GMC 2011 Yukon Denali Owner's Manual page 346

9-68 Driving and Operating
When replacing the fuel cap, insert
the tether in its hole before
tightening the cap. Turn the fuel cap
clockwise until it clicks. It will require
more effort to turn the fuel cap on
the last turn as you tighten it. Make
sure the cap is fully installed. The
diagnostic system can determine if
the fuel cap has been left off or
improperly installed. This would
allow fuel to evaporate into the
atmosphere. See
If the vehicle has a Driver
Information Center (DIC), the
TIGHTEN GAS CAP message
displays if the fuel cap is not
properly installed.
If a fire starts while you are
refueling, do not remove the
nozzle. Shut off the flow of fuel by
shutting off the pump or by
.
notifying the station attendant.
Leave the area immediately.
WARNING
If a new fuel cap is
needed, be sure to get the right
type of cap from your dealer. The
wrong type fuel cap might not fit
properly, might cause the
malfunction indicator lamp to
light, and could damage the fuel
tank and emissions system. See
.