2007 GMC YUKON XL warning

Brakes
Brake Fluid
Your brake master
cylinder reservoir is
lled with DOT-3 brake
uid. SeeEngine
Compartment Overview
on page 436for the
location of the reservoir.
There are only two reasons why the brake uid
level in the reservoir might go down. The rst
is that the brake uid goes down to an acceptable
level during normal brake lining wear. When
new linings are put in, the uid level goes back
up. The other reason is that uid is leaking out of
the brake system. If it is, you should have your
brake system xed, since a leak means that
sooner or later your brakes will not work well, or
will not work at all.So, it is not a good idea to top off your brake uid.
Adding brake uid will not correct a leak. If you
add uid when your linings are worn, then you will
have too much uid when you get new brake
linings. You should 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 232.
Refer to the Maintenance Schedule to determine
when to check your brake uid. SeeScheduled
Maintenance on page 555.
463

Brake Wear
Your vehicle has four-wheel 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 may 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 your 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 may cause a
brake squeal when the brakes are rst applied
or lightly applied. This does not mean something
is wrong with your 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 GM torque
specications.
Brake linings should always be replaced as
complete axle sets.
Brake Pedal Travel
See your dealer 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 of brake trouble.
Brake Adjustment
Every time you make a brake stop, your disc
brakes adjust for wear.
465

Replacing Brake System Parts
The braking system on a vehicle is complex. Its
many parts have to be of top quality and work well
together if the vehicle is to have really good
braking. Your vehicle was designed and tested
with top-quality GM brake parts. When you replace
parts of your braking system — for example,
when your brake linings wear down and you need
new ones put in — be sure you get new
approved GM replacement parts. If you do not,
your brakes may no longer work properly. For
example, if someone puts in brake linings that are
wrong for your vehicle, the balance between your
front and rear brakes can change — for the worse.
The braking performance you have come to expect
can change in many other ways if someone puts in
the wrong replacement brake parts.
Battery
Your vehicle has a maintenance free battery.
When it is time for a new battery, get one that has
the replacement number shown on the original
battery’s label. We recommend an ACDelco
®
replacement battery. SeeEngine Compartment
Overview on page 436for battery location.Warning:Battery posts, terminals, and related
accessories contain lead and lead compounds,
chemicals known to the State of California
to cause cancer and reproductive harm. Wash
hands after handling.
Vehicle Storage
If you are not going to drive your vehicle for
25 days or more, remove the black,
negative (−) cable from the battery. This will
help keep your battery from running down.
{CAUTION:
Batteries have acid that can burn you and
gas that can explode. You can be badly
hurt if you are not careful. SeeJump
Starting on page 467for tips on working
around a battery without getting hurt.
466

Remove the valve cap from the tire valve stem.
Press the tire gage rmly onto the valve to
get a pressure measurement. If the cold tire
ination pressure matches the recommended
pressure on the Tire and Loading Information
label, no further adjustment is necessary. If the
ination pressure is low, add air until you reach the
recommended amount.
If you overll the tire, release air by pushing on
the metal stem in the center of the tire valve.
Recheck the tire pressure with the tire gage.
Be sure to put the valve caps back on the valve
stems. They help prevent leaks by keeping out dirt
and moisture.Tire Pressure Monitor System
The Tire Pressure Monitor System (TPMS) uses
radio and sensor technology to check tire pressure
levels. If your vehicle has this feature, sensors
are mounted on each tire and wheel assembly,
except the spare tire. The TPMS sensors monitor
the air pressure in your vehicle’s tires and
transmit tire pressure readings to a receiver
located in the vehicle.
The TPMS is designed to alert the driver, if a low
tire pressure condition exists. If your vehicle has the
Driver Information Center (DIC), the driver may also
check tire pressure levels using the DIC.
When a low tire pressure condition is detected,
the TPMS will illuminate the low tire pressure
warning symbol located on the instrument panel
cluster. If your vehicle has the DIC feature, a
message to check the pressure in a specic tire
will also appear on the DIC display. The low
tire pressure warning symbol on the instrument
panel cluster and the CHECK TIRE PRESSURE
warning message on the DIC display will appear at
each ignition cycle until the tires are inated to
the correct ination pressure.
492

For additional information and details about the
DIC operation and displays seeDIC Operation and
Displays (With DIC Buttons) on page 244orDIC
Operation and Displays (Without DIC Buttons)
on page 251andDIC Warnings and Messages on
page 254.
You may notice, during cooler weather conditions,
that the tire pressure monitor light, located on
the instrument panel cluster, and the CHECK TIRE
PRESSURE message will appear when the
vehicle is rst started and then turn off as you
start to drive the vehicle. This could be an early
indicator that the tire pressures are getting low and
need to be inated to the proper pressure.
Each tire, including the spare (if provided), should
be checked monthly when cold and inated to
the ination pressure recommended by the vehicle
manufacturer on the vehicle placard or tire
ination pressure label. (If your vehicle has tires of
a different size than the size indicated on the
vehicle placard or tire ination pressure label, you
should determine the proper tire ination
pressure for those tires.)As an added safety
feature, your vehicle has
been equipped with a
tire pressure monitoring
system (TPMS) that
illuminates a low tire
pressure telltale when
one or more of your tires
is signicantly
under-inated.
Accordingly, when the low tire pressure telltale
illuminates, you should stop and check your tires
as soon as possible, and inate them to the
proper pressure. Driving on a signicantly
under-inated tire causes the tire to overheat and
can lead to tire failure. Under-ination also
reduces fuel efficiency and tire tread life, and may
affect the vehicle’s handling and stopping ability.
Please note that the TPMS is not a substitute
for proper tire maintenance, and it is the driver’s
responsibility to maintain correct tire pressure,
even if under-ination has not reached the level to
trigger illumination of the TPMS low tire pressure
telltale.
493

Your vehicle has also been equipped with a TPMS
malfunction indicator to indicate when the
system is not operating properly. The TPMS
malfunction indicator is combined with the low tire
pressure telltale. When the system detects a
malfunction, the telltale will ash for approximately
one minute and then remain continuously
illuminated. This sequence will continue upon
subsequent vehicle start-ups as long as the
malfunction exists.
When the malfunction indicator is illuminated, the
system may not be able to detect or signal low
tire pressure as intended. TPMS malfunctions may
occur for a variety of reasons, including the
installation of replacement or alternate tires or
wheels on the vehicle that prevent the TPMS from
functioning properly. Always check the TPMS
malfunction telltale after replacing one or more
tires or wheels on your vehicle to ensure that the
replacement or alternate tires and wheels allow
the TPMS to continue to function properly.The CHECK TIRE PRESSURE warning message
and low tire pressure light (telltale) will come
on each time the vehicle is started until the tires
are inated to the correct ination pressure.
The Tire and Loading Information label (tire
information placard) shows the size of your
vehicle’s original tires and the correct ination
pressure for your vehicle’s tires when they
are cold. SeeInation - Tire Pressure on
page 490. For the location of the tire and loading
information label, seeLoading Your Vehicle
on page 390.
Your vehicle’s TPMS can alert you about a low
tire pressure condition but it does not replace
normal tire maintenance. SeeTire Inspection and
Rotation on page 497andTires on page 482.
Notice:Do not use a tire sealant if your
vehicle has Tire Pressure Monitors. The liquid
sealant can damage the tire pressure monitor
sensors.
494

{CAUTION:
If you use bias-ply tires on your vehicle,
the wheel rim anges 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.
If you must replace your vehicle’s tires with those
that do not have a TPC Spec number, make
sure they are the same size, load range, speed
rating, and construction type (radial and
bias-belted tires) as your vehicle’s original tires.Vehicles that have a tire pressure monitoring
system may give an inaccurate low-pressure
warning if non-TPC spec rated tires are installed
on your vehicle. Non-TPC Spec rated tires
may give a low-pressure warning that is higher or
lower than the proper warning level you would
get with TPC Spec rated tires. SeeTire Pressure
Monitor System on page 492.
Your vehicle’s original equipment tires are listed
on the Tire and Loading Information Label.
This label is attached to the vehicle’s center pillar
(B-pillar). SeeLoading Your Vehicle on page 390,
for more information about the Tire and Loading
Information Label and its location on your vehicle.
501

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 specied 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 signicantly 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 specied
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.
Temperature – A, B, C
The temperature grades are A (the highest), B,
and C, representing the tire’s resistance to
the generation of heat and its ability to dissipate
heat when tested under controlled conditions on a
specied indoor laboratory test wheel. Sustained
high temperature can cause the material of the tire
to degenerate and reduce tire life, and excessive
temperature can lead to sudden tire failure.
The grade C corresponds to a level of performance
which all passenger car tires must meet under
the Federal Motor Vehicle Safety Standard
No. 109. Grades B and A represent higher levels
of performance on the laboratory test wheel
than the minimum required by law.
Warning:The temperature grade for this tire is
established for a tire that is properly inated
and not overloaded. Excessive speed,
underination, or excessive loading, either
separately or in combination, can cause heat
buildup and possible tire failure.
503