2000 GMC Envoy Owner's Manual - Page 76

Ignition Positions Use the key to turn the ignition switch to five different positions. NOTICE: Don't operate accessories in the ACCESSORY position for long periods of time. Prolonged operation of accessories in the ACCESSORY position could drain your battery and prevent you from starting your vehicle. LOCK (B): This position locks your ignition, steering wheel and transmission. It's a theft-deterrent feature. You will only be able to remove your key when the ignition is turned to LOCK. NOTICE: ACCESSORY (A): This position lets you use things like the radio and the windshield wipers when the engine is off. Push in the key and turn it toward you. Your steering wheel will remain locked, just as it was before you inserted the key. If your key seems stuck in LOCK and you can't turn it, be sure you are using the correct key; if so, is it all the way in? If it is, then turn the steering wheel left and right while you turn the key hard. But turn the key only with your hand. Using a tool to force it could break the key or the ignition switch. If none of this works, then your vehicle needs service. 2-14