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: 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. Do not leave your vehicle when the engine is running unless you have to. If you have left the engine running, the vehicle can move suddenly. You or others could be injured. To be sure your vehicle will not move, even when you are on fairly level ground, always set the parking brake and move the shift lever to PARK (P).

Caution: Four-wheel drive vehicles with the transfer case in NEUTRAL will allow the vehicle to roll, even if the shift lever is in PARK (P). So, be sure the transfer case is in a drive gear -- not in NEUTRAL. Always set the parking brake.

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 .

Tahoe Police Package and Special Service Package

While parked with the engine idling for an extended period, turn off the following factory equipment if emergency lighting and communication equipment are operating:

    • Air Conditioner
    • Fan
    • Rear Window Defogger
    • Factory Audio System

See "Running Your Engine While You're Parked" in your owner's manual Index.

Engine Idle Speed - Alternator Output (Tahoe Police Package and Special Service Package)

Normal idle speed for the engine is set for 600 rpm. To increase alternator output while the transmission remains in PARK (P) or NEUTRAL (N), and the electrical load on the alternator is large enough, the engine idle speed can rise to as high as 800 to 1000 rpm.

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

Caution: Exiting the vehicle, without first shifting into P (Park), may cause the vehicle to move, and you or others can be seriously injured. Because the vehicle has the Automatic Engine Start/Stop feature, the vehicle’s engine might seem to be shut off when you come to a complete stop. However, once the brake pedal is released, the vehicle can move. The vehicle’s engine can also restart at any time.

Shift to P (Park) and turn the ignition to LOCK/OFF, before exiting the vehicle.

Follow the proper steps to be sure the vehicle will not move. See "Shifting Into Park" in the owner manual for more information.

If you are pulling a trailer, see Towing a Trailer for more information.