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: 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 pulling a trailer, see Towing a Trailer for more information.

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 the Vehicle While Parked" in the owner 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 P (Park) or N (Neutral), 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: Idling a vehicle in an enclosed area with poor ventilation is dangerous. Engine exhaust may enter the vehicle. Engine exhaust contains Carbon Monoxide (CO) which cannot be seen or smelled. It can cause unconsciousness and even death. Never run the engine in an enclosed area that has no fresh air ventilation. For more information, see Engine Exhaust.

Caution: It can be dangerous to get out of the vehicle if the automatic transmission shift lever is not fully in P (Park) with the parking brake firmly set. The vehicle can roll. Do not leave the 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 the vehicle will not move, even when you are on fairly level ground, always set the parking brake and move the shift lever to P (Park).

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

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

If pulling a trailer, see Towing a Trailer.