2003 GMC YUKON cooling

97,500 Miles (162 500 km)
❑Check rear/front axleuid level and adduid as
needed. Check constant velocity joints and axle seals
for leaking.
❑Rotate tires. SeeTire Inspection and Rotation on
page 5-61for proper rotation pattern and additional
information.(See footnote +.)
100,000 Miles (166 000 km)
❑Inspect spark plug wires.An Emission Control
Service.
❑Replace spark plugs.An Emission Control Service.
❑Change automatic transmissionuid andlter if
the vehicle’s GVWR is over 8,600 lbs or 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.
❑If you haven’t used your vehicle under severe service
conditions listed previously and, therefore, haven’t
changed your automatic transmissionuid, change
both theuid andlter.
❑Change transfer caseuid.
❑Except 8.1L V8 Engine: Inspect Positive Crankcase
Ventilation (PCV) valve.An Emission Control
Service.
150,000 Miles (240 000 km)
❑Drain,ush and rell cooling system (or every
60 months since last service, whichever occursrst).
SeeEngine Coolant on page 5-26for what to use.
Inspect hoses. Clean radiator, condenser, pressure
cap and neck. Pressure test the cooling system
and pressure cap.An Emission Control Service.
❑Inspect engine accessory drive belt.An Emission
Control Service.
6-10
2003 - Yukon/Yukon XL

Engine Cooling System Inspection
Inspect the hoses and have them replaced if they
are cracked, swollen or deteriorated. Inspect all pipes,
ttings and clamps; replace as needed. Clean the
outside of the radiator and air conditioning condenser.
To help ensure proper operation, a pressure test of
the cooling system and pressure cap is recommended
at least once a year.
Transfer Case and Front Axle
(Four-Wheel Drive) Inspection
Every 12 months or at engine oil change intervals,
check front axle and transfer case and add lubricant
when necessary. Auid loss could indicate a problem;
check and have it repaired, if needed. On manual
shift transfer case, oil the control lever pivot point. Check
vent hose at transfer case for kinks and proper
installation. More frequent lubrication may be required
on off-road use.
Brake System Inspection
Inspect the complete system. Inspect brake lines and
hoses for proper hook-up, binding, leaks, cracks,
chang, etc. Inspect disc brake pads for wear and rotors
for surface condition. Inspect other brake parts,
including calipers, parking brake, etc. You may need to
have your brakes inspected more often if your driving
habits or conditions result in frequent braking.
6-16
2003 - Yukon/Yukon XL

Cleaning (cont.)
Underbody Maintenance...............................5-94
Video Screen............................................3-125
Weatherstrips..............................................5-91
Cleaning Aluminum or Chrome-Plated Wheels.....5-93
Cleaning Exterior Lamps/Lenses.......................5-92
Cleaning Fabric/Carpet....................................5-89
Cleaning Glass Surfaces..................................5-91
Cleaning Interior Plastic Components.................5-91
Cleaning Leather............................................5-90
Cleaning the Mirror.........................................2-43
Cleaning the Top of the Instrument Panel...........5-91
Cleaning the Windshield, Backglass and Wiper
Blades.......................................................5-93
Cleaning Tires................................................5-94
Cleaning Vinyl................................................5-90
Climate Control System...................................3-21
Dual ..........................................................3-22
Dual Automatic............................................3-26
Rear Air Conditioning and Heating System......3-33
Rear Air Conditioning and Heating System,
Electronic................................................3-35
Rear Air Conditioning System........................3-32
Compact Disc Messages................3-84, 3-97, 3-110
Compass Calibration...............................2-42, 2-44
Compass Operation.........................................2-44
Compass Variance..................................2-41, 2-44Content Theft-Deferrent....................................2-16
Control of a Vehicle.......................................... 4-6
Convenience Net............................................2-56
Coolant
Engine Temperature Gage............................3-46
Heater, Engine............................................2-21
Surge Tank Pressure Cap.............................5-29
Cooling System..............................................5-32
Cruise Control................................................3-11
Cruise Control Light........................................3-52
Cupholder(s)..................................................2-54
Current and Past Model Order Forms................7-11
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....7-10
Reporting Safety Defects to the Canadian
Government............................................7-10
Reporting Safety Defects to the United States
Government.............................................. 7-9
Roadside Assistance Program......................... 7-5
Service Publications Ordering Information........7-10
4
2003 - Yukon/Yukon XL

E
Easy Exit Seat...............................................2-60
Electrical System
Add-On Equipment......................................5-97
Fuses and Circuit Breakers...........................5-98
Power Windows and Other Power Options......5-97
Windshield Wiper Fuses...............................5-97
Electrochromic Mirror Operation................2-41, 2-43
Emissions Inspection and Maintenance
Programs...................................................3-50
Engine
Air Cleaner/Filter.........................................5-21
Battery.......................................................5-43
Check and Service Engine Soon Light............3-48
Compartment Overview................................5-12
Coolant......................................................5-26
Coolant Heater............................................2-21
Coolant Temperature Gage...........................3-46
Cooling System Inspection............................6-16
Exhaust.....................................................2-38
Fan Noise..................................................5-37
Oil .............................................................5-16
Overheating................................................5-29
Starting
......................................................2-20
ENGINE COOLANT HOT
.................................3-64
Engine Coolant Level Check
.............................6-11
Engine Hour Meter Display
...............................3-39Engine Oil Additives........................................5-19
Engine Oil Level Check...................................6-11
ENGINE OVERHEATED..................................3-65
Entering or Exiting the Third Row Seats.............. 1-8
Entertainment System
Cleaning the Video Screen..........................3-125
DVD Distortion..........................................3-123
Entry Lighting.................................................3-18
Environmental Concerns..................................4-26
Erasing HomeLink
®Buttons..............................2-53
Exit Lighting...................................................3-18
Express-Down Windows...................................2-15
Extender, Safety Belt.......................................1-43
Exterior Lamps...............................................3-14
F
Filter
Engine Air Cleaner......................................5-21
Finding a PTY Station
(RDS and XM™) .......................3-78, 3-88, 3-101
Finding a Station....................3-73, 3-76, 3-86, 3-99
Finish Care....................................................5-92
Finish Damage...............................................5-94
Fixed Mast Antenna.......................................3-125
Flash-To-Pass.................................................. 3-9
Flat Tire........................................................5-69
Flat Tire, Changing.........................................5-69
6
2003 - Yukon/Yukon XL

H
Hazard Warning Flashers................................... 3-6
Head Restraints............................................... 1-8
Headlamp High/Low-Beam Changer.................... 3-9
Headlamps....................................................5-53
Bulb Replacement.......................................5-52
Front Turn Signal, Sidemarker and Daytime
Running Lamps........................................5-54
Halogen Bulbs............................................5-53
Roof Marker Lamps.....................................5-55
Side Identification Marker Lamps...................5-55
Headphones.................................................3-117
Heated Seats................................................... 1-5
Heating.........................................................3-30
Highway Hypnosis...........................................4-44
Hill and Mountain Roads..................................4-45
Hitches..........................................................4-67
HomeLink Transmitter, Programming..................2-51
HomeLink
®Transmitter....................................2-50
Hood
Checking Things Under................................5-10
Release.....................................................5-11
Horn ............................................................... 3-7
How to Add Coolant to the Coolant Surge Tank......5-34
How to Add Fluid
............................................5-25
How to Check
........................................5-23, 5-61
How to Check Lubricant
...................................5-50How to Check Power Steering Fluid..................5-39
How to Inspect...............................................5-21
How to Use This Manual...................................... ii
How to Wear Safety Belts Properly...................1-27
Hydroplaning..................................................4-40
I
If No Steam Is Coming From Your Engine..........5-31
If Steam Is Coming From Your Engine...............5-30
If the Light is Flashing.....................................3-49
If the Light Is On Steady.................................3-49
If You Are Stuck in Sand, Mud, Ice or Snow.......4-52
If You Do Decide To Pull A Trailer.....................4-62
If You’re Caught in a Blizzard...........................4-50
Ignition Positions.............................................2-19
Ignition Transmission Lock Check......................6-14
Infants and Young Children, Restraints...............1-46
Inflation -- Tire Pressure..................................5-61
Inspection
Brake System.............................................6-16
Engine Cooling System................................6-16
Exhaust System..........................................6-15
Fuel System...............................................6-15
Part C - Periodic Maintenance.......................6-15
Steering and Suspension..............................6-15
Transfer Case and Front Axle
(Four-Wheel Drive)...................................6-16
8
2003 - Yukon/Yukon XL

Locks (cont.)
Rear Door Security Locks.............................2-11
Loss of Control...............................................4-21
LOW COOLANT LEVEL..................................3-64
Low Fuel Warning Light...................................3-53
Luggage Carrier..............................................2-55
Lumbar
Power Controls............................................. 1-5
M
Maintenance, Normal Replacement Parts..........5-109
Maintenance Schedule
At Each Fuel Fill.........................................6-11
At Least Once a Month................................6-11
At Least Once a Year..................................6-12
At Least Twice a Year..................................6-12
Brake System Inspection..............................6-16
Engine Cooling System Inspection.................6-16
Exhaust System Inspection...........................6-15
Fuel System Inspection................................6-15
How This Section is Organized....................... 6-3
Introduction.................................................. 6-2
Maintenance Requirements............................. 6-2
Part A - Scheduled Maintenance Services......... 6-4
Part B - Owner Checks and Services.............6-11
Part C - Periodic Maintenance Inspections......6-15
PartD-Recommended Fluids and
Lubricants...............................................6-17
PartE-Maintenance Record........................6-19Maintenance Schedule (cont.)
Scheduled Maintenance................................. 6-5
Steering and Suspension Inspection...............6-15
Transfer Case and Front Axle (Four-Wheel
Drive) Inspection......................................6-16
Using Your................................................... 6-4
Your Vehicle and the Environment................... 6-2
Maintenance When Trailer Towing.....................4-72
Making Turns.................................................4-70
Malfunction Indicator Light................................3-48
Manual Seats................................................... 1-3
Manual Windows............................................2-14
Matching Transmitter(s) to Your Vehicle............... 2-6
Memory Seat.................................................2-58
Message
DIC Warnings and Messages........................3-64
Mexico, Central America and Caribbean Islands/
Countries (Except Puerto Rico and U.S. Virgin
Islands)....................................................... 7-4
Mirrors
Automatic Dimming Rearview with Compass
and Temperature Display
...........................2-43
Automatic Dimming Rearview with OnStar
®,
Compass and Temperature Display
.............2-40
Manual Rearview Mirror
................................2-40
Outside Automatic Dimming Mirror
.................2-47
Outside Camper-Type Mirrors
........................2-46
Outside Convex Mirror
.................................2-48
Outside Curb View Assist Mirrors
...................2-47
Outside Heated Mirrors
................................2-48
10
2003 - Yukon/Yukon XL