2001 GMC Sierra 1500 Pickup Owner's Manual - Page 298

Parking on Hills CAUTION: You really should not park your vehicle, with a trailer attached, on a hill. If something goes wrong, your rig could start to move. People can be injured, and both your vehicle and the trailer can be damaged. But if you ever have to park your rig on a hill, here's how to do it: 1. Apply your regular brakes, but don't shift into PARK (P) yet for an automatic transmission, or into gear for a manual transmission. 2. Have someone place chocks under the trailer wheels. 3. When the wheel chocks are in place, release the regular brakes until the chocks absorb the load. 4. Reapply the regular brakes. Then apply your parking brake and shift into PARK (P) for an automatic transmission, or REVERSE (R) for a manual transmission. 5. If you have a four-wheel-drive vehicle, be sure the transfer case is in a drive gear and not in NEUTRAL (N). 6. Release the regular brakes. 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. If you have 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, use the steps that follow. Always put the shift lever fully in PARK (P) with the parking brake firmly set. If the transfer case on four-wheel drive vehicles is in NEUTRAL, your vehicle will be free to roll, even if your shift lever is in PARK (P). So, be sure the transfer case is in a drive gear -- not in NEUTRAL. 4-76