2008 GMC YUKON XL brake light

*The fuses for these two circuits are installed in the
underhood electrical center, but the wires are not
connected. They should be connected by your
dealer/retailer or a qualied service center.
If you are charging a remote (non-vehicle) battery, press
the tow/haul mode button located at the end of the
shift lever. This will boost the vehicle system voltage and
properly charge the battery. If the trailer is too light for
tow/haul mode, you can turn on the headlamps as
a second way to boost the vehicle system and charge
the battery.
Electric Brake Control Wiring
Provisions
These wiring provisions are included with your vehicle
as part of the trailer wiring package. These provisions
are for an electric brake controller. The instrument panel
contains blunt cut wires near the data link connector
for the trailer brake controller. The harness contains the
following wires:
Dark Blue: Brake Signal to Trailer Connector
Red/Black: Battery
Light Blue/White: Brake Switch
White: Ground
It should be installed by your dealer/retailer or a
qualied service center.
Power Winches
If you wish to use a power winch on your vehicle, only
use it when your vehicle is stationary or anchored.
Trailer Recommendations
You must subtract your hitch loads from the Cargo
Weight Rating (CWR) for your vehicle. CWR is the
maximum weight of the load your vehicle can carry. It
doesn’t include the weight of the people inside. But you
can gure about 150 lbs. (68 kg) for each seat. The total
cargo load must not be more than your vehicle’s CWR.
Weigh your vehicle with the trailer attached, so that you
won’t go over the GVWR or GAWR. If you are using
a weight-distributing hitch, weigh the vehicle without the
spring bars in place.
You’ll get the best performance if you spread out the
weight of your load the right way, and if you choose the
correct hitch and trailer brakes.
For more information, seeTowing a Trailer on
page 4-49.
4-63

It is not a good idea to top off the brake uid. Adding
brake uid will not correct a leak. If uid is added when
the linings are worn, there will be too much uid
when new brake linings are installed. Add or remove
brake uid, as necessary, only when work is done on the
brake hydraulic system.
{CAUTION:
If you have too much brake uid, it can spill on
the engine. The uid will burn if the engine is
hot enough. You or others could be burned,
and your vehicle could be damaged. Add brake
uid only when work is done on the brake
hydraulic system. See “Checking Brake Fluid”
in this section.
When the brake uid falls to a low level, the brake
warning light will come on. SeeBrake System Warning
Light on page 3-44.
Refer to the Maintenance Schedule to determine when
to check the brake uid. SeeScheduled Maintenance
on page 6-4.
Checking Brake Fluid
The brake uid can be checked without taking off the
cap by looking at the brake uid reservoir.
The uid level should be
above MIN. If it is not,
have the brake hydraulic
system checked to
see if there is a leak.
After work is done on the brake hydraulic system,
make sure the level is above the MIN but not over
the MAX mark.
5-42

Brake Wear
Your vehicle has disc brakes. Disc brake pads have
built-in wear indicators that make a high-pitched warning
sound when the brake pads are worn and new pads
are needed. The sound can come and go or be heard all
the time your vehicle is moving, except when you are
pushing on the brake pedal rmly.
{CAUTION:
The brake wear warning sound means that
soon the brakes will not work well. That could
lead to an accident. When you hear the brake
wear warning sound, have your vehicle
serviced.
Notice:Continuing to drive with worn-out brake
pads could result in costly brake repair.
Some driving conditions or climates can cause a brake
squeal when the brakes are rst applied or lightly
applied. This does not mean something is wrong with
the brakes.Properly torqued wheel nuts are necessary to help
prevent brake pulsation. When tires are rotated, inspect
brake pads for wear and evenly tighten wheel nuts in
the proper sequence to torque specications in
Capacities and Specifications on page 5-124.
Brake linings should always be replaced as complete
axle sets.
Brake Pedal Travel
See your dealer/retailer if the brake pedal does not
return to normal height, or if there is a rapid increase in
pedal travel. This could be a sign that brake service
might be required.
Brake Adjustment
Every time you make a brake stop, the disc brakes
adjust for wear.
5-44

Trying to start your vehicle by pushing or pulling it
will not work, and it could damage your vehicle.
1. Check the other vehicle. It must have a 12-volt
battery with a negative ground system.
Notice:If the other vehicle’s system is not a 12-volt
system with a negative ground, both vehicles can
be damaged. Only use vehicles with 12-volt systems
with negative grounds to jump start your vehicle.
2. Get the vehicles close enough so the jumper cables
can reach, but be sure the vehicles are not touching
each other. If they are, it could cause a ground
connection you do not want. You would not be able
to start your vehicle, and the bad grounding
could damage the electrical systems.To avoid the possibility of the vehicles rolling, set the
parking brake rmly on both vehicles involved in the
jump start procedure. Put the automatic transmission
in PARK (P) or a manual transmission in NEUTRAL
before setting the parking brake. If you have a
four-wheel-drive vehicle, be sure the transfer case is
in a drive gear, not in NEUTRAL.
Notice:If you leave your radio or other accessories
on during the jump starting procedure, they could
be damaged. The repairs would not be covered
by your warranty. Always turn off your radio and
other accessories when jump starting your vehicle.
3. Turn off the ignition on both vehicles. Unplug
unnecessary accessories plugged into the cigarette
lighter or the accessory power outlets. Turn off
the radio and all the lamps that are not needed. This
avoids sparks and helps save both batteries. And
it could save the radio!
5-47

A
Accessories and Modications............................ 5-3
Adding a Snow Plow or Similar Equipment.........4-41
Adding Equipment to Your Airbag-Equipped
Vehicle.......................................................1-90
Additives, Fuel................................................. 5-6
Add-On Electrical Equipment...........................5-117
Adjustable Throttle and Brake Pedal..................2-29
Air Cleaner/Filter, Engine.................................5-19
Air Conditioning......................................3-23, 3-26
Airbag
Passenger Status Indicator...........................3-41
Readiness Light..........................................3-40
Airbag System................................................1-76
What Will You See After an Airbag Inates?....1-84
When Should an Airbag Inate?....................1-81
Where Are the Airbags?...............................1-78
Airbag Systems
Adding Equipment to Your Airbag-Equipped
Vehicle...................................................1-90
How Does an Airbag Restrain?......................1-83
Passenger Sensing System...........................1-85
Servicing Your Airbag-Equipped Vehicle..........1-90
What Makes an Airbag Inate?......................1-83
Antenna, Rear Side Window...........................3-130
Antenna, XM™ Satellite Radio Antenna
System.....................................................3-130Antilock Brake System (ABS)............................. 4-5
Antilock Brake, System Warning Light................3-46
Appearance Care
Aluminum or Chrome-Plated Wheels.............5-113
Care of Safety Belts...................................5-111
Chemical Paint Spotting..............................5-115
Cleaning Exterior Lamps/Lenses..................5-112
Fabric/Carpet............................................5-109
Finish Care...............................................5-112
Finish Damage..........................................5-114
Instrument Panel, Vinyl, and Other Plastic
Surfaces...............................................5-110
Interior Cleaning........................................5-108
Leather
....................................................5-110
Sheet Metal Damage..................................5-114
Tires........................................................5-114
Underbody Maintenance.............................5-114
Vehicle Care/Appearance Materials...............5-115
Washing Your Vehicle.................................5-111
Weatherstrips............................................5-111
Windshield, Backglass, and Wiper Blades......5-113
Appointments, Scheduling Service....................... 7-9
Ashtray.........................................................3-23
Audio System.................................................3-81
Audio Steering Wheel Controls....................3-128
Navigation/Radio System, see Navigation
Manual.................................................3-114
Radio Reception........................................3-129
1

Audio System (cont.)
Rear Seat Audio (RSA)...............................3-125
Setting the Clock.........................................3-82
Theft-Deterrent Feature...............................3-127
XM™ Satellite Radio Antenna System...........3-130
Audio System(s).............................................3-84
Rear Side Window Antenna.........................3-130
Automatic Headlamp System............................3-18
Automatic Transmission
Fluid..................................................5-22, 5-24
Operation...................................................2-31
Autoride
®.......................................................4-49
Auxiliary Roof Mounted Lamp Switch.................3-19
B
Battery..........................................................5-45
Electric Power Management..........................3-21
Run-Down Protection...................................3-22
Bench Seat, Split (60/40).................................1-12
Brake
Emergencies................................................ 4-6
Brakes..........................................................5-41
System Warning Light..................................3-44
Braking........................................................... 4-4
Braking in Emergencies..................................... 4-6
Break-In, New Vehicle.....................................2-26
Bucket Seats, Rear.........................................1-18Bulb Replacement...........................................5-59
Halogen Bulbs............................................5-59
Headlamp Aiming........................................5-56
License Plate Lamps....................................5-61
Replacement Bulbs......................................5-61
Taillamps, Turn Signal, Stoplamps and
Back-up Lamps........................................5-60
Buying New Tires...........................................5-80
C
Calibration.............................................2-49, 2-52
California Fuel.................................................. 5-6
California Perchlorate Materials Requirements....... 5-4
California Proposition 65 Warning....................... 5-4
Canadian Owners................................................ ii
Capacities and Specications..........................5-124
Carbon Monoxide...........2-13, 2-15, 2-47, 4-30, 4-49
Care of
Safety Belts..............................................5-110
Cargo Cover..................................................2-73
CD, MP3 ............................................3-103, 3-108
Center Console Storage Area...........................2-71
Center Seat...................................................1-11
Chains, Tire...................................................5-86
Charging System Light....................................3-43
Check
Engine Light...............................................3-48
Checking Things Under the Hood......................5-12
2

K
Keyless Entry System....................................... 2-4
Keys............................................................... 2-3
L
Labeling, Tire Sidewall.....................................5-65
Lamps
Auxiliary Roof Mounted Lamp........................3-19
Dome........................................................3-20
Dome Lamp Override...................................3-20
Reading.....................................................3-21
Lap Belt........................................................1-49
Lap-Shoulder Belt...........................................1-43
LATCH System
Child Restraints...........................................1-61
Level Control..................................................4-48
License Plate Lamps.......................................5-61
Liftgate, Power...............................................2-15
Liftgate/Liftglass..............................................2-13
Liftglass/Liftgate..............................................2-13
Light
Airbag Readiness........................................3-40
Antilock Brake System Warning.....................3-46
Brake System Warning.................................3-44
Charging System.........................................3-43
Cruise Control.............................................3-53
Fog Lamp..................................................3-53
Highbeam On.............................................3-53Light (cont.)
Low Fuel Warning.......................................3-55
Malfunction Indicator....................................3-48
Oil Pressure...............................................3-52
Passenger Airbag Status Indicator..................3-41
Safety Belt Reminders..................................3-39
Security.....................................................3-52
StabiliTrak®Indicator....................................3-46
Tire Pressure..............................................3-47
Tow/Haul Mode...........................................3-53
Lighting
Entry.........................................................3-20
Exit...........................................................3-20
Lights
Exterior Lamps............................................3-16
Flash-to-Pass............................................... 3-9
High/Low Beam Changer................................ 3-9
On Reminder..............................................3-17
Loading Your Vehicle.......................................4-35
Locking Rear Axle............................................ 4-6
Lockout Protection..........................................2-12
Locks
Delayed Locking..........................................2-11
Door..........................................................2-10
Lockout Protection.......................................2-12
Power Door................................................2-11
Programmable Automatic Door Locks.............2-11
Rear Door Security Locks.............................2-12
Loss of Control...............................................4-12
Low Fuel Warning Light...................................3-55
7

O
Odometer......................................................3-39
Odometer, Trip...............................................3-39
Off-Road Driving.............................................4-13
Off-Road Recovery..........................................4-11
Oil
Engine.......................................................5-15
Pressure Gage............................................3-51
Pressure Light.............................................3-52
Oil, Engine Oil Life System..............................5-18
Older Children, Restraints................................1-51
Online Owner Center........................................ 7-4
OnStar, Privacy..............................................7-17
OnStar
®System, see OnStar®Manual...............2-60
Operation, Universal Home Remote System........2-64
Other Warning Devices...................................... 3-6
Outlet Adjustment............................................3-33
Outlets
Accessory Power.........................................3-22
Outside
Automatic Dimming Mirror.............................2-57
Convex Mirror.............................................2-57
Heated Mirrors............................................2-57
Manual Mirrors............................................2-54
Power Foldaway Mirrors...............................2-56
Power Mirrors.............................................2-55
Trailer-Tow Mirrors.......................................2-54Overheated Engine Protection
Operating Mode..........................................5-33
Owner Checks and Services.............................. 6-9
Owners, Canadian............................................... ii
P
Paint, Damage..............................................5-114
Park Aid........................................................2-58
Park Brake....................................................2-43
Park (P)
Shifting Into................................................2-44
Shifting Out of............................................2-46
Park Tilt Mirrors..............................................2-57
Parking
Assist........................................................2-58
Over Things That Burn.................................2-46
Passenger Airbag Status Indicator.....................3-41
Passenger Sensing System..............................1-85
Passing.........................................................4-11
PASS-Key
®III+..............................................2-24
PASS-Key®III+ Operation................................2-24
Perchlorate Materials Requirements, California...... 5-4
Power
Door Locks.................................................2-11
Electrical System.......................................5-117
Liftgate......................................................2-15
Lumbar Controls........................................... 1-4
Retained Accessory (RAP)............................2-27
9