Page 452 of 520

Fuses and Circuit Breakers
The wiring circuits in your vehicle are protected from
short circuits by a combination of fuses, circuit breakers
and fusible thermal links. This greatly reduces the
chance offires caused by electrical problems.
Look at the silver-colored band inside the fuse. If the
band is broken or melted, replace the fuse. Be sure you
replace a bad fuse with a new one of the identical
size and rating.
If you ever have a problem on the road and don’t have
a spare fuse, you can borrow one that has the same
amperage. Just pick some feature of your vehicle
that you can get along without–like the radio or
cigarette lighter–and use its fuse, if it is the correct
amperage. Replace it as soon as you can.
Instrument Panel Fuse Block
The fuse block access
door is on the driver’s side
edge of the instrument
panel. Pull off the cover to
access the fuse block.
To remove fuses, hold the end of the fuse between your
thumb and indexfinger and pull straight out.
You may have spare fuses located behind the fuse
block access door. These can be used to replace a bad
fuse. However, make sure it is of the correct amperage.
5-98
2003 - Yukon/Yukon XL
Page 455 of 520
Device Usage
SEO Special Equipment Option
TRAILER Trailer Brake Wiring
UPFIT Upfitter (Not Used)
SL RIDERide Control Harness
Connection
HDLR 2 Headliner Wiring Connector
BODY Body Wiring Connector
DEFOG Rear Defogger Relay
HDLNR 1 Headliner Wiring Connector 1
SPARE RELAY Not Used
CB SEATDriver and Passenger Seat
Module Circuit Breaker
CB RT DOORRight Power Window Circuit
Breaker
SPARE Not Used
INFOInfotainment Harness
ConnectionUnderhood Fuse Block
The underhood fuse block in the engine compartment
on the driver’s side of the vehicle near the battery.
Lift the cover for access to the fuse/relay block.
To remove fuses, hold the end of the fuse between your
thumb and indexfinger and pull straight out.
5-101
2003 - Yukon/Yukon XL
Page 457 of 520

*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
Page 458 of 520

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
Page 512 of 520

Theft-Deterrent Systems (cont.)
Content Theft-Deterrent................................2-16
Passlock
®...................................................2-18
Third Row......................................................1-64
Throttle, Adjustable..........................................2-21
Tilt Wheel........................................................ 3-7
Tilting the 50/50 Split Bench Seat.....................1-12
Tilting the Bench Seat.....................................1-16
Tire Inflation Check.........................................6-11
Tires.............................................................5-60
Buying New Tires........................................5-64
Chains.......................................................5-68
Changing a Flat Tire....................................5-69
If a Tire Goes Flat.......................................5-69
Inflation -- Tire Pressure...............................5-61
Inspection and Rotation................................5-61
Spare Tire..................................................5-88
Uniform Tire Quality Grading.........................5-65
Wheel Alignment and Tire Balance.................5-66
Wheel Replacement.....................................5-66
When It Is Time for New Tires......................5-63
To Use the Engine Coolant Heater....................2-22
Top Strap......................................................1-54
Top Strap Anchor Location...............................1-55
Torque Lock...................................................2-37
Total Weight on Your Vehicle’s Tires..................4-66
Tow/Haul Mode ...............................................2-25Tow/Haul Mode Light.......................................3-52
Towing
Recreational Vehicle.....................................4-55
Towing a Trailer..........................................4-61
Your Vehicle...............................................4-54
Traction
Assist System (TAS)....................................4-10
Off Light.....................................................3-45
Stabilitrak
®System......................................4-12
TRACTION ACTIVE........................................3-68
Traction Control Operation................................4-13
Trailer
Recommendations
.......................................4-60
Trailer Brakes
.................................................4-68
Trailer Wiring Harness
.....................................4-72
Transfer Case
........................................5-49, 5-51
Transfer Case and Front Axle (Four-Wheel Drive)
Inspection
...................................................6-16
Transmission
Fluid, Automatic
...........................................5-23
Temperature Gage
.......................................3-46
TRANSMISSION HOT
.....................................3-68
Transmission Operation, Automatic
....................2-22
Transmission, Transaxle, Transfer Case Unit
Repair Manual
............................................7-10
Transportation Options
...................................... 7-8
16
2003 - Yukon/Yukon XL