2003 CHEVROLET SUBURBAN overheating

Ashtrays and Cigarette Lighter
The front ashtray is located near the center of the
instrument panel or on the front console, if equipped.
Pull on the ashtray door to open it.
Notice:Don't put papers or other ¯ammable
items into your ashtrays. Hot cigarettes or other
smoking materials could ignite them, causing
a damaging ®re.
To remove the front ashtray pull the ashtray up.
To use the cigarette lighter, push it in all the way, and
let go. When it's ready, it will pop back out by itself.
Notice:Holding a cigarette lighter in while it
is heating will not allow the lighter to back away
from the heating element when it is hot. Damage
from overheating may occur to the lighter or heating
element, or a fuse could be blown. Do not hold a
cigarette lighter in while it is heating.
Climate Controls
Climate Control System
Fan Knob
The fan knob on the left side of the control panel
adjusts the fan speed. To increase air¯ow, turn the knob
clockwise. To decrease air¯ow, turn it counterclockwise.
To turn the fan off, turn the knob to the off position.
9(Off):If the fan is off, outside air will still enter the
vehicle, and will be directed based on the position of
the mode knob. The temperature can also be adjusted
using the temperature knob.
3-20

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
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
Traction Assist System (TAS) on page 4-10.
·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
Traction Assist
System (TAS) on page 4-10.
·If the Traction Assist System is affected by an
anti-lock brake system, TAS or engine-related
problem, the system will turn off and the light will
come on. Have your vehicle serviced.
·If the vehicle is driven over an extremely rough road,
the system will turn off and the light will come on. The
light will go off a few seconds after the rough road
conditions go away or when the vehicle comes to a
complete stop. This is normal operation.
Engine Coolant Temperature Gage
This gage shows the engine coolant temperature.
It also provides an indicator of how hard your vehicle is
working. During a majority of the operation, the gage
will read 210ÉF (100ÉC) or less. If you are pulling a load
or going up hills, it is normal for the temperature to
¯uctuate and approach the 250ÉF (122ÉC) mark. If the
gage reaches the 260ÉF (125ÉC) mark, it indicates
that the cooling system is working beyond its capacity.
See
Engine Overheating on page 5-33. United States
Canada
3-45

REDUCED ENGINE POWER
This message is displayed when the cooling system
temperature gets too hot and the engine further enters
the engine coolant protection mode.
See
Engine Overheating on page 5-33for further
information.
REPLACE LIFTGATE FUSE
This message will be displayed if the liftgate lock
malfunctions and/or the liftgate fuse blows. For more
information on fuses, see
Fuses and Circuit Breakers on
page 5-109.
If the message returns after replacing the fuse, see you
dealer for service.
KEYFOB X BATTERY LOW
If a remote keyless entry transmitter battery is low, this
message will appear on the DIC. The battery needs
to be replaced in the transmitter. Press the select button
to acknowledge the message and clear it from the
DIC display.
SERVICE AIRBAG
If there is a problem with the air bag system, this
message will be displayed on the DIC. Have a quali®ed
technician inspect the system for problems. Press
the select button to acknowledge this message and clear
it from the DIC display.
SERVICE BRAKE SYSTEM
If there is a problem with the brake system, this
message will be displayed on the DIC. If this message
appears, stop as soon as possible and turn off the
vehicle. Restart the vehicle and check for the message
on the DIC display. If the message is still displayed,
or appears again when you begin driving, the brake
system needs service. Press the select button to
acknowledge the message.
SERVICE 4 WHEEL STEER
If a problem occurs with the 4 wheel steer system, this
message will appear on the DIC. If the message
appears, stop as soon as possible, and turn off the
vehicle. Restart the vehicle and check for the message
on the DIC display. If the message is still displayed,
or appears again when you begin driving, the four wheel
steer system needs service. Press the select button
to acknowledge the message.
3-68

STABILITY SYS ACTIVE
You may see the STABILITY SYS ACTIVE message on
the DIC. It means that an advanced computer-controlled
system has come on to help your vehicle continue to go
in the direction in which you're steering.
Stabilitrak
žactivates when the computer senses that
your vehicle is just starting to spin, as it might if you hit a
patch of ice or other slippery spot on the road. When the
system activates, you may hear a noise or feel a vibration
in the brake pedal. This is normal. When the STABILITY
SYS ACTIVE message is on, you should continue to
steer in the direction you want to go. The system is
designed to help you in bad weather or other difficult
driving situations by making the most of whatever road
conditions will permit.
STABILITY SYS DISABLED
The STABILITY SYS DISABLED message will turn on
when you press the Stabilitrakžbutton, or when the
stability control has been automatically disabled. To limit
wheel spin and realize the full bene®ts of the stability
enhancement system, you should normally leave
Stabilitrak
žon. However, you should turn Stabilitrakžoff
if your vehicle gets stuck in sand, mud, ice or snow and
you want to ªrockº your vehicle to attempt to free it, or if
you are driving in extreme off-road conditions and require
more wheel spin. See
If You Are Stuck: In Sand, Mud, Ice
or Snow on page 4-56. To turn the Stabilitrakžsystem
back on press the Stabilitrakžbutton again. There arefour conditions that can cause this message to appear.
One condition is overheating, which could occur if
Stabilitrak
žactivates continuously for an extended period
of time. The message will also be displayed if the brake
system warning light is on. See
Brake System Warning
Light on page 3-42. The message could be displayed if
the stability system takes longer than usual to complete
its diagnostic checks due to driving conditions. Also, if an
engine or vehicle related problem has been detected, and
the vehicle needs service, the message will appear.
The message will turn off as soon as the conditions that
caused the message to be displayed are no longer
present.
STABILITY SYS READY
Text under development.
TIGHTEN FUEL CAP
If the vehicle's fuel cap is not tightened properly this
message may appear along with the check engine light
on the instrument panel. Reinstall the fuel cap,
making sure to fully install the cap. See
Filling Your
Tank on page 5-9. The diganostic system can determine
if the fuel cap has been left off or improperly installed.
A loose or missing fuel cap will allow fuel to evaporate
into the atmosphere. A few driving trips with the cap
properly installed should turn the light and message off.
3-70

Making Turns
Notice:Making very sharp turns while trailering
could cause the trailer to come in contact with the
vehicle. Your vehicle could be damaged. Avoid
making very sharp turns while trailering.
When you're turning with a trailer, make wider turns
than normal. Do this so your trailer won't strike
soft shoulders, curbs, road signs, trees or other objects.
Avoid jerky or sudden maneuvers. Signal well in
advance.
Turn Signals When Towing a Trailer
The arrows on your instrument panel will ¯ash whenever
you signal a turn or lane change. Properly hooked up,
the trailer lamps will also ¯ash, telling other drivers
you're about to turn, change lanes or stop.
When towing a trailer, the arrows on your instrument
panel will ¯ash for turns even if the bulbs on the trailer
are burned out. Thus, you may think drivers behind
you are seeing your signal when they are not. It's
important to check occasionally to be sure the trailer
bulbs are still working.
Driving On Grades
Reduce speed and shift to a lower gearbeforeyou start
down a long or steep downgrade. If you don't shift
down, you might have to use your brakes so much that
they would get hot and no longer work well.
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).
You may also want to activate the tow/haul mode if the
transmission shifts too often. See ªTow/Haul Modeº
for more information.
When towing at high altitude on steep uphill grades,
consider the following: Engine coolant will boil at a lower
temperature than at normal altitudes. If you turn your
engine off immediately after towing at high altitude
on steep uphill grades, your vehicle may show signs
similar to engine overheating. To avoid this, let the
engine run while parked (preferably on level ground)
with the automatic transmission in PARK (P) for a
few minutes before turning the engine off. If you do get
the overheat warning, see
Engine Overheating on
page 5-33.
4-75

Service............................................................5-3
Doing Your Own Service Work.........................5-3
Adding Equipment to the Outside
of Your Vehicle...........................................5-4
Fuel................................................................5-4
Gasoline Octane............................................5-5
Gasoline Speci®cations....................................5-5
California Fuel...............................................5-6
Additives.......................................................5-6
Fuel E-85 (85% Ethanol).................................5-7
Fuels in Foreign Countries...............................5-8
Filling Your Tank............................................5-9
Filling a Portable Fuel Container.....................5-11
Checking Things Under
the Hood....................................................5-12
Hood Release..............................................5-12
Engine Compartment Overview.......................5-14
Engine Oil...................................................5-18
Engine Air Cleaner/Filter................................5-23
Automatic Transmission Fluid.........................5-26
Engine Coolant.............................................5-29
Coolant Surge Tank Pressure Cap..................5-32
Engine Overheating.......................................5-33Cooling System............................................5-36
Engine Fan Noise.........................................5-42
Power Steering Fluid.....................................5-43
Windshield Washer Fluid................................5-44
Brakes........................................................5-45
Battery........................................................5-48
Jump Starting...............................................5-49
All-Wheel Drive..............................................5-55
Rear Axle.......................................................5-56
Four-Wheel Drive............................................5-57
Front Axle......................................................5-58
Bulb Replacement..........................................5-59
Halogen Bulbs..............................................5-59
Headlamps..................................................5-60
Front Turn Signal, Sidemarker and Daytime
Running Lamps.........................................5-61
Side Identi®cation Marker Lamps.....................5-62
Roof Marker Lamps......................................5-62
Taillamps.....................................................5-64
Replacement Bulbs.......................................5-66
Windshield Wiper Blade Replacement..............5-66
Section 5 Service and Appearance Care
5-1

How to Add Fluid
Refer to the Maintenance Schedule to determine what
kind of transmission ¯uid to use. SeePart D:
Recommended Fluids and Lubricants on page 6-18.
Add ¯uid only after checking the transmission ¯uid while
it is hot. (A cold check is used only as a reference.) If
the ¯uid level is low, add only enough of the proper ¯uid
to bring the level up to the HOT area for a hot check.
It doesn't take much ¯uid, generally less than one
pint (0.5 L).
Don't over®ll.
Notice:
We recommend you use only ¯uid labeled
DEXRONž-III, because ¯uid with that label is
made especially for your automatic transmission.
Damage caused by ¯uid other than DEXRON
ž-III is
not covered by your new vehicle warranty.
·After adding ¯uid, recheck the ¯uid level as
described under
How to Check.
·When the correct ¯uid level is obtained, push the
dipstick back in all the way; then ¯ip the handle
down to lock the dipstick in place.
Engine Coolant
The cooling system in your vehicle is ®lled with
DEX-COOLžengine coolant. This coolant is designed
to remain in your vehicle for 5 years or 150,000 miles
(240 000 km), whichever occurs ®rst, if you add only
DEX-COOL
žextended life coolant.
The following explains your cooling system and how to
add coolant when it is low. If you have a problem
with engine overheating, see
Engine Overheating on
page 5-33.
5-29

Adding Coolant
If you need more coolant, add the proper DEX-COOLž
coolant mixtureat the surge tank, but only when the
engine is cool.
{CAUTION:
You can be burned if you spill coolant on hot
engine parts. Coolant contains ethylene glycol,
and it will burn if the engine parts are hot
enough. Don't spill coolant on a hot engine.
When replacing the pressure cap, make sure it is
hand-tight.
Coolant Surge Tank Pressure Cap
SeeEngine Compartment
Overview on page 5-14for
more information on
location.
The coolant surge tank pressure cap must be fully
installed on the coolant surge tank.
Notice:Your pressure cap is a pressure-type cap
and must be tightly installed to prevent coolant loss
and possible engine damage from overheating.
See ªCapacities and Speci®cationsº for more
information.
5-32