1999 GMC YUKON maintenance

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The 1999 GMC Yukon Denali Owner's Manual
1-1 Seats and Restraint SystemsThis section tells you how to use your seats and safety belts properly. It also explains the air bag system.
2-1 Features and ControlsThis section explains how to start and operate your vehicle.
3-1 Comfort Controls and Audio SystemsThis section tells you how to adjust the ventilation and comfort controls and how to operate your audio system.
4-1 Your Driving and the RoadHere you'll find helpful information and tips about the road and how to drive under different conditions.
5-1 Problems on the RoadThis section tells you what to do if you have a problem while driving, such as a flat tire or overheated engine, etc.
6-1 Service and Appearance CareHere the manual tells you how to keep your vehicle running properly and looking good.
7-1 Maintenance ScheduleThis section tells you when to perform vehicle maintenance and what fluids and lubricants to use.
8-1 Customer Assistance InformationThis section tells you how to contact GMC for assistance and how to get service and owner publications.
It also gives you information on ªReporting Safety Defectsº on page 8-10.
9-1 IndexHere's an alphabetical listing of almost every subject in this manual. You can use it to quickly find
something you want to read.

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NOTICE:
If you damage the covering for the driver's or the
right front passenger's air bag, the bag may not
work properly. You may have to replace the air
bag module in the steering wheel or both the air
bag module and the instrument panel for the
right front passenger's air bag. Do not open or
break the air bag coverings.
If your vehicle ever gets into a lot of water -- such as
water up to the carpeting or higher
-- or if water enters
your vehicle and soaks the carpet, the air bag controller
can be soaked and ruined. If this ever happens, and then
you start your vehicle, the damage could make the air bags
inflate, even if there's no crash. You would have to replace
the air bags as well as the sensors and related parts. If your
vehicle is ever in a flood, or if it's exposed to water that
soaks the carpet, you can avoid needless repair costs by
turning off the vehicle immediately and disconnecting the
battery cables. Don't let anyone start the vehicle under any
circumstances. See your dealer for service.
Servicing Your Air Bag-Equipped Vehicle
Air bags affect how your vehicle should be serviced.
There are parts of the air bag system in several places
around your vehicle. You don't want the system to
inflate while someone is working on your vehicle. Your
dealer and the GM Service Manual have information
about servicing your vehicle and the air bag system. To
purchase a service manual, see ªService and Owner
Publicationsº in the Index.
CAUTION:
For up to 10 minutes after the ignition key is
turned off and the battery is disconnected, an air
bag can still inflate during improper service. You
can be injured if you are close to an air bag when
it inflates. Avoid yellow connectors. They are
probably part of the air bag system. Be sure to
follow proper service procedures, and make sure
the person performing work for you is qualified
to do so.
The air bag system does not need regular maintenance.

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Safety Belt Extender
If the vehicle's safety belt will fasten around you, you
should use it.
But if a safety belt isn't long enough to fasten, your
dealer will order you an extender. It's free. When you go
in to order it, take the heaviest coat you will wear, so the
extender will be long enough for you. The extender will
be just for you, and just for the seat in your vehicle that
you choose. Don't let someone else use it, and use it
only for the seat it is made to fit. To wear it, just attach it
to the regular safety belt.
Checking Your Restraint Systems
Now and then, make sure the safety belt reminder light
and all your belts, buckles, latch plates, retractors and
anchorages are working properly. Look for any other
loose or damaged safety belt system parts. If you see
anything that might keep a safety belt system from
doing its job, have it repaired.
Torn or frayed safety belts may not protect you in a
crash. They can rip apart under impact forces. If a belt is
torn or frayed, get a new one right away.
Also look for any opened or broken air bag covers, and
have them repaired or replaced. (The air bag system
does not need regular maintenance.)
Replacing Restraint System Parts
After a Crash
If you've had a crash, do you need new belts?
After a very minor collision, nothing may be necessary.
But if the belts were stretched, as they would be if worn
during a more severe crash, then you need new belts.
If belts are cut or damaged, replace them. Collision
damage also may mean you will need to have safety belt
or seat parts repaired or replaced. New parts and repairs
may be necessary even if the belt wasn't being used at
the time of the collision.
If an air bag inflates, you'll need to replace air bag
system parts. See the part on the air bag system earlier in
this section.

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NOTICE:
If you keep driving your vehicle with this light
on, after a while, your emission controls may not
work as well, your fuel economy may not be as
good and your engine may not run as smoothly.
This could lead to costly repairs that may not be
covered by your warranty.
NOTICE:
Modifications made to the engine, transmission,
exhaust or fuel system of your vehicle or the
replacement of the original tires with other than
those of the same Tire Performance Criteria
(TPC) can affect your vehicle's emission controls
and may cause the SERVICE ENGINE SOON
light to come on. Modifications to these systems
could lead to costly repairs not covered by your
warranty. This may also result in a failure to pass
a required Emission Inspection/Maintenance test.
This light should come on, as a check to show you it is
working, when the ignition is on and the engine is not
running. If the light doesn't come on, have it repaired.
This light will also come on during a malfunction in one
of two ways:

Light Flashing
-- A misfire condition has been
detected. A misfire increases vehicle emissions and
may damage the emission control system on your
vehicle. Dealer or qualified service center diagnosis
and service may be required.

Light On Steady
-- An emission control system
malfunction has been detected on your vehicle.
Dealer or qualified service center diagnosis and
service may be required.
If the Light Is Flashing
The following may prevent more serious damage to
your vehicle:

Reducing vehicle speed.

Avoiding hard accelerations.

Avoiding steep uphill grades.

If you are towing a trailer, reduce the amount of
cargo being hauled as soon as it is possible.

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4-15 Before You Go Off-Roading
There are some things to do before you go out. For
example, be sure to have all necessary maintenance and
service work done. Check to make sure all underbody
shields (if so equipped) are properly attached. Be sure
you read all the information about your
four
-wheel-drive vehicle in this manual. Is there enough
fuel? Is the spare tire fully inflated? Are the fluid levels
up where they should be? What are the local laws that
apply to off
-roading where you'll be driving? If you
don't know, you should check with law enforcement
people in the area. Will you be on someone's private
land? If so, be sure to get the necessary permission.
Loading Your Vehicle for Off-Road Driving
There are some important things to remember about
how to load your vehicle.

The heaviest things should be on the load floor and
forward of your rear axle. Put heavier items as far
forward as you can.

Be sure the load is secured properly, so driving on
the off
-road terrain doesn't toss things around.
CAUTION:

Cargo on the load floor piled higher than
the seatbacks can be thrown forward
during a sudden stop. You or your
passengers could be injured. Keep cargo
below the top of the seatbacks.

Unsecured cargo on the load floor can be
tossed about when driving over rough
terrain. You or your passengers can be
struck by flying objects. Secure the
cargo properly.

Heavy loads on the roof raise the vehicle's
center of gravity, making it more likely to
roll over. You can be seriously or fatally
injured if the vehicle rolls over. Put heavy
loads inside the cargo area, not on the roof.
Keep cargo in the cargo area as far forward
and low as possible.
You'll find other important information in this manual.
See ªVehicle Loading,º ªLuggage Carrierº and ªTiresº
in the Index.

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CAUTION:
Driving through rushing water can be dangerous.
Deep water can sweep your vehicle downstream
and you and your passengers could drown. If it's
only shallow water, it can still wash away the
ground from under your tires, and you could lose
traction and roll the vehicle over. Don't drive
through rushing water.
See ªDriving Through Waterº in the Index for more
information on driving through water.
After Off-Road Driving
Remove any brush or debris that has collected on the
underbody, chassis or under the hood. These
accumulations can be a fire hazard.
After operation in mud or sand, have the brake linings
cleaned and checked. These substances can cause
glazing and uneven braking. Check the body structure,
steering, suspension, wheels, tires and exhaust system
for damage. Also, check the fuel lines and cooling
system for any leakage.
Your vehicle will require more frequent service due to
off
-road use. Refer to the Maintenance Schedule for
additional information.

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4-53 When You Are Ready to Leave After
Parking on a Hill
1. Apply your regular brakes and hold the pedal down
while you:

Start your engine;

Shift into a gear; and

Release the parking brake.
2. Let up on the brake pedal.
3. Drive slowly until the trailer is clear of the chocks.
4. Stop and have someone pick up and store the chocks.
Maintenance When Trailer Towing
Your vehicle will need service more often when you're
pulling a trailer. See the Maintenance Schedule for more
on this. Things that are especially important in trailer
operation are automatic transmission fluid (don't
overfill), engine oil, axle lubricant, belt, cooling system
and brake adjustment. Each of these is covered in this
manual, and the Index will help you find them quickly.
If you're trailering, it's a good idea to review these
sections before you start your trip.
Check periodically to see that all hitch nuts and bolts
are tight.
Trailer Wiring Harness
Light-Duty Wiring Harness

6-
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Section 6 Service and Appearance Care
Here you will find information about the care of your vehicle. This section begins with service and fuel information,
and then it shows how to check important fluid and lubricant levels. There is also technical information about your
vehicle, and a part devoted to its appearance care.
6
-2 Service
6
-3 Fuel
6
-5 Fuels in Foreign Countries
6
-5 Filling Your Tank
6
-8 Filling a Portable Fuel Container
6
-8 Checking Things Under the Hood
6
-11 Engine Oil
6
-15 Engine Air Cleaner/Filter
6
-17 Automatic Transmission Fluid
6
-20 Rear Axle
6
-21 Four-Wheel Drive
6
-22 Radiator Pressure Cap
6
-23 Thermostat
6
-23 Engine Coolant
6
-27 Power Steering Fluid
6
-28 Windshield Washer Fluid6
-29 Brakes
6
-33 Battery
6
-34 Bulb Replacement
6
-38 Windshield Wiper Blade Replacement
6
-39 Tires
6
-47 Appearance Care
6
-47 Cleaning the Inside of Your Vehicle
6
-50 Care of the Safety Belts
6
-51 Cleaning the Outside of Your Vehicle
6
-54 GM Vehicle Care/Appearance Materials
6
-55 Vehicle Identification Number (VIN)
6
-56 Electrical System
6
-61 Replacement Bulbs
6
-63 Capacities and Specifications
6
-64 Air Conditioning Refrigerants
6
-65 Normal Maintenance Replacement Parts