GM Service Manual Online
For 1990-2009 cars only

Parking the Vehicle Manual Transmission

Before you get out of your vehicle, move the shift lever into REVERSE (R) and firmly apply the parking brake. Once the shift lever has been placed into REVERSE (R) with the clutch pedal pressed in, you can turn the ignition off and release the clutch. If you attempt to exit the vehicle without being in REVERSE (R), the Driver Information Center (DIC) will display SHIFT TO REVERSE and a chime will sound.

Notice: If you do not put a manual transmission in REVERSE (R) before exiting your vehicle, your vehicle will not be secured, the battery will drain and could be damaged. Always put a manual transmission in REVERSE (R) before shutting off the engine and exiting the vehicle.