1996 GMC Sonoma Owner's Manual - Page 110

Check GagesLight The CHECK GAGES light will come on briefly when you are starting the engine. Fuel Gage When the ignition is on, the fuel gage tells you about how much fuel you have remaining. CHECK GAGES FUEL If the light comes on and stays on while you are driving, check your coolant temperature and engine oil pressure gages to see if they are in the warning zones. Here are fourthings that some owners ask about. None of these show a problem with your fuel gage: At the gas station, the gas pump shuts off before the gage reads FULL (F). It takes a little more or less fuel to fill up than the gage indicated. For example, the gage may have indicated the tank was half full, but it 'actuallytook a little more or less than half the tank'scapacity to fill the tank. The gage moves a little when you turn a corner or speed up. The gage doesn't go back to EMPTY (E) when you turn off the ignition. - 2-62