GMC SONOMA 2003 Owner's Manual

Two-Piece Front Turn Signal Lamps
1. Remove the headlamp assembly as shown in
″Two-Piece Composite Headlamp System″
underHeadlamps on page 5-50.
2. Locate the locking
tabs on the assembly.
Squeeze the tabs
together and push that
end of the assembly
out while holding
the tabs. The assembly
will swing out.3. Unplug the electrical connector.
4. Turn the harness bulb socket counterclockwise to
remove it. Pull the bulb straight out to remove it
from the socket.
5. Push the new bulb into the socket until it snaps
into place.
6. Put the socket into the lamp assembly and turn it
clockwise until it is tight.
7. To reinstall the assembly, snap the outboard end of
the lamp assembly back into the vehicle. Then
swing the assembly in and snap it into place.
8. Install the two retaining clips.
9. Close the hood.
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Center High-Mounted Stoplamp
(CHMSL)
1. Remove the lens retaining screws.
2. Remove the lens.3. Remove the bulb.
4. Install a new bulb.
5. Reinstall the lens and tighten the screws.
If equipment such as a cap or camper is installed on
your vehicle, a center high-mounted stoplamp feed wire
is provided along the driver’s side rear frame. This
wire should be used to install a center high-mounted
stoplamp in the cap or camper.
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Taillamps
1. Open the tailgate.
2. Remove the screws
from the lamp
assembly near the
tailgate latch.
3. Pull the assembly away from the pickup side panel.
4. Turn the socket counterclockwise to remove it.
Push the tab in while you turn the socket.
5. Pull the bulb out.
6. Push the new bulb into the socket.
7. Put the socket into the assembly and turn the
socket clockwise until it locks in place.
8. Reinstall the assembly. Install and tighten the
screws.
9. Close the tailgate.
Replacement Bulbs
Exterior Lamp Bulb Number
Halogen Headlamps
Composite Low-Beam
Composite High-Beam9006 HB4 or
9006 LL
9005 HB3
Tail and Stoplamps 3057
Rear Sidemarker Lamps 194
Front Sidemarker Lamps 194NA
Front Turn Signal Lamps 3457A
Center High–Mounted Stoplamp 211–2
*For replacement bulbs not listed here,
please consult your dealer.
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Windshield Wiper Blade
Replacement
Windshield wiper blades should be inspected at least
twice a year for wear and cracking. See“Wiper
Blade Check”underAt Least Twice a Year on
page 6-26.
Replacement blades come in different types and are
removed in different ways. For proper type and length,
seeNormal Maintenance Replacement Parts on
page 5-96.
Notice:Use care when removing or installing a
blade assembly. Accidental bumping can cause the
arm to fall back and strike the windshield.
1. To remove the old wiper blades, lift the wiper arm
until it locks into a vertical position.
A. Blade Assembly
B. Arm Assembly
C. Locking TabD. Blade Pivot
E. Hook Slot
F. Arm Hook
2. Press down on the blade assembly pivot locking
tab. Pull down on the blade assembly to release it
from the wiper arm hook.
3. Remove the insert from the blade assembly. The
insert has two notches at one end that are locked by
bottom claws of the blade assembly. At the notched
end, pull the insert from the blade assembly.
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4. To install the new wiper insert, slide the insert (D),
notched end last, into the end with two blade
claws (A). Slide the insert all the way through the
blade claws at the opposite end (B). The plastic
caps (C) will be forced off as the insert is fully
inserted.
5. Be sure that the notches are locked by the bottom
claws. Make sure that all other claws are properly
locked on both sides of the insert slots.A. Claw in Notch
B. Correct Installation
C. Incorrect Installation
6. Put the blade assembly pivot in the wiper arm hook.
Pull up until the pivot locking tab locks in the
hook slot.
7. Carefully lower the wiper arm and blade assembly
onto the windshield.
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Tires
Your new vehicle comes with high-quality tires made by
a leading tire manufacturer. If you ever have questions
about your tire warranty and where to obtain service,
see your GMC Warranty booklet for details.
{CAUTION:
Poorly maintained and improperly used tires
are dangerous.
Overloading your tires can cause
overheating as a result of too much
friction. You could have an air-out and a
serious accident. See“Loading Your
Vehicle”in the Index.
Underinated tires pose the same danger
as overloaded tires. The resulting accident
could cause serious injury. Check all tires
frequently to maintain the recommended
pressure. Tire pressure should be checked
when your tires are cold.
CAUTION: (Continued)
CAUTION: (Continued)

Overinated tires are more likely to be
cut, punctured or broken by a sudden
impact—such as when you hit a pothole.
Keep tires at the recommended pressure.
Worn, old tires can cause accidents. If
your tread is badly worn, or if your tires
have been damaged, replace them.
Ination–Tire Pressure
The Certification/Tire label, which is on the driver’s door
edge, above the door latch, shows the correct inflation
pressures for your tires when they’re cold.“Cold”means
your vehicle has been sitting for at least three hours
or driven no more than 1 mile (1.6 km).
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Notice:Don’t let anyone tell you that underination
or overination is all right. It’s not. If your tires
don’t have enough air (underination), you can get
the following:
Too muchexing
Too much heat
Tire overloading
Bad wear
Bad handling
Bad fuel economy
If your tires have too much air (overination),
you can get the following:
Unusual wear
Bad handling
Rough ride
Needless damage from road hazards
When to Check
Check your tires once a month or more.
Also, check the tire pressure of the spare tire.
If you have a compact spare tire, it should be
at 60 psi (420 kPa).
How to Check
Use a good quality pocket-type gage to check tire
pressure. You can’t tell if your tires are properly inflated
simply by looking at them. Radial tires may look
properly inflated even when they’re underinflated.
Be sure to put the valve caps back on the valve stems.
They help prevent leaks by keeping out dirt and moisture.
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Tire Inspection and Rotation
Tires should be rotated every 6,000 to 8,000 miles
(10 000 to 13 000 km).
Any time you notice unusual wear, rotate your tires as
soon as possible and check wheel alignment. Also
check for damaged tires or wheels. SeeWhen It Is Time
for New Tires on page 5-61andWheel Replacement
on page 5-65for more information.
Make sure the spare tire is stored securely. Push, pull,
and then try to rotate or turn the tire. If it moves,
use the wheel wrench to tighten the cable. See
Changing a Flat Tire on page 5-68.
The purpose of regular rotation is to achieve more
uniform wear for all tires on the vehicle. Thefirst rotation
is the most important. See“Part A: Scheduled
Maintenance Services,”in Section 6, for scheduled
rotation intervals.When rotating your tires, always use one of the correct
rotation patterns shown here.
If your vehicle has a compact spare tire or a spare tire
that does not match your vehicle’s regular road tires
and wheels in size and type, do not include the spare
in the tire rotation.
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After the tires have been rotated, adjust the front and
rear inflation pressures as shown on the
Certification/Tire label. Make certain that all wheel nuts
are properly tightened. See“Wheel Nut Torque”
underCapacities and Specifications on page 5-94.
{CAUTION:
Rust or dirt on a wheel, or on the parts to
which it is fastened, can make wheel nuts
become loose after a time. The wheel could
come off and cause an accident. When you
change a wheel, remove any rust or dirt from
places where the wheel attaches to the vehicle.
In an emergency, you can use a cloth or a
paper towel to do this; but be sure to use a
scraper or wire brush later, if you need to,
to get all the rust or dirt off. See“Changing a
Flat Tire”in the Index.
When It Is Time for New Tires
One way to tell when it’s
time for new tires is to
check the treadwear
indicators, which will
appear when your tires
have only 1/16 inch
(1.6 mm) or less of tread
remaining. Some
commercial truck tires
may not have treadwear
indicators.
You need a new tire if any of the following statements
are true:
•You can see the indicators at three or more places
around the tire.
•You can see cord or fabric showing through the
tire’s rubber.
•The tread or sidewall is cracked, cut or snagged
deep enough to show cord or fabric.
•The tire has a bump, bulge or split.
•The tire has a puncture, cut or other damage that
can’t be repaired well because of the size or
location of the damage.
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Buying New Tires
Tofind out what kind and size of tires you need,
look at the Certification/Tire label.
The tires installed on your vehicle when it was new had
a Tire Performance Criteria Specification (TPC Spec)
number on each tire’s sidewall. When you get new tires,
get ones with that same TPC Spec number. That way
your vehicle will continue to have tires that are designed
to give proper endurance, handling, speed rating,
traction, ride and other things during normal service on
your vehicle. If your tires have an all-season tread
design, the TPC number will be followed by an“MS”
(for mud and snow).
If you ever replace your tires with those not having a
TPC Spec number, make sure they are the same size,
load range, speed rating and construction type
(bias, bias-belted or radial) as your original tires.{CAUTION:
Mixing tires could cause you to lose control
while driving. If you mix tires of different sizes
or types (radial and bias-belted tires), the
vehicle may not handle properly, and you
could have a crash. Using tires of different
sizes may also cause damage to your vehicle.
Be sure to use the same size and type tires on
all wheels. It’s all right to drive with your
compact spare (if you have one). It was
developed for use on your vehicle.
{CAUTION:
If you use bias-ply tires on your vehicle, the
wheel rimanges could develop cracks after
many miles of driving. A tire and/or wheel
could fail suddenly, causing a crash. Use only
radial-ply tires with the wheels on your vehicle.
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