2003 GMC YUKON DENALI heater

Cooling System
When you decide it’s safe to lift the hood, here’s what
you’ll see: If the
coolant inside the coolant surge tank
is boiling,
don’t do anything else until
it cools down. The vehicle
should be parked on a level surface.
A. Coolant Surge Tank
B. Coolant Surge Tank Pressure Cap
C. Engine Fan
1
The coolant level should
be at or above the FULL
COLD mark. If
it isn’t,
you may have a leak at the
pressure cap or in the
radiator hoses, heater
hoses, radiator, water pump or somewhere else
in the cooling system.
5-28

Heater and rac.-:or hoses, and other engine
parts, can be very hot. Don’t touch them. If you
do, you can be burned.
Don’t run the engine
if there is a leak. If you
run
the engine, it could lose all coolant. That
could cause an engine fire, and you could be
burned. Get any leak fixed before you drive the
vehicle.
If there seems to be no leak, start the engine again.
The engine cooling fan speed should increase when idle
speed is doubled by pushing the accelerator pedal
down. If it doesn’t, your vehicle needs service. Turn
off
the engine.
Notice: Engine damage from running your engine
without coolant isn’t covered by your warranty.
See “Overheated Engine Protection Operating
Mode”
in the Index for information on driving to a
safe place
in an emergency.
Notice: When adding coolant, it is important that
you use only
DEX-COOL@ (silicate-free) coolant.
If coolant other than DEX-COOL@ is added to
the system, premature engine, heater core or radiator corrosion
may result. In addition, the engine
coolant will require change sooner
- at 30,000 miles
(50 000 km) or 24 months, whichever occurs first.
Damage caused by
the use of coolant other
than DEX-COOL@ is not covered by your new vehicle
warranty.
How to Add Coolant to the Coolant
Surge Tank
If you haven’t found a problem yet, check to see if
coolant is visible in the surge tank. If coolant is visible
but the coolant level isn’t at or above the
FULL
COLD mark, add a 50/50 mixture of clean, drinkable
water and
DEX-COOL@ coolant at the coolant
surge tank, but be sure the cooling system, including
the coolant surge tank pressure cap, is cool before you
do it. See Engine Coolant on
page 5-22 for more
information.
If no coolant is visible in the surge tank, add coolant as
follows:
5-29

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 wouldn't get the overheat warning.
Your engine could catch fire and you or others
could be burned. Use a
50/50 mixture of clean,
drinkable water and DEX
COOL@ coolant.
Notice: In cold weather, water can freeze and crack
the engine, radiator, heater core and other parts.
Use the recommended coolant and the proper
coolant mixture. You can be burned
if you spill coolant on tist
engine parts. Coolant contains ethylene glycol
and
it will burn if the engine parts are hot
enough. Don't
spill coolant on a hot engine.
1. Park the vehicle on a
level surface.
SURGE RESERVOIR
15 PSI
TANK - 105 kPa
D'EXPANSION I
You
can remove the coolant surge tank pressure
cap when the cooling system, including the coolant
surge tank pressure cap and upper radiator hose,
is no longer hot.
Turn the pressure cap slowly counterclockwise
(left) about one full turn. If you hear a hiss, wait for
that
to stop. A hiss means there is still some
pressure left.
5-31

Comfort Controls ............................................. 3-1 9
Compact Disc Messages
.................................. 3-71
Compass Calibration
....................................... 2-33
Compass Variance
.......................................... 2-32
Content Theft-Deterrent
......................... .... 2-16
Control of a Vehicle
......................... ......... 4-5
Convenience Net ............................................ 2-44
Coolant Engine Temperature Gage
............................ 3-36
Heater, Engine
............................................ 2-21
Surge Tank Pressure Cap
............................. 5-25
Cooling System
.............................................. 5-28
Cruise Control
................................................ 3-10
Cruise Control Light
......................... ....... 3-41
Cupholder(s)
....................................... .... 2-42
Current and Past Model Order Forms
......... 7-1 1
Customer Assistance Information Courtesy Transportation
.................................. 7-7
Customer Assistance for Text Telephone (TTY)
Users
....................................................... 7-4
Customer Assistance
Off ices ........................... 7-4
Customer Satisfaction Procedure
..................... 7-2
GM Mobility Program for Persons with
Disabilities
................................................ 7-5
Reporting Safety Defects
to General Motors .... 7-10
Reporting Safety Defects to the Canadian Government
.............................................. 7-9
Reporting Safety Defects
to the United States
Government
.............................................. 7-9
Compact
Disc Changer Errors
.......................... 3-85 Customer Assistance Information
(cont.)
Roadside Assistance Program ......................... 7-5
Service Publications Ordering Information
.... 7-10
Daytime Running Lamps
.................................. 3-14
Defensive Driving
............................................. 4-2
Defogging and Defrosting
................................. 3-24
Delayed Locking
............................................... 2-9
Doing Your Own Service Work
........................... 5-3
Dome Lamps
................................................. 3-16
Door
Delayed Locking
........................................... 2-9
Power Door Locks
......................................... 2-9
Programmable Automatic Door Locks
............. 2-10
Rear Door Security Locks
............................. 2-12
Driver Position, Safety Belt
..................................... 1-30
DRIVER DOOR AJAR
..................................... 3-56
Driver Information Center (DIC)
......................... 3-43
DIC Operation and Displays
.......................... 3-43
DIC Warnings and Messages
........................ 3-52
At Night
..................................................... 4-28
City
........................................................... 4-32
Defensive
..................................................... 4-2
Drunken
....................................................... 4-2
Locks
.......................................................... 2-8
Driving
4

Driving (cont.)
Freeway
....................... ............ 4-33
Hill and Mountain Roads
..., ................... 4-35
In Rain and on Wet Roads
....................... 4-29
winter ........................................................ 4-37
Driving On Grades .......................................... 4-54
Driving on Snow or Ice
.................................... 4-38
Driving Through Deep Standing Water
............... 4-31
Driving Through Flowing Water
......................... 4-31
DVD Driving with a Trailer
....................................... 4-53
Care
of Your ............................................... 3-88
Care
of Your DVD Player ............................. 3-89
Cleaning the Video Screen
........................... 3-89
Distortion .................................................... 3-86
Rear Seat Entertainment System
................... 3-72
DVD Player
.................................................... 3-72 Engine
Air Cleaner/Filter
......................................... 5-17
Battery
....................................................... 5-39
Check and Service Engine Soon Light
............ 3-38
Coolant ...................................................... 5-22
Coolant Heater
............................................ 2-21
Coolant Temperature Gage
........................... 3-36
Cooling System Inspection
............................ 6-14
Engine Compartment Overview
...................... 5-12
Exhaust
..................................................... 2-29
Fan Noise
.................................................. 5-33
Oil
............................................................. 5-13
Overheating
................................................ 5-25
Starting
...................................................... 2-19
Engine Air Cleaner Filter Restriction
Indicator Check
........................................... 6-11
ENGINE COOLANT HOT
................................. 3-53
Engine Coolant Level Check
............................. 6-10
Engine Oil Additives ........................................ 5-16
Engine Oil Level Check
................................... 6-10
Entering or Exiting the Third Row Seats
.............. 1-7
Engine
Oil and Chassis Lubrication Scheduled
Maintenance
................................................. 6-5
ENGINE OVERHEATED
.................................. 3-53
Entertainment System Cleaning the Video Screen
........................... 3-89
DVD Distortion
............................................ 3-86
Entry Lighting
................................................. 3-16
Erasing HomeLink@ Buttons
.............................. 2-41
E
Easy Exit Seat ............................................... 2-48
Electrical System
............................................ 5-87
Add-on Equipment
...................................... 5-87
Fuses and Circuit Breakers
........................... 5-87
Power Windows and Other Power Options
...... 5-87
Windshield Wiper Fuses
............................... 5-87
Electrochromic Mirror Operation
................ 2-32
Emissions Inspection and Maintenance
Programs
....................................... .... 3-40
5

Steering in Emergencies ................... .... 4-12
Steering Tips
.................................................. 4-1 1
Steering Wheel Controls. Audio
......................... 3-86
Stereo RCA Jacks
.......................................... 3-78
Storage Areas Center Console Storage Area
.................... 2-42
Convenience Net
..................................... 2-44
Cupholder(s)
........................................... 2-42
Glove Box
.................................................. 2-42
Luggage Carrier
.......................................... 2-42
Rear Storage Area
................................... 2-44
Storing a Flat or Spare Tire. Jack
and Tools .............................
........... 5-73
Stuck in Sand. Mud. Ice or Snow
.................. 4-41
Sun Visors ..................................................... 2-15
Sunroof
.... ...................................... 2-46
Tachometer
.................................................... 3-30
Taillamps
....................................................... 5-52
Temperature and Compass Display
.................... 2-31
Testing the Alarm
.................................... 2-17
Theft-Deterrent, Radio
.................. , ....... 3-85
Theft-Deterrent Systems
................................... 2-1 6
Content Theft-Deterrent
................................ 2-1 6
Passlock@
................................................... 2-1 7
Third Row
...................................................... 1-66
Third
Row - Lap Belt ........................ ~ ~ ....... 1-40 Throttle. Adjustable
.......................................... 2-20
Tilt Wheel
........................................................ 3-6
Tilting the
50/50 Split Bench Seat ..................... 1-13
Tire Inflation Check
......................................... 6-10
Tires
..................................................... 5-55, 5-83
Buying New Tires ........................................
5-58
Chains ....................................................... 5-62
Changing a Flat Tire
.................................... 5-63
If a Tire Goes Flat ....................................... 5-63
Inflation
-- Tire Pressure ............................... 5-55
Inspection and Rotation ................................ 5-56
Spare Tire
.................................................. 5-77
Wheel Alignment and Tire Balance
................. 5-61
Wheel Replacement
..................................... 5-61
When
It Is Time for New Tires ...................... 5-58
To Use the Engine Coolant Heater .................... 2-21
Top of the Instrument Panel
............................. 5-79
Top Strap
...................................................... 1-57
Top Strap Anchor Location
............................... 1-59
Torque Lock
................................................... 2-28
Tilting the
Full Bench Seat ............................... 1-18
Uniform Tire Quality Grading
......................... 5-59
Total Weight on Your Vehicle’s Tires
.................. 4-51
Tow/Haul Mode
............................................... 2-24
Towing Tow/Haul Mode Light
... ........................ 3-42
Recreational Vehicle
................................. 4-44
Towing a Trailer
.......................................... 4-47
Your Vehicle
............................................... 4-44
14