2004 GMC YUKON DENALI coolant temperature

Driving On Grades
Reduce speed and shift to a lower gearbeforeyou start
down a long or steep downgrade. If you don't shift
down, you might have to use your brakes so much that
they would get hot and no longer work well.
You can tow in DRIVE (D). You may want to shift the
transmission to THIRD (3) or, if necessary, a lower gear
selection if the transmission shifts too often (e.g.,
under heavy loads and/or hilly conditions).
You may also want to activate the tow/haul mode if the
transmission shifts too often. See ªTow/Haul Modeº
under
Towing a Trailer on page 4-51.
When towing at high altitude on steep uphill grades,
consider the following: Engine coolant will boil at a lower
temperature than at normal altitudes. If you turn your
engine off immediately after towing at high altitude
on steep uphill grades, your vehicle may show signs
similar to engine overheating. To avoid this, let the
engine run while parked (preferably on level ground)
with the automatic transmission in PARK (P) for a
few minutes before turning the engine off. If you do get
the overheat warning, see
Engine Overheating on
page 5-25.
Parking on Hills
{CAUTION:
You really should not park your vehicle, with a
trailer attached, on a hill. If something goes
wrong, your rig could start to move. People
can be injured, and both your vehicle and the
trailer can be damaged.
But if you ever have to park your rig on a hill, here's
how to do it:
1. Apply your regular brakes, but don't shift into
PARK (P) yet.
2. Have someone place chocks under the trailer
wheels.
3. When the wheel chocks are in place, release the
regular brakes until the chocks absorb the load.
4. Reapply the regular brakes. Then apply your
parking brake and shift into PARK (P).
5. Release the regular brakes.
4-60

Engine Coolant
The cooling system in your vehicle is ®lled with
DEX-COOLžengine coolant. This coolant is designed
to remain in your vehicle for 5 years or 150,000 miles
(240 000 km), whichever occurs ®rst, if you add
only DEX-COOL
žextended life coolant.
The following explains your cooling system and how to
add coolant when it is low. If you have a problem
with engine overheating, see
Engine Overheating on
page 5-25.
A 50/50 mixture of clean, drinkable water and
DEX-COOL
žcoolant will:
·Give freezing protection down to-34ÉF (-37ÉC).
·Give boiling protection up to 265ÉF (129ÉC).
·Protect against rust and corrosion.
·Help keep the proper engine temperature.
·Let the warning lights and gages work as they
should.
Notice:Using coolant other than DEX-COOLžmay
cause premature engine, heater core or radiator
corrosion. In addition, the engine coolant may
require changing sooner, at 30,000 miles (50 000 km)
or 24 months, whichever occurs ®rst. Any repairs
would not be covered by your warranty. Always use
DEX-COOL
ž(silicate-free) coolant in your vehicle.
What to Use
Use a mixture of one-halfclean, drinkable waterand
one-half DEX-COOLžcoolant which won't damage
aluminum parts. If you use this coolant mixture,
you don't need to add anything else.
{CAUTION:
Adding only plain water to your cooling
system can be dangerous. Plain water, or
some other liquid such as alcohol, can boil
before the proper coolant mixture will. Your
vehicle's coolant warning system is set for the
proper coolant mixture. With plain water or the
wrong mixture, your engine could get too hot
but you would not get the overheat warning.
Your engine could catch ®re and you or others
could be burned. Use a 50/50 mixture of clean,
drinkable water and DEX-COOL
žcoolant.
Notice:If you use an improper coolant mixture,
your engine could overheat and be badly damaged.
The repair cost would not be covered by your
warranty. Too much water in the mixture can freeze
and crack the engine, radiator, heater core and
other parts.
5-23

Adding Coolant
If you need more coolant, add the proper DEX-COOLž
coolant mixtureat the surge tank, but only when the
engine is cool.
{CAUTION:
You can be burned if you spill coolant on hot
engine parts. Coolant contains ethylene glycol,
and it will burn if the engine parts are hot
enough. Do not spill coolant on a hot engine.
When replacing the pressure cap, make sure it is
hand-tight.
Coolant Surge Tank Pressure Cap
The coolant surge tank pressure cap must be fully
installed on the coolant surge tank. SeeEngine
Compartment Overview on page 5-12for more
information on location.
Notice:If the pressure cap is not tightly installed,
coolant loss and possible engine damage may
occur. Be sure the cap is properly and tightly
secured.
Engine Overheating
You will ®nd a coolant temperature gage on your
vehicle's instrument panel. SeeEngine Coolant
Temperature Gage on page 3-38. In addition, you will
®nd an ENGINE COOLANT HOT, ENGINE
OVERHEATED and a REDUCED ENGINE POWER
message in the DIC on the instrument panel. See
DIC
Warnings and Messages on page 3-57.
Overheated Engine Protection
Operating Mode
If an overheated engine condition exists and the
REDUCED ENGINE POWER message is displayed, an
overheat protection mode which alternates ®ring
groups of cylinders helps prevent engine damage. In
this mode, you will notice a loss in power and engine
performance. This operating mode allows your vehicle to
be driven to a safe place in an emergency. Driving
extended miles (km) and/or towing a trailer in the
overheat protection mode should be avoided.
Notice:After driving in the overheated engine
protection operating mode, to avoid engine damage,
allow the engine to cool before attempting any
repair. The engine oil will be severely degraded.
Repair the cause of coolant loss, change the oil and
reset the oil life system. See
Engine Oil on
page 5-13.
5-25

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

What to Use
To determine what kind of ¯uid to use, seeRecommended Fluids and Lubricants on page 6-13.
Always use the proper ¯uid. Failure to use the proper
¯uid can cause leaks and damage hoses and seals.
Windshield Washer Fluid
What to Use
When you need windshield washer ¯uid, be sure to read
the manufacturer's instructions before use. If you will
be operating your vehicle in an area where the
temperature may fall below freezing, use a ¯uid that has
sufficient protection against freezing. See
Engine
Compartment Overview on page 5-12for reservoir
location.
Adding Washer Fluid
Your vehicle has a low washer ¯uid message that
comes on when the washer ¯uid is low. The message is
displayed for 15 seconds at the start of each ignition
cycle. When the CHECK WASHER FLUID message is
displayed, you will need to add washer ¯uid to the
windshield washer ¯uid reservoir.The windshield washer
¯uid reservoir is located in
the engine compartment
toward the front of the
vehicle on the driver's side.
Open the cap with the washer symbol on it. Add washer
¯uid until the tank is full.
Notice:
·When using concentrated washer ¯uid, follow
the manufacturer's instructions for adding
water.
·Do not mix water with ready-to-use washer ¯uid.
Water can cause the solution to freeze and
damage your washer ¯uid tank and other parts
of the washer system. Also, water does not
clean as well as washer ¯uid.
·Fill your washer ¯uid tank only three-quarters
full when it is very cold. This allows for
expansion if freezing occurs, which could
damage the tank if it is completely full.
·Do not use engine coolant (antifreeze) in your
windshield washer. It can damage your washer
system and paint.
5-35

(g)Inspect system. Check all fuel and vapor lines and
hoses for proper hook-up, routing and condition.
Check that the purge valve works properly (if equipped).
Replace as needed.
(h)Change automatic transmission ¯uid and ®lter if the
vehicle is mainly driven under one or more of these
conditions:
þIn heavy city traffic where the outside temperature
regularly reaches 90ÉF (32ÉC) or higher.
þIn hilly or mountainous terrain.
þWhen doing frequent trailer towing.
þUses such as found in taxi, police or delivery
service.
(i)Drain, ¯ush and re®ll cooling system. See Engine
Coolant on page 5-23for what to use. Inspect hoses.
Clean radiator, condenser, pressure cap and ®ller neck.
Pressure test the cooling system and pressure cap.
(j)
A ¯uid loss in any vehicle system could indicate a
problem. Have the system inspected and repaired and
the ¯uid level checked. Add ¯uid if needed.
Owner Checks and Services
These owner checks and services should be performed
at the intervals speci®ed to help ensure the safety,
dependability and emission control performance of your
vehicle. Your GM Goodwrench dealer can assist you
with these checks and services.
Be sure any necessary repairs are completed at once.
Whenever any ¯uids or lubricants are added to your
vehicle, make sure they are the proper ones, as shown
in
Recommended Fluids and Lubricants on page 6-13.
At Each Fuel Fill
It is important to perform these underhood checks at
each fuel ®ll.
Engine Oil Level Check
Check the engine oil level and add the proper oil if
necessary. SeeEngine Oil on page 5-13for further
details.
Notice:It is important to check your oil regularly
and keep it at the proper level. Failure to keep your
engine oil at the proper level can cause damage
to your engine not covered by your warranty.
6-9

Cleaning Fabric/Carpet....................................5-93
Cleaning Glass Surfaces..................................5-95
Cleaning Interior Plastic Components.................5-94
Cleaning Leather............................................5-94
Cleaning the Mirror.........................................2-34
Cleaning the Speaker Covers...........................5-95
Cleaning the Top of the Instrument Panel...........5-94
Cleaning the Windshield, Backglass and Wiper
Blades.......................................................5-98
Cleaning Tires................................................5-99
Cleaning Vinyl................................................5-94
Cleaning Wood Panels....................................5-94
Climate Control System
Climate Controls Personalization....................3-29
Dual Automatic............................................3-20
Outlet Adjustment........................................3-26
Rear..........................................................3-27
Compass Calibration.......................................2-34
Compass Variance..........................................2-33
Content Theft-Deterrent....................................2-16
Control of a Vehicle.......................................... 4-5
Convenience Net............................................2-45
Coolant
Engine Temperature Gage............................3-38
Heater, Engine............................................2-21
Surge Tank Pressure Cap.............................5-25
Cooling System..............................................5-28
Cruise Control................................................3-11
Cruise Control Light........................................3-44
Cupholder(s)..................................................2-43Current and Past Model Order Forms................7-12
Customer Assistance Information
Courtesy Transportation.................................. 7-7
Customer Assistance for Text Telephone (TTY)
Users....................................................... 7-4
Customer Assistance Offices........................... 7-4
Customer Satisfaction Procedure..................... 7-2
GM Mobility Program for Persons with
Disabilities................................................ 7-5
Reporting Safety Defects to General Motors....7-11
Reporting Safety Defects to the Canadian
Government............................................7-10
Reporting Safety Defects to the United States
Government............................................7-10
Roadside Assistance Program......................... 7-5
Service Publications Ordering Information........7-11
D
Daytime Running Lamps..................................3-16
Defensive Driving............................................. 4-2
Defogging and Defrosting.................................3-25
Delayed Locking............................................... 2-9
Doing Your Own Service Work........................... 5-3
Dome Lamps.................................................3-17
Door
Delayed Locking........................................... 2-9
Locks.......................................................... 2-8
Power Door Locks......................................... 2-9
4

Door (cont.)
Programmable Automatic Door Locks.............2-10
Rear Door Security Locks.............................2-12
Driver
Position, Safety Belt.....................................1-30
DRIVER DOOR AJAR.....................................3-58
Driver Information Center (DIC).........................3-46
DIC Operation and Displays..........................3-46
DIC Warnings and Messages........................3-57
Driving
At Night.....................................................4-28
City...........................................................4-32
Defensive..................................................... 4-2
Drunken....................................................... 4-2
Freeway.....................................................4-33
Hill and Mountain Roads..............................4-35
In Rain and on Wet Roads...........................4-29
Winter........................................................4-37
Driving Across an Incline..................................4-24
Driving Downhill..............................................4-23
Driving in Mud, Sand, Snow or Ice....................4-26
Driving in Water..............................................4-27
Driving On Grades..........................................4-60
Driving on Off-Road Hills.................................4-20
Driving on Snow or Ice....................................4-38
Driving Through Deep Standing Water...............4-31
Driving Through Flowing Water.........................4-31
Driving Uphill..................................................4-21
Driving with a Trailer.......................................4-58
Dual Automatic Climate Control System.............3-20DVD
Cleaning the Video Screen...........................3-99
Distortion....................................................3-97
Rear Seat Entertainment System...................3-80
DVD Player....................................................3-80
E
Easy Exit Seat...............................................2-50
Electrical System
Add-On Equipment.....................................5-103
Fuses and Circuit Breakers.........................5-103
Power Windows and Other Power Options....5-103
Windshield Wiper Fuses.............................5-103
Emissions Inspection and Maintenance
Programs...................................................3-42
Engine
Air Cleaner/Filter.........................................5-18
Battery.......................................................5-39
Check and Service Engine Soon Light............3-40
Coolant......................................................5-23
Coolant Heater............................................2-21
Coolant Temperature Gage...........................3-38
Engine Compartment Overview......................5-12
Exhaust.....................................................2-30
Fan Noise..................................................5-33
Oil .............................................................5-13
Overheating................................................5-25
Starting......................................................2-19
5