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2-27
AUTOMATIC OVERDRIVE (): This position is for
normal driving. If you need more power for passing,
and you're:
Going less than about 35 mph (56 km/h), push your
accelerator pedal about halfway down.
Going about 35 mph (56 km/h) or more, push the
accelerator all the way down.
You'll shift down to the next gear and have
more power.
AUTOMATIC OVERDRIVE () can be used when
towing a trailer, carrying a heavy load, driving on steep
hills or for off
-road driving. You may want to shift the
transmission to THIRD (3) or, if necessary, a lower gear
selection if the transmission shifts too often.
THIRD (3): This position is also used for normal
driving, however, it offers more power and lower fuel
economy than AUTOMATIC OVERDRIVE ().
SECOND (2): This position gives you more power but
lower fuel economy. You can use SECOND (2) on hills.
It can help control your speed as you go down steep
mountain roads, but then you would also want to use
your brakes off and on.If you manually select SECOND (2), the transmission will
drive in second gear. You may use this feature for reducing
torque to the rear wheels when you are trying to start your
vehicle from a stop on slippery road surfaces.
FIRST (1): This position gives you even more power
(but lower fuel economy) than SECOND (2). You can
use it on very steep hills, or in deep snow or mud. If the
selector lever is put in FIRST (1) while the vehicle is
moving forward, the transmission won't shift into first
gear until the vehicle is going slowly enough.NOTICE:
If your rear wheels can't rotate, don't try to
drive. This might happen if you were stuck in
very deep sand or mud or were up against a solid
object. You could damage your transmission.
Also, if you stop when going uphill, don't hold
your vehicle there with only the accelerator
pedal. This could overheat and damage the
transmission. Use your brakes or shift into
PARK (P) to hold your vehicle in position on
a hill.
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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
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5-4
1. Check the other vehicle. It must have a 12-volt
battery with a negative ground system.
NOTICE:
If the other system isn't a 12-volt system with a
negative ground, both vehicles can be damaged.
2. Get the vehicles close enough so the jumper cables
can reach, but be sure the vehicles aren't touching
each other. If they are, it could cause a ground
connection you don't want. You wouldn't 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 firmly on both vehicles involved in
the jump start procedure. Put an automatic
transmission in PARK (P) or a manual transmission
in NEUTRAL (N) before setting the parking brake.
Be sure the transfer case is not in NEUTRAL (N).3. Turn off the ignition on both vehicles. Unplug
unnecessary accessories plugged into the cigarette
lighter or accessory power outlets. Turn off all lamps
that aren't needed as well as radios. This will avoid
sparks and help save both batteries. And it could
save your radio!
NOTICE:
If you leave your radio on, it could be badly
damaged. The repairs wouldn't be covered by
your warranty.
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8-12
CURRENT PUBLICATIONS FOR 1999 GMC
SERVICE MANUALS
Service Manuals have the diagnosis and repair information
on engines, transmission, axle, suspension, brakes,
electrical, steering, body, etc.
RETAIL SELL PRICE: $90.00
TRANSMISSION, TRANSAXLE, TRANSFER CASE
UNIT REPAIR MANUAL
This manual provides information on unit repair service
procedures, adjustments and specifications for the
1999 GM transmissions, transaxles and transfer cases.
RETAIL SELL PRICE: $50.00
SERVICE BULLETINS
Service Bulletins give technical service information needed
to knowledgeably service General Motors cars and trucks.
Each bulletin contains instructions to assist in the
diagnosis and service of your vehicle.OWNER'S INFORMATION
Owner publications are written directly for Owners and
intended to provide basic operational information about the
vehicle. The owner's manual will include the Maintenance
Schedule for all models.
In-Portfolio: Includes a Portfolio, Owner's Manual and
Warranty Booklet.
RETAIL SELL PRICE: $15.00
Without Portfolio: Owner's Manual only.
RETAIL SELL PRICE: $10.00
CURRENT & PAST MODEL ORDER FORMS
Service Publications are available for current and past
model GM vehicles. To request an order form, please
specify year and model name of the vehicle.
PLEASE COMPLETE THE ORDER FORM SHOWN ON
THE FOLLOWING PAGE AND MAIL TO:
Helm, Incorporated P.O. Box 07130 Detroit, MI 48207OR ORDER TOLL FREE: 1-800-551-4123
Monday-Friday 8:00 AM ± 6:00 PM Eastern Time
For Credit Card Orders Only (VISA±MasterCard±Discover)
1999 GMC SERVICE PUBLICATIONS ORDERING INFORMATION
The following publications covering the operation and servicing of your vehicle can be purchased by filling out
the Service Publication Order Form in this book and mailing it in with your check, money order,
or credit card information to Helm, Incorporated (address below.)
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8-13
PUBLICATION FORM
NUMBEROrders will be mailed within 10 days of receipt. Please allow adequate time for postal
service. If further information is needed, write to the address shown below or call
1-800-551-4123. Material cannot be returned for credit without packing slip with return
information within 30 days of delivery. On returns, a re-stocking fee may be applied
against the original order. ORDER TOLL FREE
(NOTE: For Credit Card Holders Only)1-800-551-4123(Monday-Friday 8:00 AM ± 6:00 PM EST)
FAX Orders Only 1-313-865-5927
Service Manual
NOTE: Dealers and Companies please provide dealer or company name, and also the
name of the person to whose attention the shipment should be sent.
Mail completed order form to:
HELM, INCORPORATED P.O. Box 07130 Detroit, MI 48207
For purchases outside U.S.A. please write to the above address for quotation.
1999$90.00
1999
$50.00
1999
$15.00
1999
$10.00
TOTAL MATERIAL
Michigan Purchasers
U.S. Order Processing$5.00
Canadian Postage
GRAND TOTAL
add 6% sales tax
(See Note Below)
GM-GMC-ORD99 *(Prices are subject to change without notice and without incurring
obligation. Allow ample time for delivery.)Note to Canadian Customers: All listed prices are quoted in U.S. funds. Canadian residents
are to make checks payable in U.S. funds. To cover Canadian postage, add $11.50 plus the
U.S. order processing.
(CUSTOMER'S NAME) (ATTENTION)
(STREET ADDRESSÐNO P.O. BOX NUMBERS)
(CITY) (ZIP CODE)
DAYTIME TELEPHONE NO.(STATE)
AREA CODE
( )P
Check or Money
Order payable to
Helm, Inc. (USA funds
only Ð
do not send cash.)
VISA
Discover
Account
Number:
Expiration
Date mo/yr:
CUSTOMER SIGNATURE
S
ITEM DESCRIPTIONNAME YEAR VEHICLE MODEL
QTY.PRICE
EACH*TOTAL
PRICE1
9
9
9
G
M
H
I
P
T
OA
Y
M
E
N
T
Owner's Manual Without Portfolio Owner's Manual In Portfolio Car & Light Truck
Transmission Unit Repair
MasterCard
Check here if your billing address
is different from your shipping
address shown.
PUBLICATION FORM
NUMBER
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9-4
Electronic Compass 2-51 . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Engine 6-10 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Air Cleaner/Filter 6-15, 6-64 . . . . . . . . . . . . . . . . . . . . . . . .
Coolant 6-23, 7-41 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Coolant Heater 2-24 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Coolant Level Check 7-35 . . . . . . . . . . . . . . . . . . . . . . . . . .
Coolant Temperature Gage 2-76 . . . . . . . . . . . . . . . . . . . . .
Cooling System 6-64 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Exhaust 2-36, 4-41 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Identification 6-55 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Oil Level Check 7-35 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Overheating 5-9 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Running While Parked 2-37 . . . . . . . . . . . . . . . . . . . . . . . . .
Specifications 6-63 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Starting Your 2-22 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Engine Oil 6-11, 6-65, 7-41 . . . . . . . . . . . . . . . . . . . . . . . . . .
Adding 6-11 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Additives 6-13 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Checking 6-11 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Pressure Gage 2-79 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Used 6-14 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
When to Change 6-14 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Equipment, Adding to the Outside of Your Vehicle 6-3 . . . . . .
Ethanol 6-4 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Exhaust, Engine 2-36, 4-41 . . . . . . . . . . . . . . . . . . . . . . . . . . .
Exit Lighting and Delayed Illumination 2-49 . . . . . . . . . . . . .
Exterior Lamps 2-46 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Fabric Cleaning 6-47 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Feature Customization 2-16 . . . . . . . . . . . . . . . . . . . . . . . . . . .
Driver's Door Alarm Delay 2-19 . . . . . . . . . . . . . . . . . . . . .
Keyless Entry Verification 2-17 . . . . . . . . . . . . . . . . . . . . . .
Leaving Programming Mode 2-19 . . . . . . . . . . . . . . . . . . . .
Lockout Prevention 2-17 . . . . . . . . . . . . . . . . . . . . . . . . . . . Theft
-Deterrent Arming Method 2-18 . . . . . . . . . . . . . . . . .
Theft-Deterrent Arming Verification 2-19 . . . . . . . . . . . . . .
Filling a Portable Fuel Container 6-8 . . . . . . . . . . . . . . . . . . . .
Filling Your Tank 6-5 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Filter, Air Cleaner 6-15, 6-64 . . . . . . . . . . . . . . . . . . . . . . . . .
Filter, Engine Oil 6-14, 6-64 . . . . . . . . . . . . . . . . . . . . . . . . . .
Finish Care 6-51 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Finish Damage 6-53 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
First Gear, Automatic Transmission 2-27 . . . . . . . . . . . . . . . .
Flashers, Hazard Warning 5-2 . . . . . . . . . . . . . . . . . . . . . . . . .
Flat Tire, Changing 5-19 . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Fluid Capacities 6-63 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Fluid Leak Check 6-33 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Fluids and Lubricants 7-41 . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Fog Lamps 2-48, 6-36, 6-61 . . . . . . . . . . . . . . . . . . . . . . . . . .
Folding the Rear Seat 1-6 . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Foreign Countries, Fuel 6-5 . . . . . . . . . . . . . . . . . . . . . . . . . . .
Four-Wheel Drive 2-28, 6-21 . . . . . . . . . . . . . . . . . . . . . . . . .
French Language Manual ii. . . . . . . . . . . . . . . . . . . . . . . . . . .
Front Axle 6
-22, 7-42 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Front Axle Locking Feature 2-28 . . . . . . . . . . . . . . . . . . . . . . .
Front Park/Turn Signal Bulb Replacement 6-36, 6-61 . . . . . .
Front Sidemarker Lamp Bulb Replacement 6-36, 6-61 . . . . . .
Front Towing 5-8 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Fuel 6-3 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Canada 6-3 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Filling a Portable Container 6-8 . . . . . . . . . . . . . . . . . . . . . .
Filling Your Tank 6-5 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Gage 2-82 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
In Foreign Countries 6-5 . . . . . . . . . . . . . . . . . . . . . . . . . . .
System Capacity 6-64 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Fuses and Circuit Breakers 6-57 . . . . . . . . . . . . . . . . . . . . . . .
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9-9
Driver Position 1-14 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Extender 1-57 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
How to Wear Properly 1-14 . . . . . . . . . . . . . . . . . . . . . . . . .
Incorrect Usage 1-17, 1-55, 1-56 . . . . . . . . . . . . . . . . . . . .
Lap Belt 1-37 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Lap-Shoulder 1-14, 1-31 . . . . . . . . . . . . . . . . . . . . . . . . . . .
Larger Children 1-54 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Passenger Position 1-23 . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Questions and Answers 1-13 . . . . . . . . . . . . . . . . . . . . . . . .
Rear Comfort Guides 1-34 . . . . . . . . . . . . . . . . . . . . . . . . . .
Rear Seat Outside Passenger Positions 1-30 . . . . . . . . . . . .
Rear Seat Passengers 1-30 . . . . . . . . . . . . . . . . . . . . . . . . . .
Reminder Light 1-10, 2-72 . . . . . . . . . . . . . . . . . . . . . . . . .
Replacing After a Crash 1-57 . . . . . . . . . . . . . . . . . . . . . . . .
Right Front Passenger Position 1-23 . . . . . . . . . . . . . . . . . .
Shoulder Belt Height Adjuster 1-16, 1-32 . . . . . . . . . . . . . .
Smaller Children and Babies 1-38 . . . . . . . . . . . . . . . . . . . .
Use During Pregnancy 1-22 . . . . . . . . . . . . . . . . . . . . . . . . .
Why They Work 1-10 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Safety Chains 4-48 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Safety Defects, Reporting 8-10 . . . . . . . . . . . . . . . . . . . . . . . .
Safety Warnings and Symbols iii. . . . . . . . . . . . . . . . . . . . . . .
Scheduled Maintenance Services 7
-4 . . . . . . . . . . . . . . . . . . . .
Seatback, Reclining Front 1-4 . . . . . . . . . . . . . . . . . . . . . . . . . Seats
Folding the Rear 1
-6 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Heated Front 1-3 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Heated Rear 1-8 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Lumbar Adjustment 1-3 . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Power 1-2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Rear 1-6 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Restraint Systems 1-1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Seat Controls 1-2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Securing a Child Restraint 1-48, 1-50, 1-52 . . . . . . . . . . . .
Second Gear, Automatic Transmission 2-27 . . . . . . . . . . . . . .
Security Light 2-80 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Security Shade 2-58 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Service 6-2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Bulletins, Ordering 8-12, 8-13 . . . . . . . . . . . . . . . . . . . . . . .
Engine Soon Light 2-76 . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Manuals, Ordering 8-12, 8-13 . . . . . . . . . . . . . . . . . . . . . . .
Parts Identification Label 6-55 . . . . . . . . . . . . . . . . . . . . . . .
Publications, Ordering 8-12, 8-13 . . . . . . . . . . . . . . . . . . . .
Work, Doing Your Own 6-2 . . . . . . . . . . . . . . . . . . . . . . . . .
Service and Appearance Care 6-1 . . . . . . . . . . . . . . . . . . . . . .
Service and Owner Publications 8-12, 8-13 . . . . . . . . . . . . . .
Service Four-Wheel Drive Warning Light 2-80 . . . . . . . . . . . .
Service Publications 8-12, 8-13 . . . . . . . . . . . . . . . . . . . . . . . .