2004 GMC YUKON DENALI fuel

Checking Things Under
the Hood
{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 located
inside the vehicle to
the lower left of
the steering wheel.
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A. Engine Air Cleaner/Filter. SeeEngine Air
Cleaner/Filter on page 5-18.
B. Coolant Surge Tank. See
Engine Coolant on
page 5-23.
C. Air Filter Restriction Indicator. See
Engine Air
Cleaner/Filter on page 5-18.
D. Engine Oil Dipstick. See
Engine Oil on page 5-13.
E. Engine Oil Fill. See
Engine Oil on page 5-13.
F. Automatic Transmission Dipstick. See
Automatic
Transmission Fluid on page 5-20.
G. Fan. See
Cooling System on page 5-28.
H. Remote Negative (-) Terminal (GND). See
Jump
Starting on page 5-40.
I. Remote Positive (+) Terminal. See
Jump Starting on
page 5-40.
J. Power Steering Fluid Reservoir (Out of View). See
Power Steering Fluid on page 5-34.
K. Brake Master Cylinder Reservoir. See
Brakes on
page 5-36.
L. Underhood Fuse Block. See
Fuses and Circuit
Breakers on page 5-103.
M. Battery. See
Battery on page 5-39.
N. Windshield Washer Fluid Reservoir. See
Windshield
Washer Fluid on page 5-35.
Before closing the hood, be sure all ®ller caps are on
properly. Pull down the hood and close it ®rmly.
Engine Oil
If the CHECK OIL LEVEL message appears on the
instrument cluster, it means you need to check
your engine oil level right away.
For more information, see ªCHECK OIL LEVELº under
DIC Warnings and Messages on page 3-57.
You should check your engine oil level regularly; this is
an added reminder.
Checking Engine Oil
It is a good idea to check your engine oil every time you
get fuel. In order to get an accurate reading, the oil
must be warm and the vehicle must be on level ground.
The engine oil dipstick handle is a yellow loop. See
Engine Compartment Overview on page 5-12for
the location of the engine oil dipstick.
Turn off the engine and give the oil several minutes to
drain back into the oil pan. If you don't, the oil
dipstick might not show the actual level.
Pull out the dipstick and clean it with a paper towel or
cloth, then push it back in all the way. Remove it again,
keeping the tip down, and check the level.
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Notice:Use only engine oil identi®ed as meeting
GM Standard GM6094M and showing the American
Petroleum Institute Certi®ed For Gasoline Engines
starburst symbol. Failure to use the recommended
oil can result in engine damage not covered by
your warranty.
GM Goodwrench
žoil meets all the requirements for
your vehicle.
If you are in an area of extreme cold, where the
temperature falls below-20ÉF (-29ÉC), it is
recommended that you use either an SAE 5W-30
synthetic oil or an SAE 0W-30 oil. Both will provide
easier cold starting and better protection for your engine
at extremely low temperatures.
Engine Oil Additives
Do not add anything to your oil. The recommended oils
with the starburst symbol that meet GM Standard
GM6094M are all you will need for good performance
and engine protection.
When to Change Engine Oil (GM Oil
Life System)
Your vehicle has a computer system that lets you know
when to change the engine oil and ®lter. This is
based on engine revolutions and engine temperature,
and not on mileage. Based on driving conditions,
the mileage at which an oil change will be indicated can
vary considerably. For the oil life system to work
properly, you must reset the system every time the oil is
changed.
When the system has calculated that oil life has been
diminished, it will indicate that an oil change is
necessary. A CHANGE ENGINE OIL message will
come on. Change your oil as soon as possible within
the next two times you stop for fuel. It is possible that, if
you are driving under the best conditions, the oil life
system may not indicate that an oil change is necessary
for over a year. However, your engine oil and ®lter
must be changed at least once a year and at this time
the system must be reset. Your dealer has GM-trained
service people who will perform this work using
genuine GM parts and reset the system. It is also
important to check your oil regularly and keep it at the
proper level.
If the system is ever reset accidentally, you must
change your oil at 3,000 miles (5 000 km) since your
last oil change. Remember to reset the oil life system
whenever the oil is changed.
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4. With the coolant surge tank pressure cap off, start
the engine and let it run until you can feel the upper
radiator hose getting hot. Watch out for the
engine cooling fan.
By this time, the coolant level inside the coolant
surge tank may be lower. If the level is lower, add
more of the proper mixture to the coolant surge tank
until the level reaches FULL COLD mark.
5. Then replace the pressure cap. Be sure the
pressure cap is hand-tight and fully seated.
Engine Fan Noise
Your vehicle has a clutched engine cooling fan. When
the clutch is engaged, the fan spins faster to provide
more air to cool the engine. In most everyday driving
conditions, the fan is spinning slower and the clutch is
not fully engaged. This improves fuel economy and
reduces fan noise. Under heavy vehicle loading, trailer
towing and/or high outside temperatures, the fan
speed increases as the clutch more fully engages.
So you may hear an increase in fan noise. This
is normal and should not be mistaken as the
transmission slipping or making extra shifts. It is merely
the cooling system functioning properly. The fan will
slow down when additional cooling is not required and
the clutch disengages.
You may also hear this fan noise when you start the
engine. It will go away as the fan clutch partially
disengages.
5-33

Tire Terminology and De®nitions
Air Pressure:The amount of air inside the tire pressing
outward on each square inch of the tire. Air pressure
is expressed in pounds per square inch (psi) or
kilopascal (kPa).
Accessory Weight:This means the combined weight
of optional accessories. Some examples of optional
accessories are, automatic transmission, power steering,
power brakes, power windows, power seats, and air
conditioning.
Aspect Ratio:The relationship of a tire's height
to its width.
Belt:A rubber coated layer of cords that is located
between the plies and the tread. Cords may be made
from steel or other reinforcing materials.
Bead:The tire bead contains steel wires wrapped by
steel cords that hold the tire onto the rim.
Bias Ply Tire:A pneumatic tire in which the plies are
laid at alternate angles less than 90 degrees to the
centerline of the tread.Cold In¯ation Pressure:The amount of air pressure in
a tire, measured in pounds per square inch (psi) or
kilopascals (kPa) before a tire has built up heat
from driving. SeeIn¯ation - Tire Pressure on page 5-62.
Curb Weight:This means the weight of a motor
vehicle with standard and optional equipment including
the maximum capacity of fuel, oil and coolant, but
without passengers and cargo.
DOT Markings:A code molded into the sidewall of a
tire signifying that the tire is in compliance with the U.S.
Department of Transportation motor vehicle safety
standards. The DOT code includes the Tire Identi®cation
Number (TIN), an alphanumeric designator which can
also identify the tire manufacturer, production plant,
brand and date of production.
GVWR:Gross Vehicle Weight Rating, see
Loading
Your Vehicle on page 4-44.
GAWR FRT:Gross Axle Weight Rating for the front
axle, see
Loading Your Vehicle on page 4-44.
GAWR RR:Gross Axle Weight Rating for the rear axle,
see
Loading Your Vehicle on page 4-44.
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Notice:Don't let anyone tell you that underin¯ation
or overin¯ation is all right. It's not. If your tires
don't have enough air (underin¯ation), you can get
the following:
·Too much ¯exing
·Too much heat
·Tire overloading
·Bad wear
·Bad handling
·Bad fuel economy
If your tires have too much air (overin¯ation), you
can get the following:
·Unusual wear
·Bad handling
·Rough ride
·Needless damage from road hazards
When to Check
Check your tires once a month or more.
Also, check the tire pressure of the spare tire.
How to Check
Use a good quality pocket-type gage to check tire
pressure. You can't tell if your tires are properly in¯ated
simply by looking at them. Radial tires may look
properly in¯ated even when they're underin¯ated. Check
the tire's in¯ation 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 in¯ation pressure matches
the recommended pressure on the tire and loading
information label, no further adjustment is necessary.
If the pressure is low, add air until you reach the
recommended amount.
If you over®ll 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.
5-63

Tire Pressure Monitor System
The Tire Pressure Monitor (TPM) system uses radio
and sensor technology to check tire pressure levels.
If your vehicle has this feature, sensors are mounted on
each tire and wheel assembly, except the spare tire.
The TPM sensors transmit tire pressure readings
to a receiver located in the vehicle.
When a low tire pressure condition is detected, the TPM
system will display the CHECK TIRE PRESSURE
warning message on the Driver Information Center
(DIC); and at the same time illuminate the low tire
pressure warning symbol. For additional information and
details about the DIC operation and displays see DIC
Operation and Displays on page 3-46andDIC Warnings
and Messages on page 3-57.
When the tire pressure
monitoring system warning
light is lit, one or more
of your tires is signi®cantly
under-in¯ated.
You should stop and check your tires as soon as
possible, and in¯ate them to the proper pressure as
indicated on the vehicle's tire information placard.Driving on a signi®cantly under-in¯ated tire causes the
tire to overheat and can lead to tire failure.
Under-in¯ation also reduces fuel efficiency and tire tread
life, and may affect the vehicle's handling and stopping
ability. Each tire, including the spare, should be
checked monthly when cold and set to the
recommended in¯ation pressure as speci®ed in the
vehicle placard and owner's manual.
The Certi®cation/Tire label or the Tire and Loading
Information label (tire information placard) shows the
size of your vehicle's original tires and the correct
in¯ation pressure for your vehicle's tires when they are
cold. See
In¯ation - Tire Pressure on page 5-62. For
the location of the tire and loading information label, see
Loading Your Vehicle on page 4-44.
Your vehicle's TPM system can alert you about a low
tire pressure condition but it does not replace normal tire
maintenance. See
Tire Inspection and Rotation on
page 5-66andTires on page 5-54.
Notice:Do not use a tire sealant if your vehicle is
equipped with Tire Pressure Monitors. The liquid
sealant can damage the tire pressure monitor
sensors.
5-64

Cleaning Tires
To clean your tires, use a stiff brush with tire cleaner.
Notice:Using petroleum-based tire dressing
products on your vehicle may damage the paint
®nish and/or tires. When applying a tire dressing,
always wipe off any overspray from all painted
surfaces on your vehicle.
Sheet Metal Damage
If your vehicle is damaged and requires sheet metal
repair or replacement, make sure the body repair shop
applies anti-corrosion material to parts repaired or
replaced to restore corrosion protection.
Original manufacturer replacement parts will provide the
corrosion protection while maintaining the warranty.
Finish Damage
Any stone chips, fractures or deep scratches in the
®nish should be repaired right away. Bare metal
will corrode quickly and may develop into major repair
expense.
Minor chips and scratches can be repaired with touch-up
materials avaliable from your dealer. Larger areas of
®nish damage can be corrected in your dealer's
body and paint shop.
Underbody Maintenance
Chemicals used for ice and snow removal and dust
control can collect on the underbody. If these are not
removed, corrosion and rust can develop on the
underbody parts such as fuel lines, frame, ¯oor pan and
exhaust system even though they have corrosion
protection.
At least every spring, ¯ush these materials from the
underbody with plain water. Clean any areas where mud
and debris can collect. Dirt packed in close areas of
the frame should be loosened before being ¯ushed.
Your dealer or an underbody car washing system can
do this for you.
5-99