press the button all the way down to make your front and rear turn signal lamps flash on and off. To turn off the flashers, press the button again until it clicks and then release it. Your hazard warning flashers let you warn others. They also let police know you have a problem. Your front and rear turn signal lamps will flash on and off. When the hazard warning flashers are on, the turn signals won't work. Other Warning Devices If you carry reflective triangles, you can set one up at the side of the road about 300 feet (100 m) behind your vehicle. 5-2