change time GMC ENVOY DENALI 2008 Owner's Manual

Trailering is different than just driving your vehicle by
itself. Trailering means changes in acceleration, braking,
handling, durability and fuel economy. Successful,
safe trailering takes correct equipment, and it has to
be used properly.
That’s the reason for this part. In it are many
time-tested, important trailering tips and safety rules.
Many of these are important for your safety and that of
your passengers. So please read this section carefully
before you pull a trailer.
If You Do Decide To Pull A Trailer
If you do, here are some important points:
There are many different laws, including speed limit
restrictions, having to do with trailering. Make sure
your rig will be legal, not only where you live but also
where you’ll be driving. A good source for this
information can be state or provincial police.
Consider using a sway control. See “Hitches” later in
this section.
Don’t tow a trailer at all during the rst 500 miles
(800 km) your new vehicle is driven. Your engine,
axle or other parts could be damaged.
Then, during the rst 500 miles (800 km) that you tow
a trailer, don’t drive over 50 mph (80 km/h) and don’t
make starts at full throttle. This helps your engine
and other parts of your vehicle wear in at the heavier
loads.
You can tow in DRIVE (D). You may want to shift the
transmission to THIRD (3) or, if necessary, a lower
gear selection if the transmission shifts too often
(e.g., under heavy loads and/or hilly conditions).
Three important considerations have to do with weight:
the weight of the trailer,
the weight of the trailer tongue
and the weight on your vehicle’s tires.
Weight of the Trailer
How heavy can a trailer safely be?
It depends on how you plan to use your rig. For example,
speed, altitude, road grades, outside temperature and
how much your vehicle is used to pull a trailer are all
important. It can also depend on any special equipment
that you have on your vehicle, and the amount of tongue
weight the vehicle can carry. See “Weight of the Trailer
Tongue” later in this section for more information.
4-46

Look for this information on the oil container, and
use only those oils that are identied as meeting
GM Standard GM6094M and have the starburst
symbol on the front of the oil container.
Notice:Use only engine oil identied as meeting
GM Standard GM6094M and showing the American
Petroleum Institute Certied For Gasoline Engines
starburst symbol. Failure to use the recommended
oil can result in engine damage not covered by
your warranty.
If you are in an area of extreme cold, where the
temperature falls below−20°F (−29°C), it is
recommended that you use either an SAE 5W-30
synthetic oil or an SAE 0W-30 oil. Both provide easier
cold starting and better protection for the engine at
extremely low temperatures.
Engine Oil Additives
Do not add anything to the oil. The recommended oils
with the starburst symbol that meet GM Standard
GM6094M are all you need for good performance
and engine protection.
Engine Oil Life System
When to Change Engine Oil
Your vehicle has a computer system that lets you know
when to change the engine oil and lter. This is based
on engine revolutions and engine temperature, and not
on mileage. Based on driving conditions, the mileage
at which an oil change will be indicated can vary
considerably. For the oil life system to work properly, you
must reset the system every time the oil is changed.
When the system has calculated that oil life has been
diminished, it will indicate that an oil change is necessary.
A change engine oil light will come on, and, if your vehicle
has a Driver Information Center (DIC), a CHANGE
ENGINE OIL message will come on. See the oil as soon
as possible within the next 600 miles (1 000 km).
5-19

It is possible that, if you are driving under the best
conditions, the oil life system might not indicate that an oil
change is necessary for over a year. However, the 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 people who will perform this work using
genuine parts and reset the system. It is also important to
check the oil regularly and keep it at the proper level.
If the system is ever reset accidentally, you must
change the oil at 3,000 miles (5 000 km) since the last oil
change. Remember to reset the oil life system whenever
the oil is changed.
How to Reset the Engine Oil Life
System
The Engine Oil Life System calculates when to change
the engine oil and lter based on vehicle use.
Whenever the oil is changed, reset the system so it can
calculate when the next oil change is required. If a
situation occurs where you change the oil prior
to a change engine oil light or CHANGE ENGINE OIL
message being turned on, reset the system.To reset the Engine Oil Life System:
1. Turn the ignition key to ON/RUN with the
engine off.
2. Fully press and release the accelerator pedal slowly
three times within ve seconds.
The change engine oil light will ash while the
system is resetting.
3. When the light stops ashing, turn the key to
LOCK/OFF.
If the light/message comes back on when you start the
vehicle, the engine oil life system has not reset.
Repeat the procedure.
5-20

Automatic Transmission Fluid
When to Check and Change Automatic
Transmission Fluid
A good time to check your automatic transmission uid
level is when the engine oil is changed.
Change the uid and lter at the intervals listed in
Additional Required Services on page 6-6, and be sure
to use the transmission uid listed inRecommended
Fluids and Lubricants on page 6-12.
How to Check Automatic Transmission
Fluid
Because this operation can be a little difficult, you may
choose to have this done at the dealer/retailer service
department.
If you do it yourself, be sure to follow all the instructions
here, or you could get a false reading on the dipstick.
Notice:Too much or too little uid can damage
your transmission. Too much can mean that some
of the uid could come out and fall on hot engine
parts or exhaust system parts, starting a re. Too
little uid could cause the transmission to overheat.
Be sure to get an accurate reading if you check your
transmission uid.Wait at least 30 minutes before checking the
transmission uid level if you have been driving:
When outside temperatures are above 90°F (32°C).
At high speed for quite a while.
In heavy traffic — especially in hot weather.
While pulling a trailer.
To get the right reading, the uid should be at normal
operating temperature, which is 180°F to 200°F
(82°C to 93°C).
Get the vehicle warmed up by driving about 15 miles
(24 km) when outside temperatures are above 50°F
(10°C). If it is colder than 50°F (10°C), drive the vehicle
in THIRD (3) until the engine temperature gage moves
and then remains steady for 10 minutes.
A cold uid check can be made after the vehicle has
been sitting for eight hours or more with the engine off,
but this is used only as a reference. Let the engine
run at idle for ve minutes if outside temperatures are
50°F (10°C) or more. If it is colder than 50°F (10°C), you
may have to idle the engine longer. Should the uid
level be low during this cold check, you must check the
uid hot before adding uid. Checking the uid hot will
give you a more accurate reading of the uid level.
5-23

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 brake parts.
When you replace parts of the braking system — for
example, when the brake linings wear down and you
need new ones put in — be sure you get new approved
replacement parts. If you do not, the brakes might not
work properly. For example, if someone puts in brake
linings that are wrong for your vehicle, the balance
between the 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, see your dealer/retailer for
one that has the replacement number shown on the
original battery’s label. SeeEngine Compartment
Overview on page 5-12for 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
{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 5-42for tips on working around a battery
without getting hurt.
Infrequent Usage: If you drive your vehicle infrequently,
remove the black, negative (−) cable from the battery.
This will help keep the battery from running down.
Extended Storage: For extended storage of your vehicle,
remove the black, negative (−) cable from the battery
or use a battery trickle charger. This will help maintain
the charge of the battery over an extended period
of time.
5-41

Reset the Tire Pressure Monitor System. SeeTire
Pressure Monitor Operation on page 5-69.
Make certain that all wheel nuts are properly
tightened. See “Wheel Nut Torque” under
Capacities and Specifications on page 5-120.
{CAUTION:
Rust or dirt on a wheel, or on the parts to
which it is fastened, can make wheel nuts
become loose after time. The wheel could
come off and cause an accident. When
you change a wheel, remove any rust or
dirt from places where the wheel attaches
to the vehicle. In an emergency, you can
use a cloth or a paper towel to do this;
but be sure to use a scraper or wire brush
later, if needed, to get all the rust or dirt
off. SeeChanging a Flat Tire on page 5-82.
Make sure the spare tire is stored securely. Push,
pull, and then try to rotate or turn the tire. If it
moves, tighten the cable. SeeStoring a Flat or
Spare Tire and Tools on page 5-96.
When It Is Time for New Tires
Various factors, such as maintenance, temperatures,
driving speeds, vehicle loading, and road conditions,
inuence when you need new tires.
One way to tell when it is
time for new tires is to
check the treadwear
indicators, which appear
when your tires have only
1/16 inch (1.6 mm) or less
of tread remaining. Some
commercial truck tires may
not have treadwear
indicators.
5-73

8. Remove all the wheel
nuts and the at tire.
{CAUTION:
Rust or dirt on a wheel, or on the parts to
which it is fastened, can make wheel nuts
become loose after time. The wheel could come
off and cause an accident. When you change a
wheel, remove any rust or dirt from places
CAUTION: (Continued)
CAUTION: (Continued)
where the wheel attaches to the vehicle. In an
emergency, you can use a cloth or a paper
towel to do this; but be sure to use a scraper
or wire brush later, if needed, to get all the
rust or dirt off. SeeChanging a Flat Tire on
page 5-82.
9. Remove any rust or dirt
from the wheel bolts,
mounting surfaces
and spare wheel.
5-89

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

Calling For Assistance
For prompt and efficient assistance when calling, please
provide the following to the Roadside Assistance
Representative:
Your name, home address, and home telephone
number
Telephone number of your location
Location of the vehicle.
Model, year, color, and license plate number of the
vehicle
Odometer reading, Vehicle Identication
Number (VIN), and delivery date of the vehicle
Description of the problem
Towing and Road Service Exclusions
Specically excluded from Roadside Assistance
coverage are towing or services for vehicles operated
on a non-public roadway or highway, nes, impound
towing caused by a violation of local, Municipal, State,
Provincial, or Federal law, and mounting, dismounting
or changing of snow tires, chains, or other traction
devices.Roadside Assistance is not part of or included in the
coverage provided by the New Vehicle Limited Warranty.
GMC and General Motors of Canada Limited reserve
the right to make any changes or discontinue the
Roadside Assistance program at any time without
notication.
Scheduling Service Appointments
When your vehicle requires warranty service, contact
your dealer/retailer and request an appointment.
By scheduling a service appointment and advising your
service consultant of your transportation needs, your
dealer/retailer can help minimize your inconvenience.
If your vehicle cannot be scheduled into the service
department immediately, keep driving it until it can be
scheduled for service, unless, of course, the problem is
safety-related. If it is, please call your dealership/retailer,
let them know this, and ask for instructions.
If the dealer/retailer requests that you simply drop the
vehicle off for service, you are urged to do so as early in
the work day as possible to allow for the same day repair.
7-10

Courtesy Rental Vehicle
Your dealer may arrange to provide you with a courtesy
rental vehicle or reimburse you for a rental vehicle
that you obtain if your vehicle is kept for an overnight
warranty repair. Rental reimbursement will be limited
and must be supported by original receipts. This
requires that you sign and complete a rental agreement
and meet state/provincial, local, and rental vehicle
provider requirements. Requirements vary and may
include minimum age requirements, insurance coverage,
credit card, etc. You are responsible for fuel usage
charges and may also be responsible for taxes, levies,
usage fees, excessive mileage, or rental usage
beyond the completion of the repair.
It may not be possible to provide a like-vehicle as a
courtesy rental.
Additional Program Information
All program options, such as shuttle service, may not be
available at every dealer. Please contact your dealer
for specic information about availability. All Courtesy
Transportation arrangements will be administered
by appropriate dealer personnel.
General Motors reserves the right to unilaterally modify,
change or discontinue Courtesy Transportation at
any time and to resolve all questions of claim eligibility
pursuant to the terms and conditions described
herein at its sole discretion.
Collision Damage Repair
If your vehicle is involved in a collision and it is damaged,
have the damage repaired by a qualied technician using
the proper equipment and quality replacement parts.
Poorly performed collision repairs diminish your vehicle’s
resale value, and safety performance can be
compromised in subsequent collisions.
Collision Parts
Genuine GM Collision parts are new parts made with the
same materials and construction methods as the parts
with which your vehicle was originally built. Genuine GM
Collision parts are your best choice to ensure that your
vehicle’s designed appearance, durability, and safety are
preserved. The use of Genuine GM parts can help
maintain your GM New Vehicle Warranty.
Recycled original equipment parts may also be used for
repair. These parts are typically removed from vehicles
that were total losses in prior crashes. In most cases,
the parts being recycled are from undamaged sections
of the vehicle. A recycled original equipment GM part,
may be an acceptable choice to maintain your vehicle’s
originally designed appearance and safety performance,
however, the history of these parts is not known.
Such parts are not covered by your GM New Vehicle
Limited Warranty, and any related failures are not
covered by that warranty.
7-12