light GMC SAVANA PASSENGER 2009 Repair Manual

Braking
SeeBrake System Warning Light on page 3-31.
Braking action involves perception time and reaction
time. Deciding to push the brake pedal is perception
time. Actually doing it is reaction time.
Average reaction time is about three-fourths of
a second. But that is only an average. It might
be less with one driver and as long as two or
three seconds or more with another. Age, physical
condition, alertness, coordination, and eyesight all
play a part. So do alcohol, drugs, and frustration.
But even in three-fourths of a second, a vehicle
moving at 60 mph (100 km/h) travels 66 feet (20 m).
That could be a lot of distance in an emergency,
so keeping enough space between the vehicle and
others is important.
And, of course, actual stopping distances vary greatly
with the surface of the road, whether it is pavement
or gravel; the condition of the road, whether it is
wet, dry, or icy; tire tread; the condition of the brakes;
the weight of the vehicle; and the amount of brake force
applied.Avoid needless heavy braking. Some people drive in
spurts — heavy acceleration followed by heavy
braking — rather than keeping pace with traffic. This is a
mistake. The brakes might not have time to cool between
hard stops. The brakes will wear out much faster with a
lot of heavy braking. Keeping pace with the traffic and
allowing realistic following distances eliminates a lot of
unnecessary braking. That means better braking and
longer brake life.
If the engine ever stops while the vehicle is being driven,
brake normally but do not pump the brakes. If the brakes
are pumped, the pedal could get harder to push down.
If the engine stops, there will still be some power brake
assist but it will be used when the brake is applied. Once
the power assist is used up, it can take longer to stop and
the brake pedal will be harder to push.
Adding non-dealer/non-retailer accessories can affect
vehicle performance. SeeAccessories and Modifications
on page 5-3.
4-4

Antilock Brake System (ABS)
This vehicle has the Antilock Brake System (ABS), an
advanced electronic braking system that helps prevent a
braking skid.
When the engine is started and the vehicle begins to
drive away, ABS checks itself. A momentary motor
or clicking noise might be heard while this test is going
on. This is normal.
If there is a problem with
the ABS, this warning light
stays on. SeeAntilock
Brake System (ABS)
Warning Light on
page 3-32.
Let us say the road is wet and you are driving safely.
Suddenly, an animal jumps out in front of you. You slam
on the brakes and continue braking. Here is what
happens with ABS:
A computer senses that the wheels are slowing down.
If one of the wheels is about to stop rolling, the computer
will separately work the brakes at each front wheel
and at both rear wheels.ABS can change the brake pressure to each wheel, as
required, faster than any driver could. This can help
the driver steer around the obstacle while braking hard.
As the brakes are applied, the computer keeps
receiving updates on wheel speed and controls braking
pressure accordingly.
Remember: ABS does not change the time needed to get
a foot up to the brake pedal or always decrease stopping
distance. If you get too close to the vehicle in front of you,
there will not be enough time to apply the brakes if that
vehicle suddenly slows or stops. Always leave enough
room up ahead to stop, even with ABS.
Using ABS
Do not pump the brakes. Just hold the brake pedal
down firmly and let antilock work. The brakes might
vibrate or some noise might be heard, but this is normal.
Braking in Emergencies
ABS allows the driver to steer and brake at the same
time. In many emergencies, steering can help more than
even the very best braking.
4-5

StabiliTrak®System
The vehicle may have a vehicle stability enhancement
system called StabiliTrak. It is an advanced computer
controlled system that assists the driver with directional
control of the vehicle in difficult driving conditions.
StabiliTrak activates when the computer senses a
discrepancy between the intended path and the direction
the vehicle is actually traveling. StabiliTrak selectively
applies braking pressure at any one of the vehicle’s
brakes to assist the driver with keeping the vehicle on
the intended path.
When the vehicle is started and begins to move, the
system performs several diagnostic checks to insure
there are no problems. The system may be heard or felt
while it is working. This is normal and does not mean
there is a problem with the vehicle. The system
should initialize before the vehicle reaches 20 mph
(32 km/h). In some cases, it may take approximately
2 miles (3.2 km) of driving before the system initializes.Press and hold the
StabiliTrak button located
on the instrument panel
for more than five seconds
to turn off StabiliTrak
and part of the traction
control system.
The StabiliTrak light comes
on the instrument panel
cluster when the system is
turned off or requires
service.
For more information, seeStabiliTrak
®Indicator Light
on page 3-33.
For your safety, the system can only be disabled when
the vehicle speed is less than 20 mph (32 km/h). Three
chimes will be heard and the StabiliTrak light comes on.
4-6

To turn on the StabiliTrak system, press the StabiliTrak
button again. StabiliTrak will automatically turn back on
when the vehicle speed exceeds 20 mph (32 km/h).
One chime is heard and the StabiliTrak light will turn off.
When the StabiliTrak system has been turned off,
system noises may still be heard as a result of the
brake-traction control coming on.
It is recommended to leave the system on for normal
driving conditions, but it may be necessary to turn
the system off if the vehicle is stuck in sand, mud, ice or
snow, and you want to “rock” the vehicle to attempt to
free it. SeeIf Your Vehicle is Stuck in Sand, Mud, Ice, or
Snow on page 4-17.
StabiliTrak System Operation
The StabiliTrak system is normally on, except when the
system is initializing or has been disabled with the
StabiliTrak button. The StabiliTrak system will
automatically activate to assist the driver in maintaining
vehicle directional control in most driving conditions.
When activated, the StabiliTrak system may reduce
engine power to the wheels and apply braking to
individual wheels as necessary to assist the driver with
vehicle directional control. If cruise control is being
used when StabiliTrak activates, the cruise control
automatically disengages. The cruise control can be
re-engaged when road conditions allow. SeeCruise
Control on page 3-9.The StabiliTrak system may also turn off automatically if
it determines that a problem exists with the system.
If the problem does not clear itself after restarting the
vehicle, see your dealer/retailer for service.
Traction Control Operation
The traction control system is part of the StabiliTrak
system. Traction control limits wheel spin by reducing
engine power to the wheels and by applying brakes to
each individual wheel as necessary.
If the brake-traction control system activates constantly
or if the brakes have heated up due to high speed
braking, the brake-traction control will be automatically
disabled. The system will come back on after the brakes
have cooled. This can take up to two minutes or longer
depending on brake usage.
The traction control system may activate on dry or rough
roads or under conditions such as heavy acceleration
while turning or abrupt upshifts/downshifts of the
transmission. When this a reduction in acceleration
may be noticed, or a noise or vibration may be heard.
This is normal.
Adding non-dealer/non-retailer accessories can affect
the vehicle’s performance. SeeAccessories and
Modifications on page 5-3for more information.
4-7

Off-Road Recovery
The vehicle’s right wheels can drop off the edge of a
road onto the shoulder while driving.
If the level of the shoulder is only slightly below the
pavement, recovery should be fairly easy. Ease off the
accelerator and then, if there is nothing in the way,
steer so that the vehicle straddles the edge of the
pavement. Turn the steering wheel 3 to 5 inches,
8 to 13 cm, (about one-eighth turn) until the right front
tire contacts the pavement edge. Then turn the steering
wheel to go straight down the roadway.
Passing
Passing another vehicle on a two-lane road can be
dangerous. To reduce the risk of danger while passing:
•Look down the road, to the sides, and to crossroads
for situations that might affect a successful pass.
If in doubt, wait.
•Watch for traffic signs, pavement markings, and
lines that could indicate a turn or an intersection.
Never cross a solid or double-solid line on your side
of the lane.
•Do not get too close to the vehicle you want to
pass. Doing so can reduce your visibility.
•Wait your turn to pass a slow vehicle.
•When you are being passed, ease to the right.
4-10

Driving at Night
Night driving is more dangerous than day driving
because some drivers are likely to be impaired — by
alcohol or drugs, with night vision problems, or by fatigue.
Night driving tips include:
•Drive defensively.
•Do not drink and drive.
•Reduce headlamp glare by adjusting the inside
rearview mirror.
•Slow down and keep more space between you and
other vehicles because headlamps can only light up
so much road ahead.
•Watch for animals.
•When tired, pull off the road.
•Do not wear sunglasses.
•Avoid staring directly into approaching headlamps.
•Keep the windshield and all glass on your vehicle
clean — inside and out.
•Keep your eyes moving, especially during turns or
curves.
No one can see as well at night as in the daytime. But, as
we get older, these differences increase. A 50-year-old
driver might need at least twice as much light to see the
same thing at night as a 20-year-old.
Driving in Rain and on Wet Roads
Rain and wet roads can reduce vehicle traction
and affect your ability to stop and accelerate. Always
drive slower in these types of driving conditions
and avoid driving through large puddles and
deep-standing or flowing water.
{CAUTION:
Wet brakes can cause crashes. They might not
work as well in a quick stop and could cause
pulling to one side. You could lose control of the
vehicle.
After driving through a large puddle of water or a
car/vehicle wash, lightly apply the brake pedal until
the brakes work normally.
Flowing or rushing water creates strong forces.
Driving through flowing water could cause your
vehicle to be carried away. If this happens, you
and other vehicle occupants could drown. Do not
ignore police warnings and be very cautious about
trying to drive through flowing water.
4-12

To save fuel, run the engine for only short periods as
needed to warm the vehicle and then shut the engine off
and close the window most of the way to save heat.
Repeat this until help arrives but only when you
feel really uncomfortable from the cold. Moving about to
keep warm also helps.
If it takes some time for help to arrive, now and then
when you run the engine, push the accelerator
pedal slightly so the engine runs faster than the idle
speed. This keeps the battery charged to restart
the vehicle and to signal for help with the headlamps.
Do this as little as possible to save fuel.
If Your Vehicle is Stuck in Sand,
Mud, Ice, or Snow
Slowly and cautiously spin the wheels to free the
vehicle when stuck in sand, mud, ice, or snow. See
Rocking Your Vehicle to Get It Out on page 4-18.
If the vehicle has a traction system, it can often help
to free a stuck vehicle. Refer to the vehicle’s traction
system in the Index. If stuck too severely for the traction
system to free the vehicle, turn the traction system off
and use the rocking method.
{CAUTION:
If you let your vehicle’s tires spin at high speed,
they can explode, and you or others could be
injured. The vehicle can overheat, causing an
engine compartment fire or other damage. Spin
the wheels as little as possible and avoid going
above 35 mph (55 km/h) as shown on the
speedometer.
For information about using tire chains on the vehicle,
seeTire Chains on page 5-78.
4-17

Rocking Your Vehicle to Get It Out
Turn the steering wheel left and right to clear the
area around the front wheels. Turn off any traction
or stability system. Shift back and forth between
R (Reverse) and a forward gear, spinning the wheels as
little as possible. To prevent transmission wear, wait
until the wheels stop spinning before shifting gears.
Release the accelerator pedal while shifting, and press
lightly on the accelerator pedal when the transmission
is in gear. Slowly spinning the wheels in the forward and
reverse directions causes a rocking motion that could
free the vehicle. If that does not get the vehicle out
after a few tries, it might need to be towed out. If the
vehicle does need to be towed out, seeTowing
Your Vehicle on page 4-24.
Loading the Vehicle
It is very important to know how much weight your
vehicle can carry. This weight is called the vehicle
capacity weight and includes the weight of all
occupants, cargo, and all nonfactory-installed
options. Two labels on your vehicle show how
much weight it was designed to carry, the Tire
and Loading Information label and the Certification/
Tire label.
{CAUTION:
Do not load the vehicle any heavier than the
Gross Vehicle Weight Rating (GVWR), or
either the maximum front or rear Gross Axle
Weight Rating (GAWR). If you do, parts on the
vehicle can break, and it can change the way
your vehicle handles. These could cause you
to lose control and crash. Also, overloading
can shorten the life of the vehicle.
4-18

•Then, during the first 500 miles (800 km) that a
trailer is towed, do not drive over 50 mph (80 km/h)
and do not make starts at full throttle. This helps
the engine and other parts of the vehicle wear in at
the heavier loads.
•Vehicles with an automatic transmissions can tow in
D (Drive). Shift the transmission to a lower gear if
the transmission shifts too often under heavy
loads and/or hilly conditions.
Three important considerations have to do with weight:
•The weight of the trailer
•The weight of the trailer tongue
•The weight on the vehicle’s tires
Also see Tow/Haul later in this section for information
about the Tow/Haul button and the Tow/Haul indicator
light.
Weight of the Trailer
How heavy can a trailer safely be?
It depends on how the rig is used. For example, speed,
altitude, road grades, outside temperature and how
much the vehicle is used to pull a trailer are all
important. It can depend on any special equipment on
the vehicle, and the amount of tongue weight the vehicle
can carry. See “Weight of the Trailer Tongue” later in
this section for more information.
Maximum trailer weight is calculated assuming only the
driver is in the tow vehicle and it has all the required
trailering equipment. The weight of additional optional
equipment, passengers and cargo in the tow vehicle
must be subtracted from the maximum trailer weight.
4-29

If the loaded trailer being pulled will weigh more than
5,000 lbs (2 270 kg), be sure to use a properly mounted
weight-distributing hitch and sway control of the proper
size. This equipment is very important for proper vehicle
loading and good handling when driving. Always use a
sway control if the trailer will weigh more than these
limits. Ask a hitch dealer about sway controls.
Will any holes need to be made in the body of the
vehicle when a trailer hitch is installed?
If using the wiring provided with the factory-installed
trailering package, no holes need to be made in
the body of the vehicle. However, if an aftermarket hitch
is installed, holes may need to be made in the body.
If holes are made in the body, then be sure to seal the
holes later when the hitch is removed. If the holes
are not sealed, deadly carbon monoxide (CO) from the
engine’s exhaust can get into the vehicle as well as
dirt and water. See “Carbon Monoxide” underEngine
Exhaust on page 2-30.
Safety Chains
Always attach chains between the vehicle and the
trailer. Cross the safety chains under the tongue of the
trailer to help prevent the tongue from contacting
the road if it becomes separated from the hitch. Always
leave just enough slack so the rig can turn. Never
allow safety chains to drag on the ground.
Tow/Haul Mode
Pressing this button at
the end of the shift lever
turns on and off the
tow/haul mode.
This indicator light on the
instrument panel cluster
comes on when the
tow/haul mode is on.
Tow/Haul is a feature that assists when pulling a heavy
trailer or a large or heavy load. SeeTow/Haul Mode
on page 2-25for more information.
4-35