2008 HUMMER H3 fuel cap release

Fuel Gage
When the ignition is on, the fuel gage tells you about
how much fuel you have remaining in the fuel tank.
Here are three things that some owners ask about. None
of these indicate a problem with your fuel gage:
At the gas station, the gas pump shuts off before
the gage reads full.
It takes a little more or less fuel to ll up than the
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
ll the tank.
The gage moves a little when you turn a corner or
speed up.When the fuel in the fuel tank is low, you will see a
LOW FUEL message on the Driver Information
Center (DIC) display. SeeDIC Warnings and Messages
on page 3-43for more information.
Driver Information Center (DIC)
The Driver Information Center (DIC) displays information
such as the trip odometer, personalization features,
and warning messages. The DIC display is located on
the instrument panel cluster.
DIC Operation and Displays
The Driver Information Center (DIC) comes on when the
ignition is on.
If a problem is detected, a warning message appears
on the display. Pressing and releasing the trip odometer
reset stem on the DIC acknowledges some current
warnings or service messages. Some messages only
clear after the required action has been taken.
The DIC has different modes which can be accessed by
pressing the trip odometer reset stem on the DIC.
These modes are explained in the following section.
The DIC trip odometer reset stem is located on
the instrument panel cluster next to the DIC display.
To scroll through the available functions, press
and release the reset stem. United States
Canada
3-40

FLUID
This message displays if the brake uid is low. Check
the brake uid as soon as possible and have your
vehicle serviced by your dealer/retailer. SeeBrakes on
page 5-38for more information. Press and release
the reset stem to acknowledge the message and clear it
from the display.
FUEL CAP
This message displays if the vehicle’s fuel cap is either
off or loose. Pull over as soon as possible and check
to see if the fuel cap is secure. You may also see
the check engine light on the instrument panel cluster.
If the check engine light does come on when the
fuel cap was loose, it may take a few driving trips before
the light turns off. SeeMalfunction Indicator Lamp on
page 3-36for more information if the light still remains
on. Press and release the reset stem to acknowledge
the message and clear it from the display.
LOW FUEL
This message displays if the level of fuel in the vehicle
is low. Also check the fuel gage. SeeFuel Gage on
page 3-40for more information. Rell the fuel tank as
soon as possible.
LOW TIRE
This message displays if a low tire pressure is detected
in any of the vehicle’s tires. Press and release the reset
stem to acknowledge the message and clear it from the
display. The message appears at each ignition cycle until
the tires are inated to the correct ination pressure. See
Tires on page 5-54andInflation - Tire Pressure on
page 5-62for more information on tires and the correct
ination pressures.
OIL
This message displays when the oil pressure is low.
SeeOil Pressure Light on page 3-38andEngine Oil
on page 5-15for more information.
PARK BRK (Brake)
This message displays when the parking brake is set.
SeeParking Brake on page 2-32andBrake System
Warning Light on page 3-33for more information. The
message clears from the display after the parking brake
is released or by pressing and releasing the reset stem.
3-45

Service............................................................5-3
Accessories and Modications..........................5-3
California Proposition 65 Warning.....................5-4
California Perchlorate Materials Requirements.....5-4
Doing Your Own Service Work.........................5-4
Adding Equipment to the Outside of
Your Vehicle..............................................5-5
Fuel................................................................5-5
Gasoline Octane............................................5-5
Gasoline Specications....................................5-5
California Fuel...............................................5-6
Additives.......................................................5-6
Fuels in Foreign Countries...............................5-7
Filling the Tank..............................................5-8
Filling a Portable Fuel Container.....................5-10
Checking Things Under the Hood....................5-11
Hood Release..............................................5-11
Engine Compartment Overview.......................5-12
Engine Oil...................................................5-15
Engine Oil Life System..................................5-18
Engine Air Cleaner/Filter................................5-20
Automatic Transmission Fluid.........................5-21
Manual Transmission Fluid.............................5-24
Hydraulic Clutch...........................................5-26Engine Coolant.............................................5-27
Radiator Pressure Cap..................................5-29
Engine Overheating.......................................5-29
Cooling System............................................5-31
Engine Fan Noise.........................................5-36
Power Steering Fluid.....................................5-36
Windshield Washer Fluid................................5-37
Brakes........................................................5-38
Battery........................................................5-41
Jump Starting...............................................5-42
Rear Axle
.......................................................5-45
Four-Wheel Drive............................................5-46
Front Axle......................................................5-46
Headlamp Aiming...........................................5-46
Bulb Replacement..........................................5-49
Halogen Bulbs..............................................5-49
Headlamps..................................................5-49
Taillamps, Turn Signal, Stoplamps and
Back-up Lamps.........................................5-50
License Plate Lamp......................................5-51
Replacement Bulbs.......................................5-52
Windshield Wiper Blade Replacement..............5-52
Section 5 Service and Appearance Care
5-1

Checking Things Under
the Hood
{CAUTION:
An electric fan under the hood can start up
and injure you even when the engine is not
running. Keep hands, clothing, and tools away
from any underhood electric fan.
{CAUTION:
Things that burn can get on hot engine parts
and start a re. These include liquids like fuel,
oil, coolant, brake uid, windshield washer and
other uids, 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.
Hood Release
To open the hood, do the following:
1. Pull the handle with
this symbol on it. It is
located inside the
vehicle on the lower
left side of the
instrument panel.
2. Release the secondary latch on the hood. It is
located below the front center of the hood.
3. Lift the hood.
Before closing the hood, be sure all the ller caps are
on properly. Then pull the hood down and close it rmly.
5-11

How to Check
Use a good quality pocket-type gage to check
tire pressure. You cannot tell if your tires are
properly inated simply by looking at them. Radial
tires may look properly inated even when they
are underinated. Check the tire’s ination
pressure when the tires are cold. Cold means your
vehicle has been sitting for at least three hours
or driven no more than 1 mile (1.6 km).
Remove the valve cap from the tire valve stem.
Press the tire gage rmly onto the valve to
get a pressure measurement. If the cold tire
ination pressure matches the recommended
pressure on the Tire and Loading Information
label, no further adjustment is necessary. If the
ination pressure is low, add air until you reach the
recommended amount.
If you overll the tire, release air by pushing on
the metal stem in the center of the tire valve.
Recheck the tire pressure with the tire gage.
Be sure to put the valve caps back on the valve
stems. They help prevent leaks by keeping out dirt
and moisture.
Tire Pressure Monitor System
The Tire Pressure Monitor System (TPMS) uses radio
and sensor technology to check tire pressure levels.
The TPMS sensors monitor the air pressure in
your vehicle’s tires and transmit tire pressure readings
to a receiver located in the vehicle.
Each tire, including the spare (if provided), should be
checked monthly when cold and inated to the ination
pressure recommended by the vehicle manufacturer
on the vehicle placard or tire ination pressure label.
(If your vehicle has tires of a different size than the
size indicated on the vehicle placard or tire ination
pressure label, you should determine the proper
tire ination pressure for those tires.)
As an added safety feature, your vehicle has been
equipped with a tire pressure monitoring system (TPMS)
that illuminates a low tire pressure telltale when one
or more of your tires is signicantly under-inated.
Accordingly, when the low tire pressure telltale
illuminates, you should stop and check your tires as
soon as possible, and inate them to the proper
pressure. Driving on a signicantly under-inated tire
causes the tire to overheat and can lead to tire failure.
Under-ination also reduces fuel efficiency and tire
tread life, and may affect the vehicle’s handling
and stopping ability.
5-63

(d)Inspect wiper blades for wear, cracking, or
contamination. Clean the windshield and wiper blades, if
contaminated. Replace wiper blades that are worn or
damaged. See Windshield Wiper Blade Replacement on
page 5-52 and Windshield, Backglass, and Wiper
Blades on page 5-97 for more information.
(e)Make sure the safety belt reminder light and safety
belt assemblies are working properly. Look for any
other loose or damaged safety belt system parts. If you
see anything that might keep a safety belt system
from doing its job, have it repaired. Have any torn or
frayed safety belts replaced. Also see Checking
the Restraint Systems on page 1-69.
(f)Lubricate all key lock cylinders, hood latch assembly,
secondary latch, pivots, spring anchor, release pawl,
rear compartment hinges, outer swing-gate handle pivot
points, rear door detent link, roller mechanism,
swing-gate handle pivot points, latch bolt, fuel door
hinge, locks, and folding seat hardware. More frequent
lubrication may be required when exposed to a
corrosive environment. Applying silicone grease on
weatherstrips with a clean cloth will make them
last longer, seal better, and not stick or squeak.(g)Check vent hose at transfer case for kinks and
proper installation.
(h)Change automatic transmission fluid and filter if the
vehicle is mainly driven under one or more of these
conditions:
In heavy city traffic where the outside temperature
regularly reaches 90°F (32°C) or higher.
In hilly or mountainous terrain.
When doing frequent trailer towing.
Uses such as found in taxi, police, or delivery
service.
(i)Drain, flush, and refill cooling system. This service
can be complex; you should have your dealer/retailer
perform this service. See Engine Coolant on page 5-27
for what to use. Inspect hoses. Clean radiator,
condenser, pressure cap, and filler neck. Pressure test
the cooling system and pressure cap.
(j)A fluid loss in any vehicle system could indicate a
problem. Have the system inspected and repaired and
the fluid level checked. Add fluid if needed.
(k)Visually inspect belt for fraying, excessive cracks, or
obvious damage. Replace belt if necessary.
6-8