GMC 2009 Sierra - Manual (Page 393)

Changing a Flat Tire
If a tire goes flat, avoid further tire and wheel damage
by driving slowly to a level place. Turn on your vehicle’s
hazard warning flashers. See Hazard Warning Flashers
on page 3-6 for more information.
{ CAUTION:
Changing a tire can be dangerous. The vehicle
can slip off the jack and roll over or fall on you
or other people. You and they could be badly
injured or even killed. Find a level place to
change your tire. To help prevent the vehicle
from moving:
1. Set the parking brake firmly.
2. Put the shift lever in PARK (P).
3. Turn off the engine and do not restart
while the vehicle is raised.
4. Do not allow passengers to remain
in the vehicle.
To be even more certain the vehicle will not
move, you should put blocks at the front and
rear of the tire farthest away from the one being
changed. That would be the tire, on the other
side, at the opposite end of the vehicle.
When your vehicle has a flat tire, use the following
example as a guide to assist you in the placement
of wheel blocks.
The following information tells you how to use the
jack and change a tire.
5-81