light CHEVROLET IMPALA 2003 8.G Repair Manual

Radiator Pressure Cap
Notice:Your radiator cap is a pressure-type cap
and must be tightly installed to prevent coolant loss
and possible engine damage from overheating.
Be sure the arrows on the cap line up with the
over¯ow tube on the radiator ®ller neck.
The radiator pressure cap is located in the front of the
engine compartment on the passenger's side, near
the diagonal cross brace. See
Engine Compartment
Overview on page 5-12for more information on location.
Engine Overheating
You will ®nd a coolant temperature gage and a warning
message about a hot engine on your instrument
panel cluster. See
Engine Coolant Temperature Gage
on page 3-36andHot Coolant Temperature Warning
Message on page 3-42.
Overheated Engine Protection
Operating Mode
This emergency operating mode allows your vehicle to
be driven to a safe place in an emergency situation.
If an overheated engine condition exists, an overheat
protection mode which alternates ®ring groups of
cylinders helps prevent engine damage. In this mode,
you will notice a signi®cant loss in power and engine
performance. The low coolant light may come on
and the temperature gage will indicate an overheat
condition exists. Driving extended miles (km) and/or
towing a trailer in the overheat protection mode should
be avoided.
Notice:After driving in the overheated engine
protection operating mode, to avoid engine damage,
allow the engine to cool before attempting any
repair. The engine oil will be severely degraded.
Repair the cause of coolant loss, change the oil
and reset the oil life system. See ªEngine Oilº in
the Index.
5-30

There are only two reasons why the brake ¯uid level in
the reservoir might go down. The ®rst is that the
brake ¯uid goes down to an acceptable level during
normal brake lining wear. When new linings are put in,
the ¯uid level goes back up. The other reason is
that ¯uid is leaking out of the brake system. If it is, you
should have your brake system ®xed, since a leak
means that sooner or later your brakes won't work well,
or won't work at all.
So, it isn't a good idea to ªtop offº your brake ¯uid.
Adding brake ¯uid won't correct a leak. If you add ¯uid
when your linings are worn, then you'll have too
much ¯uid when you get new brake linings. You should
add (or remove) brake ¯uid, as necessary, only when
work is done on the brake hydraulic system.
{CAUTION:
If you have too much brake ¯uid, it can spill on
the engine. The ¯uid will burn if the engine is
hot enough. You or others could be burned,
and your vehicle could be damaged. Add brake
¯uid only when work is done on the brake
hydraulic system.When your brake ¯uid falls to a low level, your brake
warning light will come on. See
Brake System Warning
Light on page 3-34.
What to Add
When you do need brake ¯uid, use only DOT-3 brake
¯uid. Use new brake ¯uid from a sealed container
only. See
Part D: Recommended Fluids and Lubricants
on page 6-16.
Always clean the brake ¯uid reservoir cap and the area
around the cap before removing it. This will help
keep dirt from entering the reservoir.
{CAUTION:
With the wrong kind of ¯uid in your brake
system, your brakes may not work well, or
they may not even work at all. This could
cause a crash. Always use the proper brake
¯uid.
5-46

Notice:
·Using the wrong ¯uid can badly damage brake
system parts. For example, just a few drops of
mineral-based oil, such as engine oil, in your
brake system can damage brake system
parts so badly that they'll have to be replaced.
Don't let someone put in the wrong kind of ¯uid.
·If you spill brake ¯uid on your vehicle's painted
surfaces, the paint ®nish can be damaged. Be
careful not to spill brake ¯uid on your vehicle. If
you do, wash it off immediately. See
ªAppearance Careº in the Index.
Brake Wear
Your vehicle has four-wheel disc brakes.
Disc brake pads have built-in wear indicators that make
a high-pitched warning sound when the brake pads
are worn and new pads are needed. The sound
may come and go or be heard all the time your vehicle
is moving (except when you are pushing on the
brake pedal ®rmly).
{CAUTION:
The brake wear warning sound means that
soon your brakes won't work well. That could
lead to an accident. When you hear the brake
wear warning sound, have your vehicle
serviced.
Notice:Continuing to drive with worn-out brake
pads could result in costly brake repair.
Some driving conditions or climates may cause a brake
squeal when the brakes are ®rst applied or lightly
applied. This does not mean something is wrong with
your brakes.
Properly torqued wheel nuts are necessary to help
prevent brake pulsation. When tires are rotated, inspect
brake pads for wear and evenly tighten wheel nuts in
the proper sequence to GM torque speci®cations.
Brake linings should always be replaced as complete
axle sets.
See
Brake System Inspection on page 6-15.
5-47

Notice:Ignoring these steps could result in costly
damage to your vehicle that wouldn't be covered
by your warranty.
Trying to start your vehicle by pushing or pulling it
won't work, and it could damage your vehicle.
Notice:If the other system isn't a 12-volt system
with a negative ground, both vehicles can be
damaged.
1. Check the other vehicle. It must have a 12±volt
battery with a negative ground system.
2. Get the vehicles close enough so the jumper cables
can reach, but be sure the vehicles aren't touching
each other. If they are, it could cause a ground
connection you don't want. You wouldn't be able to
start your vehicle, and the bad grounding could
damage the electrical systems.
To avoid the possibility of the vehicles rolling, set
the parking brake ®rmly on both vehicles involved in
the jump start procedure. Put an automatic
transaxle in PARK (P) or a manual transaxle in
NEUTRAL before setting the parking brake.
Notice:If you leave your radio on, it could be badly
damaged. The repairs wouldn't be covered by
your warranty.
3. Turn off the ignition on both vehicles. Unplug
unnecessary accessories plugged into the cigarette
lighter or in the accessory power outlets. Turn off
the radio and all lamps that aren't needed. This will
avoid sparks and help save both batteries. And it
could save your radio!
4. Open the hoods and locate the batteries. Find the
positive (+) and negative (-) terminal locations on
each vehicle.
You will not need to access your battery for jump
starting. Your vehicle has a remote positive (+) jump
starting terminal for that purpose. The remote
positive (+) terminal is located in the engine
compartment on the passenger's side of the vehicle,
next to the upper underhood fuse block. See
Engine Compartment Overview on page 5-12for
more information on location.
5-50

To uncover the remote positive (+) terminal, lift the
plastic cap. You should always use the remote
positive (+) terminal instead of the positive (+)
terminal on the battery.
{CAUTION:
An electric fan can start up even when the
engine is not running and can injure you. Keep
hands, clothing and tools away from any
underhood electric fan.
{CAUTION:
Using a match near a battery can cause battery
gas to explode. People have been hurt doing
this, and some have been blinded. Use a
¯ashlight if you need more light.
Be sure the battery has enough water. You
don't need to add water to the ACDelco
ž
battery installed in your new vehicle. But if a
battery has ®ller caps, be sure the right
amount of ¯uid is there. If it is low, add water
to take care of that ®rst. If you don't, explosive
gas could be present.
Battery ¯uid contains acid that can burn you.
Don't get it on you. If you accidentally get it in
your eyes or on your skin, ¯ush the place with
water and get medical help immediately.
5-51

Uniform Tire Quality Grading
Quality grades can be found where applicable on the
tire sidewall between tread shoulder and maximum
section width. For example:
Treadwear 200 Traction AA Temperature A
The following information relates to the system
developed by the United States National Highway
Traffic Safety Administration, which grades tires by
treadwear, traction and temperature performance. (This
applies only to vehicles sold in the United States.)
The grades are molded on the sidewalls of most
passenger car tires. The Uniform Tire Quality Grading
system does not apply to deep tread, winter-type
snow tires, space-saver or temporary use spare tires,
tires with nominal rim diameters of 10 to 12 inches
(25 to 30 cm), or to some limited-production tires.
While the tires available on General Motors passenger
cars and light trucks may vary with respect to these
grades, they must also conform to federal safety
requirements and additional General Motors Tire
Performance Criteria (TPC) standards.
Treadwear
The treadwear grade is a comparative rating based on
the wear rate of the tire when tested under controlled
conditions on a speci®ed government test course.
For example, a tire graded 150 would wear one and
a half (1.5) times as well on the government course as
a tire graded 100. The relative performance of tires
depends upon the actual conditions of their use,
however, and may depart signi®cantly from the norm
due to variations in driving habits, service practices and
differences in road characteristics and climate.
Traction ± AA, A, B, C
The traction grades, from highest to lowest, are AA, A,
B, and C. Those grades represent the tire's ability
to stop on wet pavement as measured under controlled
conditions on speci®ed government test surfaces of
asphalt and concrete. A tire marked C may have poor
traction performance. Warning: The traction grade
assigned to this tire is based on straight-ahead braking
traction tests, and does not include acceleration,
cornering, hydroplaning, or peak traction characteristics.
5-68

Vehicle Care/Appearance Materials
(cont'd)
Description Usage
Finish EnhancerRemoves dust,
®ngerprints, and surface
contaminants. Spray on
wipe off.
Swirl Remover PolishRemoves swirl marks,
®ne scratches and other
light surface
contamination.
Cleaner WaxRemoves light scratches
and protects ®nish.
Foaming Tire Shine Low
GlossCleans, shines and
protects in one easy step,
no wiping necessary.
Wash Wax ConcentrateMedium foaming
shampoo. Cleans and
lightly waxes.
Biodegradable and
phosphate free.
Vehicle Care/Appearance Materials
(cont'd)
Description Usage
Spot LifterQuickly and easily
removes spots and stains
from carpets, vinyl and
cloth upholstery.
Odor EliminatorOdorless spray odor
eliminator used on
fabrics, vinyl, leather and
carpet.
See your General Motors parts department for these
products. See
Part D: Recommended Fluids and
Lubricants on page 6-16.
5-92

Fuses Usage
PCM/BCM/
CLSTRPowertrain Control Module, Body
Control Module, Cluster (Ignition 0)
WSWWindshield Wipers, Windshield
Washer
PCM (CRANK) Powertrain Control Module (Crank)
CIG/AUX Accommodated Device (Accessory)
BCM Body Control Module (Accessory)
SRS Supplemental Restraint System
ABS/PCM Anti-Lock Brake System, Powertrain
Control Module, Brake Switch,
Crank Relay, Canister Vent Solenoid
(Run, Crank)
STOPBrake Lamps, Body Control Module
(Run, Crank)
TURN SIGNAL Turn Signal Flashers
CRUISECruise Control Steering Column
Controls
AC/CRUISEHVAC Temp Door Motors & Module,
Cruise Control Module
A/C FAN HVAC Blower
STR COL Steering Wheel LightingFuses Usage
DR LKBody Control Module, Door Lock
Controls
PWR MIR Power Mirrors
CLSTR/BCMCluster, Body Control Module, Data
Link Connector (Battery)
LH HTD
ST/BCMDriver's Heated Seat, Body Control
Module, Battery Controlled Loads
Circuit
BreakersUsage
RETAINED
ACCESSORY
PWR BRKRPower Window, Sunroof Breaker
Relays Usage
HEADLAMP
RELAYHeadlamp Relay
RETAINED
ACCESSORY
PWR RELAYRetained Accessory Power Relay
5-97

Fuses Usage
RH HTD ST Passenger Heated Seat
PWR DROP Accommodated Device
B/U LP Back-Up Lamps
DIC/RKEDriver Information Center, Remote
Keyless Entry, HVAC
TRK/ROOF
BRPTrunk Lamps, Headliner Lamps
HVAC BLO HVAC Blower Relay
I/P BRP Instrument Panel Footwell Lamps
HTD MIR Heated Mirrors
BRK SW Brake Switch
HAZ SW Hazard Switch
REAR PRK LP Rear Parking Lamps
AUX PWR Accessory Power Outlet (Battery)
C/LTR Cigarette Lighter
RADIORadio, Radio Ampli®er, Remote
Digital Radio Receiver
FRT PARK LPFront Parking Lamps,
Instrumentation LightingRelays Usage
PARK LP
RELAYParking Lamps Relay
BACK UP LP
RELAYBack-up Lamps Relay
BATT RUN
DOWN
PROTECTION
RELAYBattery Run Down Protection Relay
REAR DEFOG
RELAYRear Defogger Relay, Heated Mirror
Relay
Circuit
BreakersUsage
POWER
SEATS BRKRPower Seat Circuit Breaker
REAR DEFOG
BRKRRear Defogger Breaker
5-99

At Least Twice a Year
Restraint System Check
Make sure the safety belt reminder light and all your
belts, buckles, latch plates, retractors and anchorages
are working properly. Look for any other loose or
damaged safety belt system parts. If you see anything
that might keep a safety belt system from doing its
job, have it repaired. Have any torn or frayed safety
belts replaced.
Also look for any opened or broken air bag coverings,
and have them repaired or replaced. (The air bag
system does not need regular maintenance.)
Wiper Blade Check
Inspect wiper blades for wear or cracking. Replace
blade inserts that appear worn or damaged or that
streak or miss areas of the windshield. Also see
Cleaning the Outside of Your Vehicle on page 5-88.
Weatherstrip Lubrication
Silicone grease on weatherstrips will make them last
longer, seal better, and not stick or squeak. Apply
silicone grease with a clean cloth. During very cold,
damp weather more frequent application may be
required. See
Part D: Recommended Fluids and
Lubricants on page 6-16.
Automatic Transaxle Check
Check the transaxle ¯uid level; add if needed. SeeAutomatic Transaxle Fluid on page 5-24. A ¯uid loss
may indicate a problem. Check the system and repair
if needed.
At Least Once a Year
Key Lock Cylinders Service
Lubricate the key lock cylinders with the lubricant
speci®ed in Part D.
Body Lubrication Service
Lubricate all hinges and latches, including those for the
body doors, hood, secondary latch, pivots, spring
anchor, release pawl, rear compartment, glove box door,
console door and any folding seat hardware. Part D
tells you what to use. More frequent lubrication may be
required when exposed to a corrosive environment.
6-11