fuel GMC SUBURBAN 1999 Owner's Manual

Table of Contents (cont'd)
Maintenance Schedule
Service and Appearance Care
Section
Section
Scheduled Maintenance
Periodic Maintenance Inspections
Recommended Fluids and Lubricants
Maintenance Records
Fuel
Checking Fluids and Lubricants
GM Oil Life System™
Passenger Compartment Air Filter (If Equipped)
Bulb Replacement
Windshield Wiper Blade Replacement
Tires and Wheels
Appearance Care
Electrical System/Fuses and Circuit Breakers
Capacities and Specifications
Normal Maintenance Replacement Parts

ix
For example,
these symbols
are used on an
original battery:
CAUTION
POSSIBLE
INJURY
PROTECT
EYES BY
SHIELDING
CAUSTIC
BATTERY
ACID COULD
CAUSE
BURNS
AVOID
SPARKS OR
FLAMES
SPARK OR
FLAME
COULD
EXPLODE
BATTERY
These symbols
are important
for you and
your passengers
whenever your
vehicle is
driven:
DOOR LOCK
UNLOCK
FASTEN
SEAT
BELTS
POWER
WINDOW
AIR BAG
These symbols
have to do with
your lamps:
MASTER
LIGHTING
SWITCH
TURN
SIGNALS
PARKING
LAMPS
HAZARD
WARNING
FLASHER
DAYTIME
RUNNING
LAMPS
FOG LAMPS
These symbols
are on some of
your controls:
WINDSHIELD
WIPER
WINDSHIELD
WASHER
WINDSHIELD
DEFROSTER
REAR
WINDOW
DEFOGGER
VENTILATING
FAN
These symbols
are used on
warning and
indicator lights:
ENGINE
COOLANT
TEMP
BATTERY
CHARGING
SYSTEM
BRAKE
COOLANT
ENGINE OIL
PRESSURE
ANTI-LOCK
BRAKES
Here are some
other symbols
you may see:
FUSE
LIGHTER
HORN
SPEAKER
FUEL
Vehicle Symbols
These are some of the symbols you may find on your vehicle.

Service Station Guide
Oil Viscosity
Engine Oil
See Section 6
Engine Oil Dipstick
See Section 6Fuel
Use unleaded gas only,
87 Octane or higher.
See Section 6
Cooling System
See Section 5
Hood Release
See Section 6
Windshield Washer
Fluid
See Section 6
Spare Tire Pressure
See Section 5
Battery
See Section 6
Tire Pressure
See Section 6
For
a More
Detailed Look at
What's Under the Hood
See Section 6

2-13 Testing the Alarm
The alarm can be tested by following these steps:
1. From inside the vehicle, lower the driver's window
and open the driver's door.
2. Activate the system by locking the doors with the
power door lock switch while the door is open, or
with the remote keyless entry transmitter.
3. Get out of the vehicle, close the door and wait for the
SECURITY message to go out.
4. Then reach in through the window, unlock the door
with the manual door lock and open the door. This
should set off the alarm.
If the alarm does not sound when it should but the
vehicle's headlamps flash, check to see if the horn
works. The horn fuse may be blown. To replace the fuse,
see ªFuses and Circuit Breakersº in the Index.
If the alarm does not sound or the vehicle's headlamps
do not flash, the vehicle should be serviced by an
authorized service center.
Passlock

Your vehicle is equipped with the Passlock
theft
-deterrent system.
Passlock is a passive theft
-deterrent system. Passlock
enables fuel if the ignition lock cylinder is turned with a
valid key. If a correct key is not used or the ignition lock
cylinder is tampered with, fuel is disabled.
If the engine stalls and the SECURITY message flashes,
wait until the light stops flashing before trying to restart
the engine. Remember to release the key from START
as soon as the engine starts.
If the engine is running and the SECURITY message
comes on, you will be able to restart the engine if you
turn the engine off. However, your Passlock system is
not working properly and must be serviced by your
dealer. Your vehicle is not protected by Passlock at this
time. You may also want to check the fuse (see ªFuses
and Circuit Breakersº in the Index). See your dealer
for service.
In an emergency, call the GM Roadside Assistance
Center. See ªRoadside Assistanceº in the Index.

2-17
NOTICE:
Your engine is designed to work with the
electronics in your vehicle. If you add electrical
parts or accessories, you could change the way
the engine operates. Before adding electrical
equipment, check with your dealer. If you don't,
your engine might not perform properly.
If you ever have to have your vehicle towed,
see the part of this manual that tells how to do
it without damaging your vehicle. See ªTowing
Your Vehicleº in the Index.
Engine Coolant Heater (If Equipped)
In very cold weather,
0
F (
-18
C) or colder,
the engine coolant heater
can help. You'll get easier
starting and better fuel
economy during engine
warm
-up. Usually, the
coolant heater should be
plugged in a minimum of
four hours prior to starting
your vehicle.
To Use the Engine Coolant Heater
1. Turn off the engine.
2. Open the hood and unwrap the electrical cord.
The cord is located on the driver's side of the engine
compartment, near the power steering fluid reservoir.
3. Plug it into a normal, grounded 110
-volt AC outlet.

2-21
THIRD (3): This position is also used for normal
driving, however it offers more power and lower fuel
economy than DRIVE (D).
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) in a light duty
automatic transmission, the transmission will drive in
second gear. You may use this feature for reducing the
speed of 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.
On cold days, approximately 32
F (0
C) or colder,
your transmission is designed to shift differently until
the engine reaches normal operating temperature.
This is intended to improve heater performance.

2-23 Automatic Transfer Case (If Equipped)
The transfer case switches
are located to the left of the
instrument panel cluster.
Use these switches to shift into and out of
four
-wheel drive.
You can choose among four driving settings:
2HI: This setting is used for driving in most street and
highway situations. Your front axle is not engaged in
two
-wheel drive. This setting also provides the best
fuel economy.

2-24
AUTO 4WD: This setting is ideal for use when road
conditions are variable. When driving your vehicle in
AUTO 4WD, the front axle is engaged, but the vehicle's
power is sent only to the rear wheels. When the vehicle
senses a loss of traction, the system will automatically
engage four
-wheel drive. Driving in this mode results in
slightly lower fuel economy than 2HI.
4HI: Use 4HI when you need extra traction, such as
on snowy or icy roads or in most off
-road situations.
This setting also engages your front axle to help drive
your vehicle. This is the best setting to use when
plowing snow.
4LO: This setting also engages your front axle and
delivers extra torque. You may never need 4LO. It sends
maximum power to all four wheels. You might choose
4LO if you are driving off
-road in deep sand, deep mud,
deep snow and climbing or descending steep hills.
CAUTION:
Shifting the transfer case to NEUTRAL can
cause your vehicle to roll even if the transmission
is in PARK (P). You or someone else could be
seriously injured. Be sure to set the parking
brake before placing the transfer case in
NEUTRAL. See ªParking Brakeº in the Index.
NEUTRAL: Shift the vehicle's transfer case to NEUTRAL
only when towing your vehicle. See ªRecreational Vehicle
Towingº or ªTowing Your Vehicleº in the Index for
more information.
Indicator lights in the switches show which setting you are
in. The indicator lights will come on briefly when you turn
on the ignition and one will stay on. If the lights do not
come on, you should take your vehicle to your dealer for
service. An indicator light will flash while shifting the
transfer case. It will remain illuminated when the shift is
complete. If for some reason the transfer case cannot make
a requested shift, it will return to the last chosen setting.

2-68
Instrument Panel Cluster
United States Heavy Duty Transmission version shown.
Canada and Light Duty Transmission clusters are similar.
Your instrument cluster is designed to let you know at a glance how your vehicle is running. You'll know how fast you're
going, about how much fuel you have and many other things you'll need to know to drive safely and economically.

2-77
The TRACTION OFF light may come on for the
following reasons:

If you turn the system off by pressing the TAS on/off
button located to the left of the steering wheel, the
light will come on and stay on. To turn the system
back on, press the button again; the light should
go off.

If you move the shift lever to FIRST (1), the light
will come on and stay on to indicate that the Traction
Assist System is off. This is normal operation. To
turn the system back on, move the shift lever back to
a position other than FIRST (1); the light should go
off. See ªTraction Assist Systemº in the Index.

The light will come on and stay on if the TAS
automatic engagement feature has been turned off.
To turn the system on, press the TAS off/on button;
the light should go off. To turn the automatic
engagement feature back on, see ªTraction Assist
Systemº in the Index.

If the Traction Assist System is affected by an
engine
-related problem, the system will turn off and
the light will come on. Have your vehicle serviced.
Malfunction Indicator Lamp
(Service Engine Soon Light in the United
States or Check Engine Light in Canada)
United States Canada
Your vehicle is equipped with a computer which
monitors operation of the fuel, ignition and emission
control systems.
This system is called OBD II (On
-Board
Diagnostics
-Second Generation) and is intended to assure
that emissions are at acceptable levels for the life of the
vehicle, helping to produce a cleaner environment. The
SERVICE ENGINE SOON or CHECK ENGINE light
comes on to indicate that there is a problem and service is
required. Malfunctions often will be indicated by the
system before any problem is apparent. This may prevent
more serious damage to your vehicle. This system is also
designed to assist your service technician in correctly
diagnosing any malfunction.