light CHEVROLET C3500 HD 2002 4.G Service Manual

4-24
Winter Driving
Here are some tips for winter driving:

Have your vehicle in good shape for winter.

You may want to put winter emergency supplies in
your vehicle.Include an ice scraper, a small brush or broom, a supply
of windshield washer fluid, a rag, some winter outer
clothing, a small shovel, a flashlight, a red cloth and
reflective warning triangles. And, if you will be driving
under severe conditions, include a small bag of sand, a
piece of old carpet or a couple of burlap bags to help
provide traction. Be sure you properly secure these
items in your vehicle.
Driving on Snow or Ice
Most of the time, those places where your tires meet
the road probably have good traction.
However, if there is snow or ice between your tires
and the road, you can have a very slippery situation.
You'll have a lot less traction or ªgripº and will need
to be very careful.

4-27
CAUTION:
Snow can trap exhaust gases under your vehicle.
This can cause deadly CO (carbon monoxide) gas
to get inside. CO could overcome you and kill
you. You can't see it or smell it, so you might not
know it is in your vehicle. Clear away snow from
around the base of your vehicle, especially any
that is blocking your exhaust pipe. And check
around again from time to time to be sure snow
doesn't collect there.
Open a window just a little on the side of the
vehicle that's away from the wind. This will help
keep CO out.
Run your engine only as long as you must. This saves
fuel. When you run the engine, make it go a little faster
than just idle. That is, push the accelerator slightly.
This uses less fuel for the heat that you get and it
keeps the battery (or batteries) charged. You will need a
well
-charged battery (or batteries) to restart the vehicle,
and possibly for signaling later on with your headlamps.
Let the heater run for a while.If you have a diesel engine, you may have to run it at a
higher speed to get enough heat. Then, shut the engine
off and close the window almost all the way to preserve
the heat. Start the engine again and repeat this only
when you feel really uncomfortable from the cold.
But do it as little as possible. Preserve the fuel as long
as you can. To help keep warm, you can get out of
the vehicle and do some fairly vigorous exercises every
half hour or so until help comes.
Recreational Vehicle Towing
Recreational vehicle towing means towing your vehicle
behind another vehicle
-- such as behind a motorhome.
The two most common types of recreational vehicle
towing are known as ªdinghy towingº (towing your
vehicle with all four wheels on the ground) and ªdolly
towingº (towing your vehicle with two wheels on
the ground and two wheels up on a device known
as a ªdollyº).
Your vehicle was not designed to be towed with any of
its wheels on the ground. If your vehicle must be towed,
see ªTowing Your Vehicleº in the Index.

5-3
Jump Starting
If your battery (or batteries) have run down, you may
want to use another vehicle and some jumper cables to
start your vehicle. Be sure to follow the steps below to
do it safely.
CAUTION:
Batteries can hurt you. They can be
dangerous because:

They contain acid that can burn you.

They contain gas that can explode or ignite.

They contain enough electricity to
burn you.
If you don't follow these steps exactly, some or all
of these things can hurt you.
NOTICE:
Ignoring these steps could result in costly damage
to your vehicle that wouldn't be covered by
your warranty.
The ACDelco battery in your vehicle has a
built
-in hydrometer. Do not charge, test or jump
start the battery if the hydrometer looks clear
or light yellow. Replace the battery when there
is a clear or light yellow hydrometer and a
cranking complaint.
Trying to start your vehicle by pushing or pulling
it won't work, and it could damage your vehicle.
1. Check the other vehicle. It must have a 12-volt
battery with a negative ground system.
NOTICE:
If the other system isn't a 12-volt system with a
negative ground, both vehicles can be damaged.

5-4
If your vehicle has more than one battery, use the
battery that's closer to the starter
-- this will reduce
electrical resistance.
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.
3. To avoid the possibility of the vehicles rolling, set
the parking brake firmly on both vehicles involved in
the jump start procedure. Put an automatic
transmission in PARK (P) or a manual transmission
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.
4. Turn off the ignition on both vehicles. Unplug
unnecessary accessories plugged into the cigarette
lighter or 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!
5. Open the hoods and locate the batteries. Find the
positive (+) and negative (
-) terminal locations
on each vehicle. On vehicles equipped with dual
batteries, make any battery connections to the
primary battery located on the passenger's side of the
vehicle. See ªEngine Compartment Overviewº in the
Index for more information on location.
CAUTION:
If your vehicle has air conditioning, the auxiliary
electric fan under the hood 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.

5-5
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 flashlight if
you need more light.
Be sure the batteries have enough water. You
don't need to add water to the ACDelco
battery
(or batteries) installed in every new GM vehicle.
But if a battery has filler caps, be sure the right
amount of fluid is there. If it is low, add water to
take care of that first. If you don't, explosive gas
could be present.
Battery fluid contains acid that can burn you.
Don't get it on you. If you accidentally get it in
your eyes or on your skin, flush the place with
water and get medical help immediately.
CAUTION:
Fans or other moving engine parts can injure you
badly. Keep your hands away from moving parts
once the engine is running.
6. Check that the jumper cables don't have loose or
missing insulation. If they do, you could get a shock.
The vehicles could be damaged too.
Before you connect the cables, here are some basic
things you should know. Positive (+) will go to
positive (+) or to a remote positive (+) terminal if the
vehicle has one. Negative (
-) will go to a heavy,
unpainted metal engine part or to a negative (
-)
terminal if the vehicle has one. Don't connect
positive (+) to negative (
-) or you'll get a short that
would damage the battery and maybe other parts too.
And don't connect the negative (
-) cable to the
negative (
-) terminal on the dead battery because this
can cause sparks.

5-10 Overheated Engine Protection
Operating Mode
If an overheated engine condition exists and the
REDUCED ENGINE POWER light is displayed, an
overheat protection mode which alternates firing groups
of cylinders helps prevent engine damage. In this mode,
you will notice a loss in power and engine performance.
This operating mode allows your vehicle to be driven
to a safe place in an emergency. 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 and change the oil. See
ªEngine Oilº in the Index.
If Steam Is Coming From Your Engine

5-23
If You're Stuck: In Sand, Mud, Ice
or Snow
In order to free your vehicle when it is stuck, you will
need to spin the wheels, but you don't want to spin your
wheels too fast. The method known as ªrockingº can
help you get out when you're stuck, but you must
use caution.
CAUTION:
If you let your tires spin at high speed, they can
explode, and you or others could be injured. And,
the transmission or other parts of the vehicle can
overheat. That could cause an engine
compartment fire or other damage. When you're
stuck, spin the wheels as little as possible. Don't
spin the wheels above 35 mph (55 km/h) as shown
on the speedometer.
NOTICE:
Spinning your wheels can destroy parts of your
vehicle as well as the tires. If you spin the wheels
too fast while shifting your transmission back
and forth, you can destroy your transmission.
For information about using tire chains on your vehicle,
see ªTire Chainsº in the Index.
Rocking Your Vehicle To Get It Out
First, turn your steering wheel left and right. That will
clear the area around your front wheels. Then shift back
and forth between REVERSE (R) and a forward gear
(or with a manual transmission, between FIRST (1) or
SECOND (2) and REVERSE (R)), spinning the wheels
as little as possible. Release the accelerator pedal while
you shift, and press lightly on the accelerator pedal
when the transmission is in gear. By slowly spinning
your wheels in the forward and reverse directions, you
will cause a rocking motion that may free your vehicle.
If that doesn't get you out after a few tries, you may
need to be towed out. If you do need to be towed out,
see ªTowing Your Vehicleº in the Index.

6-6
To remove the fuel cap, turn it slowly to the
left (counterclockwise).
CAUTION:
If you get gasoline on yourself and then
something ignites it, you could be badly burned.
Gasoline can spray out on you if you open the
fuel cap too quickly. This spray can happen if
your tank is nearly full, and is more likely in hot
weather. Open the fuel cap slowly and wait for
any ªhissº noise to stop. Then unscrew the cap
all the way.
Be careful not to spill gasoline. Clean gasoline from
painted surfaces as soon as possible. See ªCleaning the
Outside of Your Vehicleº in the Index.When you put the fuel cap back on, turn it to the right
(clockwise) until you hear a clicking sound. Make sure
you fully install the cap. The diagnostic system can
determine if the fuel cap has been left off or improperly
installed. This would allow fuel to evaporate into the
atmosphere. See ªMalfunction Indicator Lampº in
the Index.
NOTICE:
If you need a new fuel cap, be sure to get the
right type. Your dealer can get one for you.
If you get the wrong type, it may not fit properly.
This may cause your malfunction indicator lamp
to light and may damage your fuel tank and
emissions system. See ªMalfunction Indicator
Lampº in the Index.

6-33 Brake Wear
Your vehicle has four-wheel disc brakes without wear
indicators. If you ever hear a brake rubbing noise,
have the brake linings inspected.
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 first 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 specifications.
Brake linings should always be replaced as complete
axle sets.
See ªBrake System Inspectionº in Section 7 of this
manual under Part C ªPeriodic Maintenance Inspections.º
Brake Pedal Travel
See your dealer if the brake pedal does not return to
normal height, or if there is a rapid increase in pedal
travel. This could be a sign of brake trouble.
Brake Adjustment
Every time you make a brake stop, your disc brakes
adjust for wear.

6-61 Fuses and Circuit Breakers
The wiring circuits in your vehicle are protected from
short circuits by a combination of fuses, circuit breakers
and fusible thermal links. This greatly reduces the
chance of fires caused by electrical problems.
Look at the silver
-colored band inside the fuse. If the
band is broken or melted, replace the fuse. Be sure you
replace a bad fuse with a new one of the identical size
and rating.
If you ever have a problem on the road and don't have
a spare fuse, you can borrow one that has the same
amperage. Just pick some feature of your vehicle that
you can get along without
-- like the radio or cigarette
lighter
-- and use its fuse, if it is the correct amperage.
Replace it as soon as you can.Instrument Panel Fuse Block
The fuse block access door
is on the driver's side edge
of the instrument panel.
Pull off the cover to access
the fuse block.
You can remove fuses with a fuse extractor which is
mounted to the fuse block access door. To remove fuses
if you don't have a fuse extractor, hold the end of the
fuse between your thumb and index finger and pull
straight out.
You may have spare fuses located behind the fuse block
access door. These can be used to replace a bad fuse.
However, make sure it is of the correct amperage.