GMC Yukon Denalid Owner's Manual page 427

CAUTION:
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If you spill fuel and then something ignites
it, you could be badly burned. Fuel can
spray out on you if you open the fuel cap
too quickly. This spray can happen if your
tank is nearly full, and is more likely in hot
weather. Open the fuel cap slowly and wait
for any hiss noise to stop. Then unscrew
the cap all the way.
Be careful not to spill fuel. Do not top off or overfill
the tank and wait a few seconds after you have
finished pumping before removing the nozzle.
Clean fuel from painted surfaces as soon as
possible. See Washing Your Vehicle on page 530.
When replacing the fuel cap, turn it clockwise until
it clicks. 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 Malfunction Indicator Lamp on page 237.
If your vehicle has a Driver Information Center
(DIC), the TIGHTEN GAS CAP message will be
displayed if the fuel cap is not properly installed.
CAUTION:
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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.
Notice: If you need a new fuel cap, be sure to
get the right type. Your dealer can get one
for you. If you get the wrong type, it may not
fit properly. This may cause your malfunction
indicator lamp to light and may damage
your fuel tank and emissions system. See
Malfunction Indicator Lamp on page 237.
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