GMC 1994 Yukon Owner's Manual page 131

Listed are four situations you may experience with your fuel gage:
At the gas station, the fuel pump shuts
off
before the gage reads full.
0
It takes a little more or less fuel to fill up than the fuel gage indicated.
For example, the gage may have indicated the tank was half full, but it
actually took a little more or less than half the tank's capacity to fill the
tank.
The gage moves a little when you turn a corner or speed up.
0
The gage doesn't go back to empty when you turn off the ignition.
None of these indicate a problem with the fuel gage.
For information on how to fill your fuel tank, see "Fuel
-
Filling Your
Tank" in the Index.
For your fuel tank capacity, see "Fuel -Tank Capacity" in the Index.
Engine Coolant Temperature Gage
This gage shows the engine coolant temperature. If the gage pointer moves
into the red area, about 260°F
(
145°C) or more, your engine is too hot! It
means that your engine coolant has overheated. If you have been operating
your vehicle under normal operating conditions, you should pull off the
road, stop your vehicle, and turn off the engine as soon as possible.
Hot Coolant Can Burn You Badly!
In "Problems on the Road," this manual shows what to do. See "Engine
Overheating" in the Index.
2-75