2003 CHEVROLET TAHOE brake

Basic Trailer Wiring
The trailer wiring harness, with a seven-pin connector,
is located at the rear of the vehicle and is tied to
the vehicle's frame. The harness connector can be
plugged into a seven-pin universal heavy-duty trailer
connector available through your dealer.The seven-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
·Red: Battery Feed
·Dark Blue: Trailer Brake
4-78

Heavy-Duty Trailer Wiring Harness
Package
Your vehicle is equipped with the seven-wire trailer
towing harness. This harness with a seven-pin universal
trailer connector is attached to a bracket on the hitch
platform.The seven-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
·Red: Battery Feed
·Dark Blue: Trailer Brake
If your trailer is equipped with electronic brakes, you
can get a jumper harness (electric trailer brake control)
with a trailer battery feed fuse from your dealer. This
harness and fuse should be installed by your dealer or a
quali®ed service center.
If you need to tow a light-duty trailer with a standard
four-way round pin connector, you can also get an
adapter.
4-79

Instrument Panel Jumper Wiring Harness
This harness is included with your vehicle as part of the
heavy-duty trailer wiring package.
This harness is for an electric brake controller and
includes a trailer battery feed fuse. It should be installed
by your dealer or a quali®ed service center.
This harness is new for your vehicle, and you will not be
able to use a harness from an earlier model year.
Four-Wire Harness Adapter
This adapter is included
with your vehicle as part of
the heavy-duty trailer
wiring package.
Use this adapter to connect a standard four-way round
pin connector to the seven-wire harness on your
vehicle.
4-80

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

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 inside
the vehicle located
under and to the left of
the steering wheel.
5-12

A. Engine Air Cleaner/Filter. SeeEngine Air
Cleaner/Filter on page 5-23.
B. Coolant Surge Tank. See
Cooling System on
page 5-36.
C. Air Filter Restriction Indicator (If Equipped). See
Engine Air Cleaner/Filter on page 5-23.
D. Engine Oil Dipstick. See
Engine Oil on page 5-18.
E. Automatic Transmission Dipstick. See
Automatic
Transmission Fluid on page 5-26.
F. Engine Oil Fill. See
Engine Oil on page 5-18.
G. Fan. See
Cooling System on page 5-36.
H. Remote Negative (-) Terminal (GND). See
Jump
Starting on page 5-49.I. Power Steering Fluid Reservoir. See
Power Steering
Fluid on page 5-43.
J. Remote Positive (+) Terminal. See
Jump Starting on
page 5-49.
K. Brake Master Cylinder Reservoir. See
Brakes on
page 5-45.
L. Underhood Fuse Block. See
Fuses and Circuit
Breakers on page 5-109.
M. Battery. See
Battery on page 5-48.
N. Windshield Washer Fluid Reservoir. See
Windshield
Washer Fluid on page 5-44.
5-15

A. Engine Air Cleaner/Filter. SeeEngine Air
Cleaner/Filter on page 5-23.
B. Coolant Surge Tank. See
Cooling System on
page 5-36.
C. Air Filter Restriction Indicator (If Equipped). See
Engine Air Cleaner/Filter on page 5-23.
D. Engine Oil Dipstick. See
Engine Oil on page 5-18.
E. Automatic Transmission Dipstick. See
Automatic
Transmission Fluid on page 5-26.
F. Engine Oil Fill. See
Engine Oil on page 5-18.
G. Fan. See
Cooling System on page 5-36.
H. Remote Negative (-) Terminal (GND). See
Jump
Starting on page 5-49.I. Remote Positive (+) Terminal. See
Jump Starting on
page 5-49.
J. Power Steering Fluid Reservoir. See
Power Steering
Fluid on page 5-43.
K. Brake Master Fluid Reservoir. See
Brakes on
page 5-45.
L. Underhood Fuse Block. See
Fuses and Circuit
Breakers on page 5-109.
M. Battery. See
Battery on page 5-48.
N. Windshield Washer Fluid Reservoir. See
Windshield
Washer Fluid on page 5-44.
5-17

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.
5-27