If you decide you can go down a hill safely, try to keep
the vehicle headed straight down. Use a low gear
so engine drag can help the brakes so they do not
have to do all the work. Descend slowly, keeping the
vehicle under control at all times.
{CAUTION:
Heavy braking when going down a hill can cause
your brakes to overheat and fade. This could cause
loss of control and a serious accident. Apply the
brakes lightly when descending a hill and use a low
gear to keep vehicle speed under control.Things not to do when driving down a hill:
When driving downhill, avoid turns that take you
across the incline of the hill. A hill that is not too
steep to drive down might be too steep to drive
across. The vehicle could roll over.
Never go downhill with the transmission in
N (Neutral), called free-wheeling. The brakes will
have to do all the work and could overheat and fade.
Vehicles are much more likely to stall when going uphill,
but if it happens when going downhill:
1. Stop the vehicle by applying the regular brakes and
apply the parking brake.
2. Shift to P (Park) and, while still braking, restart the
engine.
3. Shift back to a low gear, release the parking brake,
and drive straight down.
4. If the engine will not start, get out and get help.
4-23
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 owing 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 owing 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 owing water.
4-27
CAUTION: (Continued)
Open a window about two inches (5 cm) on
the side of the vehicle that is away from the
wind to bring in fresh air.
Fully open the air outlets on or under the
instrument panel.
Adjust the Climate Control system to a setting
that circulates the air inside the vehicle and
set the fan speed to the highest setting.
See Climate Control System in the Index.
For more information about carbon monoxide, see
Engine Exhaust on page 2-38.
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 cannot 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 the exhaust.Run the engine for short periods only as needed to
keep warm, but be careful.
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.
4-31
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 4-32.
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 re 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 5-81.
Rocking Your Vehicle to Get It Out
Turn the steering wheel left and right to clear the area
around the front wheels. For four-wheel-drive vehicles,
shift into Four-Wheel High. For vehicles with StabiliTrak
®,
turn the traction control part of the system off. 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.
Recovery hooks can be used, if the vehicle has them.
If the vehicle does need to be towed out, seeTowing
Your Vehicle on page 4-40.
Recovery Hooks
{CAUTION:
These hooks, when used, are under a lot of force.
Always pull the vehicle straight out. Never pull on
the hooks at a sideways angle. The hooks could
break off and you or others could be injured from
the chain or cable snapping back.
4-32
Electronically Controlled Air
Suspension System
With this feature, an electronically controlled air
suspension system automatically keeps the vehicle level
as it is loaded and unloaded. The system includes a
compressor, two height sensors and two air springs
supporting the rear axle.
The system also has an internal clock to prevent
overheating if the in ator is used for prolonged periods.
If the system overheats, all leveling function stops
until the system cools down.
The ignition has to be on for the system to in ate, in order
to raise the vehicle to the standard ride height after
loading. The system can lower the vehicle to the standard
ride height after unloading with the ignition on and also for
up to 30 minutes after the ignition has been turned off.
The compressor may be heard while it is operating when
the vehicle is being loaded, and periodically as the
system adjusts the vehicle to the standard ride height.
Load leveling will not function normally with the in ator
hose attached to the in ator outlet. Remove the in ator
hose from the outlet during loading and unloading.
If the vehicle is parked for an extended period of time,
some bleed down of the suspension is normal. Upon
starting the vehicle, proper height will be achieved.
Overload Protection
The air suspension system is equipped with overload
protection. Overload protection is designed to protect
the air suspension system, and it is an indicator to the
driver that the vehicle is overloaded. When the overload
protection mode is on, it will not allow damage to the
air compressor. However, do not overload the vehicle.
SeeLoading the Vehicle on page 4-33.
If the suspension remains at a low height, the rear axle
load has exceeded GAWR (Gross Axle Weight Rating).
When the overload protection mode is activated, the
compressor operates for about 30 seconds to one minute
without raising the vehicle depending on the amount
of overload. This will continue each time the ignition
is turned on until the rear axle load is reduced
below GAWR.
Indicator Light
The indicator light on the in ator switch in the rear
passenger compartment also serves as an indicator for
internal system error. If the indicator light is ashing
without the load leveling function or the in ator being
active, turn off the ignition. The next day turn on the
ignition and check the indicator light. The vehicle can be
driven with the light ashing, but if it is, the vehicle should
be serviced as soon as possible.
4-47
The seven-wire harness contains the following trailer
circuits:
Yellow: Left Stop/Turn Signal
Dark Green: Right Stop/Turn Signal
Brown: Running Lamps
White: Ground
Light Green: Back-up Lamps
Dark Blue: Electric Brakes
Red: Battery Feed (The chassis wiring ring terminal
must be fastened to a stud on the underhood
electrical center before the trailer feed will become
active.)
If towing a light-duty trailer with a standard four-way
round pin connector, an adapter connector is available
from your dealer/retailer.
If charging a remote (non-vehicle) battery, turn on the
headlamps to boost the vehicle system voltage and
properly charge the battery.
The vehicle is also equipped with wiring for an electric
trailer brake controller. These wires are located inside the
vehicle on the driver side under the instrument panel.
These wires should be connected to an electric trailer
brake controller by your dealer/retailer or a quali ed
service center.The vehicle may be equipped with a four-pin trailer
towing harness. This harness has a four-pin trailer
connector that contains the following trailer circuits:
Yellow: Left Stop/Turn Signal
Dark Green: Right Stop/Turn Signal
Brown: Running Lamps
White: Ground
This harness also contains the following trailer circuits
that are not connected to the four-pin trailer connector:
Light Green: Back-Up Lamps
Dark Blue: Electric Brakes
Red: Battery Feed
If the vehicle is a TrailBlazer SS, a trailer wiring harness
extension, and instructions for installing this extension,
were provided when the vehicle was delivered. This
extension will allow the vehicle’s trailer wiring harness to
be more easily accessible. There is a four-way connector
on the harness. A seven-way adapter plug is also
included if the trailer requires it.
4-59
Gasoline Octane
If the vehicle has the 4.2L L6 engine (VIN Code S) or
the 5.3L V8 engine (VIN Code M), use regular unleaded
gasoline with a posted octane rating of 87 or higher. If the
octane rating is less than 87, you might notice an audible
knocking noise when you drive, commonly referred to
as spark knock. If this occurs, use a gasoline rated at
87 octane or higher as soon as possible. If you are using
gasoline rated at 87 octane or higher and you hear heavy
knocking, the engine needs service.
If the vehicle has the 6.0L V8 engine (VIN Code H),
use premium unleaded gasoline with a posted octane
rating of 91 or higher. You can also use regular unleaded
gasoline rated at 87 octane or higher, but the vehicle’s
acceleration could be slightly reduced, and you might
notice a slight audible knocking noise, commonly referred
to as spark knock. If the octane is less than 87, you might
notice a heavy knocking noise when you drive. If this
occurs, use a gasoline rated at 87 octane or higher as
soon as possible. Otherwise, you could damage the
engine. If you are using gasoline rated at 87 octane or
higher and you hear heavy knocking, the engine needs
service.
Gasoline Speci cations
At a minimum, gasoline should meet ASTM speci cation
D 4814 in the United States or CAN/CGSB-3.5 or 3.511 in
Canada. Some gasolines contain an octane-enhancing
additive called methylcyclopentadienyl manganese
tricarbonyl (MMT). We recommend against the use of
gasolines containing MMT. SeeAdditives on page 5-7
for additional information.
California Fuel
If the vehicle is certi ed to meet California Emissions
Standards, it is designed to operate on fuels that meet
California speci cations. See the underhood emission
control label. If this fuel is not available in states adopting
California emissions standards, the vehicle will operate
satisfactorily on fuels meeting federal speci cations, but
emission control system performance might be affected.
The malfunction indicator lamp could turn on and the
vehicle might fail a smog-check test. SeeMalfunction
Indicator Lamp on page 3-39. If this occurs, return to your
authorized dealer/retailer for diagnosis. If it is determined
that the condition is caused by the type of fuel used,
repairs might not be covered by the vehicle warranty.
5-6
{CAUTION:
Fuel can spray out on you if you open the fuel cap
too quickly. If you spill fuel and then something
ignites it, you could be badly burned. This spray
can happen if the tank is nearly full, and is more
likely in hot weather. Open the fuel cap slowly and
wait for any hiss noise to stop. Then unscrew the
cap all the way.
Be careful not to spill fuel. Do not top off or over ll the
tank and wait a few seconds after you have nished
pumping before removing the nozzle. Clean fuel from
painted surfaces as soon as possible. SeeWashing
Your Vehicle on page 5-113.
When replacing the fuel cap, turn it clockwise until it
clicks. Make sure the cap is fully installed. 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. SeeMalfunction Indicator Lamp on
page 3-39.There may also be a light that comes on in the
instrument panel to let you know if the gas cap is
not properly installed. SeeCheck Gas Cap Light
on page 3-47for more information.
{CAUTION:
If a re starts while you are refueling, do not
remove the nozzle. Shut off the ow of fuel by
shutting off the pump or by notifying the station
attendant. Leave the area immediately.
Notice:If you need a new fuel cap, be sure to get
the right type. Your dealer/retailer can get one
for you. If you get the wrong type, it may not t
properly. This may cause the malfunction indicator
lamp to light and may damage the fuel tank and
emissions system. SeeMalfunction Indicator Lamp
on page 3-39.
5-9