GMC 2007 Yukon XL Owner's Manual page 119

The vehicle cannot be remote started if the key is
in the ignition, the hood is not closed, or if
there is an emission control system malfunction.
Also, the engine will turn off during a remote
vehicle start if the coolant temperature gets too
high or if the oil pressure gets low.
Vehicles that have the remote vehicle start feature
are shipped from the factory with the remote
vehicle start system enabled. The system may be
enabled or disabled through the DIC. See
"REMOTE START" under DIC Vehicle
Customization (With DIC Buttons) on page 264
for additional information.
Remote Start Ready
If your vehicle does not have the remote vehicle
start feature, it may have the remote start
ready feature. This feature allows your dealer to
add the manufacturer's remote vehicle start
feature.
If your vehicle has the remote start ready feature,
your RKE transmitter will have extended range
that will allow you to lock or unlock your vehicle
from approximately 197 feet (60 m) away.
See your dealer if you would like to add the
manufacturer's remote vehicle start feature to your
vehicle.
119