GMC Sierra/Sierra Denali 2500 HD/3500 HD Owner Manual (GMNA-
Localizing-U.S./Canada/Mexico-14632286) - 2021 - CRC - 11/19/20
Driving and Operating
273
{
Warning
Attempting to refuel from a portable fuel
container without using the funnel
adapter may cause fuel spillage and
damage the capless fuel system. This
could cause a fire. You or others could be
badly burned and the vehicle could be
damaged.
3. Remove and clean the funnel adapter
and return it to the storage location.
Filling the Tank (Chassis Cab and
Box Delete Models)
If the vehicle has a diesel engine, see the
Duramax diesel supplement.
An arrow on the fuel gauge indicates which
side of the vehicle the fuel fill is on. See
{
Warning
Fuel vapors and fuel fires burn violently
and can cause injury or death.
Follow these guidelines to help avoid
injuries to you and others:
.
Read and follow all the instructions on
the fuel pump island.
.
Turn off the engine when refueling.
.
Keep sparks, flames, and smoking
materials away from fuel.
.
Do not leave the fuel pump
unattended.
.
Avoid using electronic devices while
refueling.
.
Do not re-enter the vehicle while
pumping fuel.
.
Keep children away from the fuel
pump and never let children
pump fuel.
.
Before touching the fill nozzle, touch a
metallic object to discharge static
electricity from your body.
(Continued)
Warning (Continued)
.
Fuel can spray out if the fuel cap is
opened too quickly. This spray can
happen if the 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.
Turn the fuel cap counterclockwise to
remove. Fully insert and latch the fill nozzle,
begin fueling. For models with dual fuel
tanks, the fuel gauge shows an average of
both tanks. When refueling, refuel the
primary front tank first, then add fuel to the
auxiliary rear tank.
{
Warning
Overfilling the fuel tank by more than
three clicks of a standard fill nozzle may
cause:
.
Vehicle performance issues, including
engine stalling and damage to the fuel
system.
.
Fuel spills.
.
Under certain conditions, fuel fires.
