engine CHEVROLET VENTURE 2004 1.G Service Manual

Traction Control System (TCS)
Your vehicle may have a traction control system that
limits wheel spin. This is especially useful in slippery
road conditions. The system operates only if it senses
that one or both of the front wheels are spinning or
beginning to lose traction. When this happens,
the system works the front brakes and reduces engine
power to limit wheel spin.
The TRACTION ACTIVE message will come on when
the traction control system is limiting wheel spin.
SeeTraction Active Message on page 3-42. You may
feel or hear the system working, but this is normal.
If your vehicle is in cruise control when the traction
control system begins to limit wheel spin, the cruise
control will automatically disengage. When road
conditions allow you to safely use it again, you may
reengage the cruise control. See “Cruise Control” under
Turn Signal/Multifunction Lever on page 3-6.If this message comes on and stays on or comes on
while you are driving, there’s a problem with your
traction control system.
SeeService Traction System Warning Message on
page 3-41. When this warning message is on, the
TRAC OFF light will come on to remind you that the
system will not limit wheel spin. Adjust your driving
accordingly.
The traction control system automatically comes on
whenever you start your vehicle. To limit wheel spin,
especially in slippery road conditions, you should always
leave the system on. But you can turn the traction control
system off if you ever need to. You should turn the
system off if your vehicle ever gets stuck in sand, mud or
snow and rocking the vehicle is required. See “Rocking
Your Vehicle” underIf You Are Stuck: In Sand, Mud, Ice
or Snow on page 4-32. United States
Canada
4-10

To turn the system off,
press the TCS button
located on the instrument
panel switchbank.
If the system is limiting wheel spin when you press the
button, the traction active message will go off, but
the system will not turn off until there is no longer a
current need to limit wheel spin. The TRAC OFF light will
come on to remind you the system is off. You can
turn the system back on at any time by pressing the
button again. The traction control system warning
message should go off.All-Wheel Drive (AWD) System
If your vehicle has all-wheel drive (AWD), the AWD
system operates automatically without any action
required by the driver. If the front drive wheels begin to
slip, the rear wheels will automatically begin to drive
the vehicle as required. There may be a slight
engagement noise during hard use but this is normal.
During heavy AWD applications, the engine torque may
be reduced to protect AWD system components. If the
vehicle is exposed to extended heavy AWD usage, the
AWD system will shut itself off to protect the system from
overheating. When the system cools down, the AWD
system will activate itself again automatically; this
cool-down can take up to 20 minutes depending on
outside temperature and vehicle use. SeeAll-Wheel
Drive Disable Warning Message on page 3-46.
4-11

Steering
Power Steering
If you lose power steering assist because the engine
stops or the system is not functioning, you can steer but
it will take much more effort.
Steering Tips
Driving on Curves
It is important to take curves at a reasonable speed.
A lot of the “driver lost control” accidents mentioned on
the news happen on curves. Here is why:
Experienced driver or beginner, each of us is subject to
the same laws of physics when driving on curves.
The traction of the tires against the road surface makes
it possible for the vehicle to change its path when
you turn the front wheels. If there is no traction, inertia
will keep the vehicle going in the same direction. If
you have ever tried to steer a vehicle on wet ice, you
will understand this.
The traction you can get in a curve depends on the
condition of your tires and the road surface, the angle at
which the curve is banked, and your speed. While you are
in a curve, speed is the one factor you can control.Suppose you are steering through a sharp curve.
Then you suddenly apply the brakes. Both control
systems — steering and braking — have to do their work
where the tires meet the road. Unless you have
four-wheel anti-lock brakes, adding the hard braking can
demand too much of those places. You can lose control.
The same thing can happen if you are steering through
a sharp curve and you suddenly accelerate. Those
two control systems — steering and acceleration — can
overwhelm those places where the tires meet the
road and make you lose control. SeeTraction Control
System (TCS) on page 4-10.
What should you do if this ever happens? Ease up on
the brake or accelerator pedal, steer the vehicle the way
you want it to go, and slow down.
Speed limit signs near curves warn that you should
adjust your speed. Of course, the posted speeds
are based on good weather and road conditions. Under
less favorable conditions you will want to go slower.
If you need to reduce your speed as you approach
a curve, do it before you enter the curve, while your front
wheels are straight ahead.
Try to adjust your speed so you can “drive” through the
curve. Maintain a reasonable, steady speed. Wait to
accelerate until you are out of the curve, and then
accelerate gently into the straightaway.
4-12

While driving on a surface with reduced traction, try
your best to avoid sudden steering, acceleration
or braking (including engine braking by shifting to a
lower gear). Any sudden changes could cause the tires
to slide. You may not realize the surface is slippery
until your vehicle is skidding. Learn to recognize warning
clues — such as enough water, ice or packed snow
on the road to make a “mirrored surface” — and slow
down when you have any doubt.
If you have the anti-lock braking system, remember: It
helps avoid only the braking skid. If you do not have
anti-lock, then in a braking skid (where the wheels are
no longer rolling), release enough pressure on the
brakes to get the wheels rolling again. This restores
steering control. Push the brake pedal down steadily
when you have to stop suddenly. As long as the wheels
are rolling, you will have steering control.Driving at Night
Night driving is more dangerous than day driving. One
reason is that some drivers are likely to be impaired — by
alcohol or drugs, with night vision problems, or by fatigue.
4-17

Hydroplaning
Hydroplaning is dangerous. So much water can build up
under your tires that they can actually ride on the
water. This can happen if the road is wet enough and
you are going fast enough. When your vehicle is
hydroplaning, it has little or no contact with the road.
Hydroplaning does not happen often. But it can if your
tires do not have much tread or if the pressure in
one or more is low. It can happen if a lot of water is
standing on the road. If you can see reections
from trees, telephone poles or other vehicles, and
raindrops “dimple” the water’s surface, there could be
hydroplaning.
Hydroplaning usually happens at higher speeds. There
just is not a hard and fast rule about hydroplaning.
The best advice is to slow down when it is raining.
Driving Through Deep Standing Water
Notice:If you drive too quickly through deep
puddles or standing water, water can come in
through your engine’s air intake and badly damage
your engine. Never drive through water that is
slightly lower than the underbody of your vehicle. If
you can not avoid deep puddles or standing
water, drive through them very slowly.
Driving Through Flowing Water
{CAUTION:
Flowing or rushing water creates strong forces.
If you try to drive through owing water, as you
might at a low water crossing, your vehicle can
be carried away. As little as six inches of
owing water can carry away a smaller vehicle.
If this happens, you and other vehicle
occupants could drown. Do not ignore police
warning signs, and otherwise be very cautious
about trying to drive through owing water.
4-21

Before Leaving on a Long Trip
Make sure you are ready. Try to be well rested. If you
must start when you are not fresh — such as after
a day’s work — do not plan to make too many miles that
rst part of the journey. Wear comfortable clothing
and shoes you can easily drive in.
Is your vehicle ready for a long trip? If you keep it
serviced and maintained, it is ready to go. If it needs
service, have it done before starting out. Of course, you
will nd experienced and able service experts in GM
dealerships all across North America. They will be ready
and willing to help if you need it.Here are some things you can check before a trip:Windshield Washer Fluid:Is the reservoir full?
Are all windows clean inside and outside?
Wiper Blades:Are they in good shape?
Fuel, Engine Oil, Other Fluids:Have you checked
all levels?
Lamps:Are they all working? Are the lenses clean?
Tires:They are vitally important to a safe,
trouble-free trip. Is the tread good enough for
long-distance driving? Are the tires all inated to the
recommended pressure?
Weather Forecasts:What is the weather outlook
along your route? Should you delay your trip a
short time to avoid a major storm system?
Maps:Do you have up-to-date maps?
4-25

Highway Hypnosis
Is there actually such a condition as “highway hypnosis”?
Or is it just plain falling asleep at the wheel? Call it
highway hypnosis, lack of awareness, or whatever.
There is something about an easy stretch of road with the
same scenery, along with the hum of the tires on the
road, the drone of the engine, and the rush of the wind
against the vehicle that can make you sleepy. Do not let it
happen to you! If it does, your vehicle can leave the road
inless than a second,and you could crash and be
injured.
What can you do about highway hypnosis? First, be
aware that it can happen.
Then here are some tips:
Make sure your vehicle is well ventilated, with a
comfortably cool interior.
Keep your eyes moving. Scan the road ahead and
to the sides. Check your mirrors and your
instruments frequently.
If you get sleepy, pull off the road into a rest,
service or parking area and take a nap, get some
exercise, or both. For safety, treat drowsiness
on the highway as an emergency.
Hill and Mountain Roads
Driving on steep hills or mountains is different from
driving in at or rolling terrain.
4-26

If you drive regularly in steep country, or if you are
planning to visit there, here are some tips that can make
your trips safer and more enjoyable.
Keep your vehicle in good shape. Check all uid
levels and also the brakes, tires, cooling system
and transaxle. These parts can work hard on
mountain roads.
Know how to go down hills. The most important
thing to know is this: let your engine do some of
the slowing down. Shift to a lower gear when you go
down a steep or long hill.
{CAUTION:
If you do not shift down, your brakes could get
so hot that they would not work well. You
would then have poor braking or even none
going down a hill. You could crash. Shift down
to let your engine assist your brakes on a
steep downhill slope.
{CAUTION:
Coasting downhill in NEUTRAL (N) or with the
ignition off is dangerous. Your brakes will have
to do all the work of slowing down. They could
get so hot that they would not work well. You
would then have poor braking or even none
going down a hill. You could crash. Always have
your engine running and your vehicle in gear
when you go downhill.
Know how to go uphill. You may want to shift down to
a lower gear. The lower gears help cool your engine
and transaxle, and you can climb the hill better.
Stay in your own lane when driving on two-lane
roads in hills or mountains. Do not swing wide or cut
across the center of the road. Drive at speeds that let
you stay in your own lane.
As you go over the top of a hill, be alert. There could
be something in your lane, like a stalled car or an
accident.
You may see highway signs on mountains that warn
of special problems. Examples are long grades,
passing or no-passing zones, a falling rocks area or
winding roads. Be alert to these and take appropriate
action.
4-27

Put on extra clothing or wrap a blanket around you. If
you have no blankets or extra clothing, make body
insulators from newspapers, burlap bags, rags, oor
mats — anything you can wrap around yourself or
tuck under your clothing to keep warm.
You can run the engine to keep warm, but be careful.
{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 not 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 does
not collect there.
Open a window just a little on the side of the
vehicle that is away from the wind. This will
help keep CO out.
4-31

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 charged. You will need a
well-charged battery to restart the vehicle, and possibly
for signaling later on with your headlamps. Let the
heater run for a while.
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.
If You Are 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 do not want to spin your
wheels too fast. The method known as “rocking” can help
you get out when you are 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 transaxle or other parts of the vehicle
can overheat. That could cause an engine
compartment re or other damage. When you
are stuck, spin the wheels as little as possible.
Do not 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 transaxle back
and forth, you can destroy your transaxle. See
“Rocking Your Vehicle To Get It Out.”
For information about using tire chains on your vehicle,
seeTire Chains on page 5-68.
4-32