2003 CHEVROLET AVALANCHE brake

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
earlier in this section.
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 5-27.
Parking on Hills
{CAUTION:
You really should not park your vehicle, with a
trailer attached, on a hill. If something goes
wrong, your rig could start to move. People
can be injured, and both your vehicle and the
trailer can be damaged.
But if you ever have to park your rig on a hill, here's
how to do it:
1. Apply your regular brakes, but don't shift into
PARK (P) yet.
2. Have someone place chocks under the trailer
wheels.
3. When the wheel chocks are in place, release the
regular brakes until the chocks absorb the load.
4. Reapply the regular brakes. Then apply your
parking brake and shift into PARK (P).
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5. If you have a four-wheel-drive vehicle, be sure the
transfer case is in a drive gear and not in
NEUTRAL (N).
6. Release the regular brakes.
{CAUTION:
It can be dangerous to get out of your vehicle
if the shift lever is not fully in PARK (P) with
the parking brake ®rmly set. Your vehicle can
roll.
If you have left the engine running, the vehicle
can move suddenly. You or others could be
injured. To be sure your vehicle won't move,
even when you're on fairly level ground, use
the steps that follow.
Always put the shift lever fully in PARK (P)
with the parking brake ®rmly set.
If the transfer case on four-wheel-drive
vehicles is in NEUTRAL, your vehicle will be
free to roll, even if your shift lever is in PARK
(P). So, be sure the transfer case is in a drive
gear Ð not in NEUTRAL.
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 ¯uid (don't over®ll),
engine oil, axle lubricant, belts, cooling system and
brake system. Each of these is covered in this manual,
and the Index will help you ®nd 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.
4-67

Trailer Wiring Harness
Heavy-Duty Trailer Wiring Package
Your vehicle is equipped with the eight-wire trailer
towing harness. This harness with a seven-pin universal
heavy-duty trailer connector is attached to a bracket
on the hitch platform.The Center High-Mounted Stoplamp (CHMSL) wire is
tied next to the trailer wiring harness for use with a
trailer.
The eight-wire harness contains the following trailer
circuits:
·Yellow: Left Stop/Turn Signal
·Dark Green: Right Stop/Turn Signal
·Brown: Taillamps
·White: Ground
·Light Green: Back-up Lamps
·Light Blue: CHMSL
·Red: Battery Feed
·Dark Blue: Trailer Brake
If your trailer is equipped with electric brakes, you can
get a jumper harness (electric trailer brake control)
with a trailer battery feed fuse from your dealer. If you
need to tow a light-duty trailer with a standard four-way
round connector you can also get an adaptor from
your dealer.
4-68

Service............................................................5-3
Doing Your Own Service Work.........................5-4
Adding Equipment to the Outside of Your
Vehicle......................................................5-4
Fuel................................................................5-5
Gasoline Octane............................................5-5
Gasoline Speci®cations....................................5-5
California Fuel...............................................5-6
Additives.......................................................5-6
Fuels in Foreign Countries...............................5-7
Filling Your Tank............................................5-7
Filling a Portable Fuel Container.......................5-9
Checking Things Under the Hood....................5-10
Hood Release..............................................5-10
Engine Compartment Overview.......................5-12
Engine Oil...................................................5-15
Engine Air Cleaner/Filter................................5-20
Automatic Transmission Fluid.........................5-22
Engine Coolant.............................................5-24
Coolant Surge Tank Pressure Cap..................5-27
Engine Overheating.......................................5-27
Cooling System............................................5-30
Engine Fan Noise.........................................5-36Power Steering Fluid.....................................5-36
Windshield Washer Fluid................................5-38
Brakes........................................................5-39
Battery........................................................5-42
Jump Starting...............................................5-43
Rear Axle.......................................................5-49
Four-Wheel Drive............................................5-50
Front Axle......................................................5-51
Bulb Replacement..........................................5-52
Halogen Bulbs..............................................5-52
Headlamps..................................................5-52
Front Turn Signal, Sidemarker and Parking
Lamps.....................................................5-55
Front Turn Signal, Sidemarker and Daytime
Running Lamps.........................................5-56
Daytime Running Lamps................................5-58
Center High-Mounted Stoplamp (CHMSL).........5-58
Taillamps.....................................................5-58
Replacement Bulbs.......................................5-59
Windshield Wiper Blade Replacement..............5-60
Section 5 Service and Appearance Care
5-1

Checking Things Under the
Hood
{CAUTION:
Things that burn can get on hot engine parts
and start a ®re. These include liquids like fuel,
oil, coolant, brake ¯uid, windshield washer and
other ¯uids, and plastic or rubber. You or
others could be burned. Be careful not to drop
or spill things that will burn onto a hot engine.
Hood Release
To open the hood, do the following:
1. Pull the handle located
inside the vehicle to
the lower left of
the steering wheel.
5-10

A. Engine Air Cleaner/Filter. SeeEngine Air
Cleaner/Filter on page 5-20.
B. Coolant Surge Tank. See
Cooling System on
page 5-30andCoolant Surge Tank Pressure Cap
on page 5-27.
C. Air Filter Restriction Indicator (If Equipped). See
Engine Air Cleaner/Filter on page 5-20.
D. Engine Oil Fill. See
Engine Oil on page 5-15.
E. Engine Oil Dipstick. See
Engine Oil on page 5-15.
F. Automatic Transmission Dipstick. See
Automatic
Transmission Fluid on page 5-22.
G. Fan. See
Cooling System on page 5-30andEngine
Fan Noise on page 5-36.H. Remote Negative (-) Terminal (GND). See
Jump
Starting on page 5-43.
I. Power Steering Fluid Reservoir (Out of View). See
Power Steering Fluid on page 5-36.
J. Remote Positive (+) Terminal. See
Jump Starting on
page 5-43.
K. Brake Fluid Reservoir. See
Brakes on page 5-39.
L. Underhood Fuse Block. See ªUnderhood Fuse Blockº
under
Fuses and Circuit Breakers on page 5-97.
M. Battery. See
Battery on page 5-42.
N. Windshield Washer Fluid Reservoir. See
Windshield
Washer Fluid on page 5-38.
5-13

A. Engine Air Cleaner/Filter. SeeEngine Air
Cleaner/Filter on page 5-20.
B. Coolant Surge Tank. See
Cooling System on
page 5-30andCoolant Surge Tank Pressure Cap
on page 5-27.
C. Air Filter Restriction Indicator (If Equipped). See
Engine Air Cleaner/Filter on page 5-20.
D. Engine Oil Dipstick. See
Engine Oil on page 5-15.
E. Automatic Transmission Dipstick. See
Automatic
Transmission Fluid on page 5-22.
F. Engine Oil Fill. See
Engine Oil on page 5-15.
G. Fan. See
Cooling System on page 5-30andEngine
Fan Noise on page 5-36.
H. Remote Negative (-) Terminal (GND). See
Jump
Starting on page 5-43.
I. Remote Positive (+) Terminal. See
Jump Starting on
page 5-43.
J. Power Steering Fluid Reservoir. See
Power Steering
Fluid on page 5-36.
K. Brake Fluid Reservoir. See
Brakes on page 5-39.
L. Underhood Fuse Block. See ªUnderhood Fuse Blockº
under
Fuses and Circuit Breakers on page 5-97.
M. Battery. See
Battery on page 5-42.
N. Windshield Washer Fluid Reservoir. See
Windshield
Washer Fluid on page 5-38.
Engine Oil
If the CHECK OIL LEVEL light appears on the
instrument cluster, it means you need to check your
engine oil level right away.
For more information, see ªCHECK OIL LEVELº under
DIC Warnings and Messages on page 3-57.
You should check your engine oil level regularly; this is
an added reminder.
Checking Engine Oil
It's a good idea to check your engine oil every time you
get fuel. In order to get an accurate reading, the oil
must be warm and the vehicle must be on level ground.
The engine oil dipstick has
a ring handle and is
located on the passenger's
side of the vehicle. See
Engine Compartment
Overview on page 5-12for
more information on
location.
5-15

Get the vehicle warmed up by driving about 15 miles
(24 km) when outside temperatures are above 50ÉF
(10ÉC). If it's colder than 50ÉF (10ÉC), 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
50ÉF (10ÉC) or more. If it's colder than 50ÉF (10ÉC), you
may have to idle the engine longer. Should the ¯uid
level be low during this cold check, you
mustcheck the
¯uid hot before adding ¯uid. Checking the ¯uid hot
will give you a more accurate reading of the ¯uid level.
Checking the Fluid Level
Prepare your vehicle as follows:
·Park your vehicle on a level place. Keep the engine
running.
·With the parking brake applied, place the shift lever
in PARK (P).
·With your foot on the brake pedal, move the shift
lever through each gear range, pausing for about
three seconds in each range. Then, position the shift
lever in PARK (P).
·Let the engine run at idle for three minutes or more.Then, without shutting off the engine, follow these steps:
The transmission dipstick
handle with the graphic is
located at the rear of
the engine compartment,
on the passenger's side.
See
Engine Compartment Overview on page 5-12for
more information on location.
1. Flip the handle up and then pull out the dipstick
and wipe it with a clean rag or paper towel.
2. Push it back in all the way, wait three seconds and
then pull it back out again.
5-23