Fuel System Messages
FUEL LEVEL LOW
This message displays and a chime sounds if the fuel level is low. Refuel as soon as possible. See Fuel Gauge on page 5‑13 and Fuel on page 9‑40 for more information.
TIGHTEN GAS CAP
This message may display along with the check engine light on the instrument panel cluster if the vehicle's fuel cap is not tightened properly. See Malfunction Indicator Lamp on page 5‑18. Reinstall the fuel cap fully. See Filling the Tank on page 9‑42. The diagnostic system can determine if the fuel cap has been left off or improperly installed. A loose or missing fuel cap allows fuel to evaporate into the atmosphere. A few driving trips with the cap properly installed should turn this light and message off.
See also:
Compass
The vehicle may have a compass display on the Driver Information Center (DIC).
The compass receives its heading and other information from the Global Positioning
System (GPS) antenna, StabiliTrak, ...
Online Owner Center
Manage your vehicle (U.S.) at gmc.com. Click on “Owners,” then “Manage My GMC/Owners Login.”
Information and services customized for your specific vehicle — all in one convenient place.
...
Fuel
For diesel engine vehicles, see “Fuel for Diesel Engines” in the Duramax Diesel Supplement.
For Vehicles with gasoline engines, please read this. ...