GMC 2004 Yokon Denali Owner's Manual page 113

Liftgate/Liftglass
CAUTION:
{
It can be dangerous to drive with the liftgate or
liftglass open because carbon monoxide (CO)
gas can come into your vehicle. You can not
see or smell CO. It can cause
unconsciousness and even death. If you must
drive with the liftgate open or if electrical
wiring or other cable connections must pass
through the seal between the body and the
liftgate or liftglass:
•
Make sure all other windows are shut.
•
Turn the fan on your heating or cooling
system to its highest speed and select the
control setting that will force outside air
into your vehicle. See Climate Control
System in the Index.
•
If you have air outlets on or under the
instrument panel, open them all the way.
See Engine Exhaust on page 2-30.
To unlock the liftgate and liftgate glass from the outside
use either the power door locks or the remote keyless
entry system.
The liftgate glass can be opened using the pushbutton
on the liftgate after the doors have been unlocked.
To open the entire liftgate, lift the handle located in the
center of the door.
To lock the liftgate and liftgate glass from the outside
use the remote keyless entry system or the power door
locks.
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