2001 GMC Sierra 1500 Pickup Owner's Manual - Page 89

Your vehicle has one double-sided key for the ignition and all door locks. Door Locks CAUTION: Unlocked doors can be dangerous. D Passengers -- especially children -- can easily open the doors and fall out of a moving vehicle. When a door is locked, the handle won't open it. You increase the chance of being thrown out of the vehicle in a crash if the doors aren't locked. So, wear safety belts properly and lock the doors whenever you drive. D Young children who get into unlocked vehicles may be unable to get out. A child can be overcome by extreme heat and can suffer permanent injuries or even death from heat stroke. Always lock your vehicle whenever you leave it. D Outsiders can easily enter through an unlocked door when you slow down or stop your vehicle. Locking your doors can help prevent this from happening. Your vehicle may also have a key that locks and unlocks only the center floor console (if equipped). If you ever lose your keys, your dealer will be able to assist you with obtaining replacements. 2-6