Buick 2003 Rendezvous Owner's Manual page 319

To remove the fuel cap, turn it slowly to the left
(counterclockwise). The fuel cap has spring in it; if you
let go of the cap too soon, it will spring back to
the right.
If you get fuel on yourself 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. Clean fuel from painted
surfaces as soon as possible. See Cleaning the Outside
of Your Vehicle on page 5-90.
When you put the fuel cap back on, turn it to the right
(clockwise) until you hear a clicking sound. Make
sure you fully install the cap. 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 3-42.
The malfunction indicator lamp (SERVICE ENGINE
SOON or CHECK ENGINE light) will come on if the fuel
cap is not properly installed.
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" in the Index.
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