GM Service Manual Online
For 1990-2009 cars only

It is better not to park with the engine running. But if you ever have to, here are some things to know.

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 climate control 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.

Also see "If You Are Caught in a Blizzard" under Winter Driving .

Caution: If your vehicle has four-wheel drive, it will be free to roll -- even if the shift lever is in PARK (P) -- if the transfer case is in NEUTRAL. So be sure the transfer case is in a drive gear -- not in NEUTRAL. See Four-Wheel Drive .

Follow the proper steps to be sure your vehicle will not move. See Shifting Into Park .

If you are pulling a trailer, see Towing a Trailer .