2008 GMC ENVOY warning light

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 5-120.
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.
5-40

Tire Pressure Monitor Operation
The Tire Pressure Monitor System (TPMS) is designed
to warn the driver when a low tire pressure condition
exists. TPMS sensors are mounted onto each tire
and wheel assembly, excluding the spare tire and wheel
assembly. The TPMS sensors monitor the air pressure
in the vehicle’s tires and transmit the 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) steering wheel control
buttons, tire pressure levels may also be checked
through the DIC. See “Tire Pressures” underDIC
Operation and Displays on page 3-50.
When a low tire pressure
condition is detected, the
TPMS illuminates the
low tire pressure warning
light located on the
instrument panel cluster.At the same time a message to check the pressure in a
specic tire appears on the Driver Information Center
(DIC) display. The low tire pressure warning light
and the DIC warning message come on at each ignition
cycle until the tires are inated to the correct ination
pressure. Using the DIC, tire pressure levels can be
viewed by the driver. For additional information and
details about the DIC operation and displays seeDIC
Operation and Displays on page 3-50andDIC Warnings
and Messages on page 3-53.
The low tire pressure warning light may come on in cool
weather when the vehicle is rst started, and then
turn off as you start to drive. This could be an early
indicator that the air pressure in the tire(s) is low
and needs to be inated to the proper pressure.
A Tire and Loading Information label, attached to your
vehicle, shows the size of your vehicle’s original
equipment tires and the correct ination pressure for
your vehicle’s tires when they are cold. SeeLoading
Your Vehicle on page 4-34, for an example of the Tire
and Loading Information label and its location on
your vehicle. Also seeInflation - Tire Pressure on
page 5-64.
5-69

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 5-72andTires on page 5-57.
Notice:Liquid tire sealants could damage the Tire
Pressure Monitor System (TPMS) sensors. Sensor
damage caused by using a tire sealant is not
covered by your warranty. Do not use liquid tire
sealants.
TPMS Malfunction Light and Message
The TPMS will not function properly if one or more of the
TPMS sensors are missing or inoperable. When the
system detects a malfunction, the low tire warning light
ashes for about one minute and then stays on for the
remainder of the ignition cycle. A DIC warning message
is also displayed. The low tire warning light and DIC
warning message come on at each ignition cycle until the
problem is corrected. Some of the conditions that can
cause the malfunction light and DIC message to come
on are:
One of the road tires has been replaced with the
spare tire. The spare tire does not have a TPMS
sensor. The TPMS malfunction light and DIC
message should go off once you re-install the road
tire containing the TPMS sensor.
The TPMS sensor matching process was started but
not completed or not completed successfully after
rotating the vehicle’s tires. The DIC message and
TPMS malfunction light should go off once the TPMS
sensor matching process is performed successfully.
See “TPMS Sensor Matching Process” later in this
section.
One or more TPMS sensors are missing or
damaged. The DIC message and the TPMS
malfunction light should go off when the TPMS
sensors are installed and the sensor matching
process is performed successfully. See your
dealer/retailer for service.
Replacement tires or wheels do not match your
vehicle’s original equipment tires or wheels. Tires
and wheels other than those recommended for your
vehicle could prevent the TPMS from functioning
properly. SeeBuying New Tires on page 5-74.
Operating electronic devices or being near facilities
using radio wave frequencies similar to the TPMS
could cause the TPMS sensors to malfunction.
If the TPMS is not functioning it cannot detect or signal
a low tire condition. See your dealer/retailer for service if
the TPMS malfunction light and DIC message come on
and stay on.
5-70

TPMS Sensor Matching Process
Each TPMS sensor has a unique identication code.
Any time you rotate your vehicle’s tires or replace one or
more of the TPMS sensors, the identication codes will
need to be matched to the new tire/wheel position. The
sensors are matched to the tire/wheel positions in the
following order: driver side front tire, passenger side front
tire, passenger side rear tire, and driver side rear tire
using a TPMS diagnostic tool. See your dealer/retailer for
service.
The TPMS sensors can also be matched to each
tire/wheel position by increasing or decreasing the tire’s
air pressure. If increasing the tire’s air pressure, do not
exceed the maximum ination pressure indicated on the
tire’s sidewall.
To decrease air-pressure out of a tire you can use the
pointed end of the valve cap, a pencil-style air pressure
gage, or a key.
You have two minutes to match the rst tire/wheel
position, and ve minutes overall to match all four
tire/wheel positions. If it takes longer than two minutes, to
match the rst tire and wheel, or more than ve minutes
to match all four tire and wheel positions the matching
process stops and you need to start over.The TPMS sensor matching process is outlined below:
1. Set the parking brake.
2. Turn the ignition switch to ON/RUN with the
engine off.
3. Turn the headlamp control from off to parking lamps
four times within three seconds. A double horn chirp
will sound and the TPMS low tire warning light will
begin to ash. The double horn chirp and ashing
TPMS warning light indicate that the TPMS matching
process has started. The TPMS warning light should
continue ashing throughout the matching
procedure.
4. Start with the driver side front tire.
5. Remove the valve cap from the valve cap stem.
Activate the TPMS sensor by increasing or
decreasing the tire’s air pressure for 10 seconds,
then stop and listen for a single horn chirp. The
single horn chirp should sound within 15 seconds,
conrming that the sensor identication code has
been matched to this tire and wheel position. If you
do not hear the conrming single horn chirp, you will
need to start over with step number one.
6. Proceed to the passenger side front tire, and repeat
the procedure in Step 5.
7. Proceed to the passenger side rear tire, and repeat
the procedure in Step 5.
5-71

8. Proceed to the driver side rear tire, and repeat the
procedure in Step 5.
9. After hearing the conrming horn chirp for the
driver’s side rear tire, check to see if the TPMS
warning light is still ashing. If yes, turn the ignition
switch to LOCK/OFF to exit the sensor matching
process. If the TPMS warning light is not ashing,
the ve minute time limit has passed and you will
need to start the process over beginning with Step 1.
10. Set all four tires to the recommended air pressure
level as indicated on the Tire and Loading
Information label.
11. Put the valve caps back on the valve stems
Tire Inspection and Rotation
We recommend that you regularly inspect your
vehicle’s tires, including the spare tire, for signs of
wear or damage. SeeWhen It Is Time for New
Tires on page 5-73for more information.
Tires should be rotated every 5,000 to 8,000 miles
(8 000 to 13 000 km). SeeScheduled Maintenance
on page 6-4.
The purpose of a regular tire rotation is to achieve
a uniform wear for all tires on the vehicle. This will
ensure that your vehicle continues to perform most
like it did when the tires were new.Any time you notice unusual wear, rotate your
tires as soon as possible and check wheel
alignment. Also check for damaged tires or wheels.
SeeWhen It Is Time for New Tires on page 5-73
andWheel Replacement on page 5-78.
When rotating your tires, always use the correct
rotation pattern shown here.
After the tires have been rotated, adjust the
front and rear ination pressures as shown on
the Tire and Loading Information label. See
Inflation - Tire Pressure on page 5-64and
Loading Your Vehicle on page 4-34.
5-72

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 (NHTSA), 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 (UTQG)
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 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.
5-77

When you go to your dealer/retailer for your service
needs, you will know that trained and supported service
technicians will perform the work using genuine parts.
If you want to purchase service information, seeService
Publications Ordering Information on page 7-16.
Owner Checks and Services on page 6-9tells you what
should be checked, when to check it, and what you can
easily do to help keep your vehicle in good condition.
The proper replacement parts, uids, and lubricants to
use are listed inRecommended Fluids and Lubricants
on page 6-12andMaintenance Replacement Parts
on page 6-14. When your vehicle is serviced, make sure
these are used. All parts should be replaced and all
necessary repairs done before you or anyone else
drives the vehicle. We recommend the use of genuine
parts from your dealer/retailer.
Scheduled Maintenance
When the change engine oil light or CHANGE ENGINE
OIL DIC message comes on, it means that service is
required for your vehicle. SeeChange Engine Oil Light
on page 3-45orDIC Warnings and Messages on
page 3-53. Have your vehicle serviced as soon as
possible within the next 600 miles (1 000 km). It
is possible that, if you are driving under the best
conditions, the engine oil life system may not indicate
that vehicle service is necessary for over a year.However, your engine oil and lter must be changed at
least once a year and at this time the system must
be reset. Your dealer/retailer has trained service
technicians who will perform this work using genuine
parts and reset the system.
If the engine oil life system is ever reset accidentally, you
must service your vehicle within 3,000 miles (5 000 km)
since your last service. Remember to reset the oil life
system whenever the oil is changed. SeeEngine Oil Life
System on page 5-19for information on the Engine Oil
Life System and resetting the system.
When the change engine oil light or CHANGE ENGINE
OIL DIC message appears, certain services, checks,
and inspections are required. Required services
are described in the following for “MaintenanceI” and
“MaintenanceII.” Generally, it is recommended that your
rst service be MaintenanceI, your second service be
MaintenanceII, and that you alternate MaintenanceI
and MaintenanceIIthereafter. However, in some cases,
MaintenanceIImay be required more often.
MaintenanceI— Use MaintenanceIif the light or
message comes on within 10 months since the vehicle
was purchased or MaintenanceIIwas performed.
MaintenanceII— Use MaintenanceIIif the previous
service performed was MaintenanceI. Always use
MaintenanceIIwhenever the light or message comes
on 10 months or more since the last service or if the light
or message has not come on at all for one year.
6-4

A
Accessories and Modications............................ 5-3
Adding a Snow Plow or Similar Equipment.........4-40
Adding Equipment to Your
Airbag-Equipped Vehicle...............................1-66
Additives, Fuel................................................. 5-7
Add-On Electrical Equipment...........................5-109
Adjustable Throttle and Brake Pedal..................2-24
Air Cleaner/Filter, Engine.................................5-21
Air Conditioning......................................3-21, 3-23
Airbag
Passenger Status Indicator...........................3-34
Readiness Light..........................................3-33
Airbag System................................................1-53
What Will You See After an Airbag Inates?....1-60
When Should an Airbag Inate?....................1-58
Where Are the Airbags?...............................1-56
Airbag Systems
Adding Equipment to Your
Airbag-Equipped Vehicle............................1-66
How Does an Airbag Restrain?......................1-59
Passenger Sensing System...........................1-61
Servicing Your Airbag-Equipped Vehicle..........1-66
What Makes an Airbag Inate?......................1-59
Antenna, Fixed Mast......................................3-103Antenna, XM™ Satellite Radio
Antenna System........................................3-103
Antilock Brake System (ABS)............................. 4-4
Antilock Brake, System Warning Light................3-39
Appearance Care
Aluminum Wheels......................................5-105
Care of Safety Belts...................................5-103
Chemical Paint Spotting..............................5-106
Cleaning Exterior Lamps/Lenses..................5-104
Fabric/Carpet............................................5-101
Finish Care...............................................5-104
Finish Damage..........................................5-106
Instrument Panel, Vinyl, and
Other Plastic Surfaces.............................5-102
Interior Cleaning........................................5-100
Leather....................................................5-102
Sheet Metal Damage..................................5-106
Tires........................................................5-106
Underbody Maintenance.............................5-106
Vehicle Care/Appearance Materials...............5-107
Washing Your Vehicle.................................5-103
Weatherstrips............................................5-103
Windshield, Backglass, and Wiper Blades......5-105
Appointments, Scheduling Service.....................7-10
Ashtray.........................................................3-20
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