Page 158 of 408

Tow/Haul Mode Light
This light comes on when
the Tow/Haul mode has
been activated.
For more information, seeTow/Haul Mode on page 2-25.
Fuel Gage
The fuel gage, when the ignition is on, indicates how
much fuel is left in the vehicle’s fuel tank.An arrow on the fuel gage indicates the side of the
vehicle the fuel door is on.
The gage first indicates empty before the vehicle is out
of fuel, and the fuel tank should be refueled soon.
Listed are four situations customers might experience
with the fuel gage. None of these indicate a problem with
the fuel gage:
•At the gas station, the fuel pump shuts off before
the gage reads full.
•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 while turning a corner or
speeding up.
•The gage does not go back to empty when the
ignition is turned off.
If the vehicle has the DURAMAX Diesel engine, see the
DURAMAX Diesel manual for more information.
United StatesCanada
3-40
Page 252 of 408

Fuel E85 (85% Ethanol)
The 8th digit of the Vehicle Identification Number (VIN)
shows the code letter or number that identifies the
vehicle’s engine. The VIN is at the top left of the
instrument panel. SeeVehicle Identification
Number (VIN) on page 5-104.
If the vehicle has the 5.3L V8 engine (VIN Code 4) and
the N15 flexible fuel option, you can use either unleaded
gasoline or ethanol fuel containing up to 85% ethanol
(E85). SeeFuel on page 5-5. For the 5.3L V8 engine
(VIN Code 4) without the N15 option and all other
gasoline engines, use only the unleaded gasoline
described underGasoline Octane on page 5-6.
Only vehicles that have the 5.3L V8 engine
(VIN Code 4) and the N15 flexible fuel option can
use 85% ethanol fuel (E85). We encourage the use of
E85 in vehicles that are designed to use it. The ethanol
in E85 is a “renewable” fuel, meaning it is made from
renewable sources such as corn and other crops.
Many service stations will not have an 85% ethanol fuel
(E85) pump available. The U. S. Department of Energy
has an alternative fuels website (www.eere.energy.gov/
afdc/infrastructure/locator.html) that can help you findE85 fuel. Those stations that do have E85 should have a
label indicating ethanol content. Do not use the fuel if the
ethanol content is greater than 85%.
At a minimum, E85 should meet ASTM Specification
D 5798. By definition, this means that fuel labeled E85
will have an ethanol content between 70% and 85%.
Filling the fuel tank with fuel mixtures that do not meet
ASTM specifications can affect driveability and could
cause the malfunction indicator lamp to come on.
To ensure quick starts in the wintertime, the E85 fuel
must be formulated properly for your climate according to
ASTM specification D 5798. If you have trouble starting
on E85, it could be because the E85 fuel is not properly
formulated for your climate. If this happens, switching to
gasoline or adding gasoline to the fuel tank can improve
starting. For good starting and heater efficiency below
32°F (0°C), the fuel mix in the fuel tank should contain
no more than 70% ethanol. It is best not to alternate
repeatedly between gasoline and E85. If you do switch
fuels, it is recommended that you add as much fuel as
possible — do not add less than three gallons (11 L)
when refueling. You should drive the vehicle immediately
after refueling for at least seven miles (11 km) to allow the
vehicle to adapt to the change in ethanol concentration.
5-8
Page 254 of 408

Filling the Tank
{CAUTION:
Fuel vapor burns violently and a fuel fire can
cause bad injuries. To help avoid injuries to you
and others, read and follow all the instructions on
the pump island. Turn off the engine when you are
refueling. Do not smoke if you are near fuel or
refueling the vehicle. Do not use cellular phones.
Keep sparks, flames, and smoking materials away
from fuel. Do not leave the fuel pump unattended
when refueling the vehicle. This is against the law
in some places. Do not re-enter the vehicle while
pumping fuel. Keep children away from the fuel
pump; never let children pump fuel.The tethered fuel cap is
located behind a hinged
fuel door on the driver side
of the vehicle.
If the vehicle has E85 fuel capability, the fuel cap will be
yellow and state that E85 or gasoline can be used.
SeeFuel E85 (85% Ethanol) on page 5-8.
To remove the fuel cap, turn it slowly counterclockwise.
While refueling, hang the tethered fuel cap from the
hook on the fuel door.
5-10
Page 255 of 408

{CAUTION:
Fuel can spray out on you if you open the fuel cap
too quickly. If you spill fuel and then something
ignites it, you could be badly burned. 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.
Be careful not to spill fuel. Do not top off or overfill the
tank and wait a few seconds after you have finished
pumping before removing the nozzle. Clean fuel from
painted surfaces as soon as possible. SeeWashing
Your Vehicle on page 5-100.
When replacing the fuel cap, turn it clockwise until it
clicks. Make sure the cap is fully installed. 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. SeeMalfunction Indicator Lamp
on page 3-34.
{CAUTION:
If a fire starts while you are refueling, do not
remove the nozzle. Shut off the flow of fuel by
shutting off the pump or by notifying the station
attendant. Leave the area immediately.
Notice:If you need a new fuel cap, be sure to get
the right type. Your dealer/retailer can get one
for you. If you get the wrong type, it may not t
properly. This may cause the malfunction indicator
lamp to light and may damage the fuel tank and
emissions system. SeeMalfunction Indicator Lamp
on page 3-34.
5-11
Page 256 of 408

Filling a Portable Fuel Container
{CAUTION:
Never fill a portable fuel container while it is in
the vehicle. Static electricity discharge from the
container can ignite the fuel vapor. You can be
badly burned and the vehicle damaged if this
occurs. To help avoid injury to you and others:
•Dispense fuel only into approved containers.
•Do not fill a container while it is inside a
vehicle, in a vehicle’s trunk, pickup bed,
or on any surface other than the ground.
•Bring the fill nozzle in contact with the inside
of the fill opening before operating the nozzle.
Contact should be maintained until the filling
is complete.
•Do not smoke while pumping fuel.
•Do not use a cellular phone while
pumping fuel.
Checking Things Under
the Hood
{CAUTION:
Things that burn can get on hot engine or fuel
operated heater (FOH) parts and start a fire.
These include liquids like fuel, oil, coolant, brake
fluid, windshield washer and other fluids, and
plastic or rubber. You or others could be burned.
Be careful not to drop or spill things that will burn
onto a hot engine or fuel operated heater (FOH).
5-12
Page 352 of 408
Fuse Usage
1 Left High-Beam Headlamp
2 Fuel Pump
3 Empty
4 Fuel Heater (Diesel)Fuse Usage
5 Right High-Beam Headlamp
6 Empty
7 Left Low-Beam Headlamp
8 Right Stoplamp, Trailer Turn Signal
5-108
Page 354 of 408

Fuse Usage
47Transmission Control Module
Ignition
48 Engine Control Module Ignition
49 Mass Airflow Sensor, Canister Vent
50 Engine Control Module, Powertrain
51 Transmission
52 Even Ignition Injectors (Gas)
53 Glow Plug Module (Diesel)
54 Engine Control Module Battery
55 Odd Ignition Injectors (Gas)
56 Oxygen Sensor 2 (Gas)
57 Air Conditioning Compressor
58 Fan Clutch (Diesel)
59 V6 Fuel Injectors (Gas)
60Antilock Brake System Module
(J-Case)
61Antilock Brake System Motor
(J-Case)
62 Trailer Wiring (J-Case)
63 EmptyFuse Usage
64 Starter Solenoid (J-Case)
65Engine Control Module (ECM),
Powertrain (Diesel) (J-Case)
66 Front Blower (J-Case)
67 Empty
77 Body BEC (Mega Fuse)
Relays Usage
68 Empty
69 Run, Crank (High Current Micro)
70Windshield Wiper High
(High Current Micro)
71Windshield Wiper
(High Current Micro)
72 Fuel Pump (Mini Micro)
73 Crank (High Current Micro)
74Air Conditioning Compressor
(Mini Micro)
75 Fan Clutch (Diesel) (Solid State)
76 Powertrain (High Current Micro)
5-110