2002 GMC Envoy Owner's Manual - Page 105

Running Your Engine While You're Parked It's better not to park with the engine running. But if you ever have to, here are some things to know. CAUTION: It can be dangerous to get out of your vehicle if the shift lever is not fully in PARK (P) with the parking brake firmly set. Your vehicle can roll. Don't leave your vehicle when the engine is running unless you have to. If you've left the engine running, the vehicle can move suddenly. You or others could be injured. To be sure your vehicle won't move, even when you're on fairly level ground, always set your parking brake and move the shift lever to PARK (P). If you have four-wheel drive, your vehicle will be free to roll -- even if your shift lever is in PARK (P) -- if your transfer case is in NEUTRAL. So be sure the transfer case is in a drive gear -- not in NEUTRAL. See "Four-Wheel Drive (Automatic Transfer Case)" in the Index. Follow the proper steps to be sure your vehicle won't move. See "Shifting Into PARK (P)" in the Index. If you're pulling a trailer, see "Towing a Trailer" in the Index. CAUTION: Idling the engine with the climate control system off could allow dangerous exhaust into your vehicle. See the earlier Caution under "Engine Exhaust." Also, idling in a closed-in place can let deadly carbon monoxide (CO) into your vehicle even if the fan is at the highest setting. One place this can happen is a garage. Exhaust -- with CO -- can come in easily. NEVER park in a garage with the engine running. Another closed-in place can be a blizzard. See "Blizzard" in the Index. 2-36