2003 GMC YUKON climate control

Some gasolines that are not reformulated for low
emissions may contain an octane-enhancing additive
called methylcyclopentadienyl manganese tricarbonyl
(MMT); ask the attendant where you buy gasoline
whether the fuel contains MMT. General Motors does not
recommend the use of such gasolines. Fuels containing
MMT can reduce the life of spark plugs and the
performance of the emission control system may be
affected. The malfunction indicator lamp may turn on. If
this occurs, return to your authorized GM dealer for
service.
Fuel E-85 (85% Ethanol)
The 8th digit of your vehicle identification number (VIN)
shows the code letter or number that identifies your
engine. You willfind the VIN at the top left of the
instrument panel. SeeVehicle Identification Number
(VIN) on page 5-96.
If your vehicle has the 5.3L V8 engine (VIN Code Z
only), you may use either regular unleaded gasoline or
ethanol fuel containing up to 85% ethanol (E-85);
also seeFuel on page 5-4. In all other engines, including
the 5.3L V8 (VIN Code T), use only regular unleaded
gasoline.Only vehicles that have the 5.3L V8 engine
(VIN Code Z) may use 85% ethanol fuel (E-85).
Many service stations will not have an 85% ethanol fuel
(E-85) pump available. The U. S. Department of
Energy has an alternative fuels website
(http://afdcmap.nrel.gov/nrel/) that can help youfind
E-85 fuel. Those stations that do have E-85 should have
a label indicating ethanol content. Do not use the fuel
if the ethanol content isgreaterthan 85%. Your vehicle
may not operate properly if the ethanol content is
greater than 85%.
At a minimum, E-85 should meet ASTM
Specification D 5798.
To insure quick starts in the wintertime, the E-85 fuel
must be formulated properly for your climate according
to ASTM specification D 5798. If you have trouble
starting on E-85, it may be because your E-85 fuel is
not properly formulated for your climate. If this happens,
switching to gasoline or adding gasoline to your fuel
tank may improve starting. Your vehicle is designed to
accommodate a mixture of gasoline and E-85 fuel.
For good starting and heater efficiency below 32°F
(0°C), the fuel mix in the fuel tank should contain no
more than 70% ethanol.
5-6
2003 - Yukon/Yukon XL

{CAUTION:
If you use bias-ply tires on your vehicle, the
wheel rimanges could develop cracks after
many miles of driving. A tire and/or wheel
could fail suddenly, causing a crash. Use only
radial-ply tires with the wheels on your vehicle.
Uniform Tire Quality Grading
Quality grades can be found where applicable on the
tire sidewall between tread shoulder and maximum
section width. For example:
Treadwear 200 Traction AA Temperature A
The following information relates to the system
developed by the United States National Highway
Traffic Safety Administration, which grades tires by
treadwear, traction and temperature performance. (This
applies only to vehicles sold in the United States.)
The grades are molded on the sidewalls of most
passenger car tires. The Uniform Tire Quality Grading
system does not apply to deep tread, winter-type
snow tires, space-saver or temporary use spare tires,
tires with nominal rim diameters of 10 to 12 inches
(25 to 30 cm), or to some limited-production tires.While the tires available on General Motors passenger
cars and light trucks may vary with respect to these
grades, they must also conform to federal safety
requirements and additional General Motors Tire
Performance Criteria (TPC) standards.
Treadwear
The treadwear grade is a comparative rating based on
the wear rate of the tire when tested under controlled
conditions on a specified government test course.
For example, a tire graded 150 would wear one and
a half (1.5) times as well on the government course as
a tire graded 100. The relative performance of tires
depends upon the actual conditions of their use,
however, and may depart significantly from the norm
due to variations in driving habits, service practices and
differences in road characteristics and climate.
Traction–AA, A, B, C
The traction grades, from highest to lowest, are AA, A,
B, and C. Those grades represent the tire’s ability
to stop on wet pavement as measured under controlled
conditions on specified government test surfaces of
asphalt and concrete. A tire marked C may have poor
traction performance. Warning: The traction grade
assigned to this tire is based on straight-ahead braking
traction tests, and does not include acceleration,
cornering, hydroplaning, or peak traction characteristics.
5-65
2003 - Yukon/Yukon XL

Fuses Usage
RR Wiper Rear Window Wiper Switch
SEO ACCYSpecial Equipment Option
Accessory
WS WPR Windshield Wipers
TBC ACCYTruck Body Controller
Accessory
IGN 3 Ignition, Heated Seats
Fuses Usage
4WDFour-Wheel Drive System,
Auxiliary Battery
HTR A/C Climate Control System
LOCKPower Door Lock Relay
(Lock Function)
HVAC 1Inside Rearview Mirror,
Climate Control System
L DOORDriver’s Door Harness
Connection
CRUISE Cruise Control
UNLOCKPower Door Lock Relay
(Unlock Function)
RR FOG LP Rear Fog Lamp (Export Only)
BRAKE Anti-Lock Brake System
DRIVER UNLOCKPower Door Lock Relay
(Driver’s Door Unlock
Function)
IGN 0 PCM, TCM
TBC IGN 0 Truck Body Controller
VEH CHMSLVehicle and Trailer High
Mounted Stoplamp
LT TRLR ST/TRN Left Turn Signal/Stop Trailer
LT TRNLeft Turn Signals and
Sidemarkers
5-99
2003 - Yukon/Yukon XL

Fuses Usage
VEH STOPVehicle Stoplamps, Brake
Module, Electronic Throttle
Control Module
RT TRLR ST/TRN Right Turn Signal/Stop Trailer
RT TRNRight Turn Signals and
Sidemarkers
BODY Harness Connector
DDM Driver Door Module
AUX PWR 2Rear Cargo Area Power
Outlets
LOCKS Power Door Lock System
ECCRear Electronic Climate
Control
TBC 2C Truck Body Controller
FLASH Flasher Module
CB LT DOORSLeft Power Window Circuit
Breaker
TBC 2B Truck Body Controller
TBC 2A Truck Body ControllerCenter Instrument Panel Fuse Block
The center instrument panel utility block is located
underneath the instrument panel, to the left of the
steering column.
5-100
2003 - Yukon/Yukon XL

*1—Gasoline Engine and Fuel Injection Rail #2.
*2—Gasoline Engine and Fuel Injection Rail #1.
*3—Gasoline Engine; Oxygen Sensors.
*4—Gasoline Engine; Oxygen Sensors.
*5—PCM Ignition
Fuses Usage
GLOW PLUG Not Used
CUST FEED Gasoline Accessory Power
STUD #1Auxiliary Power (Single
Battery and Diesels
Only)/Dual Battery (TP2) Do
not install fuse.
MBECMid Bussed Electrical Center
Power Feed, Front Seats,
Right Doors
BLOWER Front Climate Control Fan
LBECLeft Bussed Electrical Center,
Door Modules, Door Locks,
Auxiliary Power Outlet—Rear
Cargo Area and Instrument
Panel
STUD 2Accessory Power/Trailer
Wiring Brake Feed
ABS Anti-Lock Brakes
Fuses Usage
VSES/ECAS Vehicle Stability
IGN A Ignition Power
IGN B Ignition Power
LBEC 1Left Bussed Electrical Center,
Left Doors, Truck Body
Controller, Flasher Module
TRL PARK Parking Lamps Trailer Wiring
RR PARKRight Rear Parking and
Sidemarker Lamps
LR PARKLeft Rear Parking and
Sidemarker Lamps
PARK LP Parking Lamps Relay
STARTER Starter Relay
INTPARK Interior Lamps
STOP LP Stoplamps
TBC BATTTruck Body Controller Battery
Feed
SUNROOF Sunroof
SEO B2 Off-Road Lamps
4WSVent Solenoid
Canister/Quadrasteer Module
Power
RR HVAC Rear Climate Control
5-103
2003 - Yukon/Yukon XL

Fuses Usage
AUX PWRAuxiliary Power
Outlet—Console
IGN 1 Ignition Relay
PCM 1 Powertrain Control Module
ETC/ECMElectronic Throttle Control,
Electronic Brake Controller
IGN EInstrument Panel Cluster, Air
Conditioning Relay, Turn
Signal/Hazard Switch, Starter
Relay
RTD Ride Control
TRL B/U Backup Lamps Trailer Wiring
PCM BPowertrain Control Module,
Fuel Pump
F/PMP Fuel Pump (Relay)
B/U LPBack-up Lamps, Automatic
Transmission Shift Lock
Control System
RR DEFOG Rear Window Defogger
HDLP-HI Headlamp High Beam Relay
PRIME Not Used
SIRSupplemental Inflatable
Restraint System
FRT PARKFront Parking Lamps,
Sidemarker LampsFuses Usage
DRLDaytime Running Lamps
(Relay)
SEO IGN Rear Defog Relay
TBC IGN1 Truck Body Controller Ignition
HI HDLP-LT High Beam Headlamp-Left
LH HID Not Used
DRL Daytime Running Lamps
IPC/DICInstrument Panel
Cluster/Driver Information
Center
HVAC/ECAS Climate Control Controller
CIG LTR Cigarette Lighter
HI HDLP-RT High Beam Headlamp-Right
HDLP-LOW Headlamp Low Beam Relay
A/C COMP Air Conditioning Compressor
A/C COMPAir Conditioning Compressor
Relay
RR WPR Rear Wiper/Washer
5-104
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

D
Daytime Running Lamps..................................3-16
Defensive Driving............................................. 4-2
Defogging and Defrosting.........................3-24, 3-30
Delayed Locking............................................... 2-9
Dinghy Towing................................................4-55
Doing Your Own Service Work........................... 5-3
Dolly Towing..................................................4-57
Dome Lamps .................................................3-20
Door
Delayed Locking........................................... 2-9
Locks.......................................................... 2-7
Power Door Locks......................................... 2-8
Programmable Automatic Door Locks............... 2-9
Rear Door Security Locks.............................2-11
Driver
Position, Safety Belt.....................................1-28
DRIVER DOOR AJAR.....................................3-69
Driver Information Center (DIC).........................3-53
DIC Operation and Displays..........................3-54
DIC Warnings and Messages........................3-64
Driving
At Night
.....................................................4-37
City
...........................................................4-42Driving (cont.)
Defensive..................................................... 4-2
Drunken....................................................... 4-2
Freeway.....................................................4-43
Hill and Mountain Roads..............................4-45
In Rain and on Wet Roads...........................4-39
Winter........................................................4-47
Driving Across an Incline..................................4-33
Driving Downhill..............................................4-32
Driving in Mud, Sand, Snow or Ice....................4-35
Driving in Water..............................................4-36
Driving On Grades..........................................4-70
Driving on Off-Road Hills.................................4-28
Driving on Snow or Ice....................................4-48
Driving Through Deep Standing Water...............4-40
Driving Through Flowing Water.........................4-41
Driving Uphill..................................................4-29
Driving with a Trailer.......................................4-68
Dual Automatic Climate Control System.............3-26
Dual Climate Control System............................3-22
DVD
Cleaning the Video Screen..........................3-125
Distortion..................................................3-123
Rear Seat Entertainment System..................3-111
DVD Player..................................................3-111
5
2003 - Yukon/Yukon XL