1999 GMC Sonoma Owner's Manual - Page 86

yellowblue Leaving Your Vehicle With the Engine Running (Automatic Transmission Only) CAUTION: It can be dangerous to leave your vehicle with the engine running. Your vehicle could move suddenly if the shift lever is not fully in PARK (P) with the parking brake firmly set. And, if you leave the vehicle with the engine running, it could overheat and even catch fire. You or others could be injured. Don't leave your vehicle with the engine running unless you have to. D Move the lever up as far as it will go. 3. Turn the ignition key to LOCK. 4. Remove the key and take it with you. If you can leave your vehicle with the key, your vehicle is in PARK (P). 2-28