check engine HUMMER H3 2010 User Guide

Instruments and Controls 5-23
Engine Cooling System
Messages
AC (Air Conditioning) OFF
This message displays when the
engine coolant temperature is too
high and the air conditioning in
the vehicle needs to be turned off.
SeeEngine Overheating
on
page 10‑22and Climate Control
Systemson page 8‑1for more
information. This message displays
along with the ENG HOT message.
ENG (Engine) HOT
This message displays when the
engine coolant temperature is
hot. Check the engine coolant
temperature gauge. See Engine
Coolant Temperature Gauge
on
page 5‑9. Have the vehicle
serviced by your dealer as soon
as possible if you suspect the
engine is overheating. See Engine
Overheating
on page 10‑22for more
information.
Engine Oil Messages
CHANGE OIL
This message displays when the
oil needs to be changed. Check
the oil in the vehicle as soon as
possible and have the vehicle
serviced by your dealer. See Engine
Oil
on page 10‑9and Scheduled
Maintenanceon page 11‑2for
more information. Press and release
the reset stem to acknowledge the
message and clear it from the
display.
OIL
This message displays when the oil
pressure is low. See Engine Oil
Pressure Light
on page 5‑17and
Engine Oilon page 10‑9for more
information.
Engine Power Messages
REDUCED POWER
This message displays when the
vehicle's engine power is reduced.
Reduced engine power can affect
the vehicle's ability to accelerate.
If this message is on, but there
is no reduction in performance,
proceed to your destination.
The performance may be reduced
the next time the vehicle is driven.
The vehicle may be driven at a
reduced speed while this message
is on, but acceleration and speed
may be reduced. Anytime this
message stays on, the vehicle
should be taken to your dealer
for service as soon as possible.
Press and release the reset stem
to acknowledge the message and
clear it from the display.

5-24 Instruments and Controls
Fuel System Messages
FUEL CAP
This message displays if the
vehicle's fuel cap is either off or
loose. Pull over as soon as possible
and check to see if the fuel cap is
secure. You may also see the check
engine light on the instrument panel
cluster. If the check engine light
does come on when the fuel cap
was loose, it may take a few driving
trips before the light turns off.
SeeMalfunction Indicator Lamp
on
page 5‑12for more information if
the light still remains on. Press
and release the reset stem to
acknowledge the message and
clear it from the display.
LOW FUEL
This message displays if the level of
fuel in the vehicle is low. Also check
the fuel gauge. See Fuel Gauge
on
page 5‑8for more information.
Refill the fuel tank as soon as
possible.
Lamp Messages
TURN SIGNAL
This message displays when the
turn signal is on for about 1.2 km
(0.75 miles) of travel. Press
and release the reset stem to
acknowledge the message and
clear it from the display.
Ride Control System
Messages
SERVICE STAB (Stability)
SYS (System)
This message displays if there is
a problem with the StabiliTrak®
system. Have the vehicle serviced
by your dealer. See StabiliTrak
System
on page 9‑53for more
information.
STAB (Stability)
SYS (System) OFF
This message displays when the
StabiliTrak®system is turned off.
See StabiliTrak Systemon
page 9‑53for more information.
TRAC (Traction) OFF
This message along with the
traction off light displays when the
Traction Control System (TCS) is
turned off by pressing the TCS
button. See Traction Control System
(TCS)
on page 9‑52and Traction
Control System (TCS)/StabiliTrak®
Lighton page 5‑16for more
information.

Driving and Operating 9-21
Driving in Water
{WARNING
Driving through rushing water can
be dangerous. Deep water can
sweep your vehicle downstream
and you and your passengers
could drown. If it is only shallow
water, it can still wash away the
ground from under your tires, and
you could lose traction and roll
the vehicle over. Do not drive
through rushing water.
Heavy rain can mean flash flooding,
and flood waters demand extreme
caution. Find out how deep the water is
before driving through it. Do not
try it if it is deep enough to cover
the wheel hubs, axles, or exhaust
pipe
—you probably will not get
through. Deep water can damage
the axle and other vehicle parts.
The vehicle is capable of depths up
to 50 cm (20 inches). Know how to
judge whether the water is deeper
than this before proceeding into it.
If the water is not too deep, drive
slowly through it. At faster speeds,
water splashes on the ignition
system and the vehicle can stall.
Stalling can also occur if you get the
tailpipe under water. If the tailpipe is
under water, you will never be able
to start the engine. When going
through water, remember that when
the brakes get wet, it might take
longer to stop. See Driving on Wet
Roads on page 9‑22.
After Off-Road Driving
Remove any brush or debris that
has collected on the underbody,
chassis, or under the hood. These
accumulations can be a fire hazard.
After operation in mud or sand,
have the brake linings cleaned and
checked. These substances can
cause glazing and uneven braking.
Check the engine and oil coolers
for mud accumulation. Thoroughly
and carefully clean these devices
to allow proper cooling. Check
the body structure, steering,
suspension, wheels, tires, and
exhaust system for damage and
check the fuel lines and cooling
system for any leakage.
The vehicle requires more frequent
service due to off-road use. Refer
to the Maintenance Schedule for
additional information.

Driving and Operating 9-23
Other driving tips include:
.Keep the vehicle well ventilated.
.Keep interior temperature cool.
.Keep your eyes moving—scan
the road ahead and to the sides.
.Check the rearview mirror and
vehicle instruments often.
Hill and Mountain Roads
Driving on steep hills or through
mountains is different than driving
on flat or rolling terrain. Tips for
driving in these conditions include:
.Keep the vehicle serviced and in
good shape.
.Check all fluid levels and brakes,
tires, cooling system, and
transmission.
.Going down steep or long hills,
shift to a lower gear.
{WARNING
If you do not shift down, the
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 the engine
assist the brakes on a steep
downhill slope.
{WARNING
Coasting downhill in N (Neutral)
or with the ignition off is
dangerous. The brakes will have
to do all the work of slowing down
and 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 the
engine running and the vehicle in
gear when going downhill.
.Stay in your own lane. Do not
swing wide or cut across the
center of the road. Drive at
speeds that let you stay in your
own lane.
.Top of hills: Be alert —
something could be in your
lane (stalled car, accident).
.Pay attention to special road
signs (falling rocks area, winding
roads, long grades, passing or
no-passing zones) and take
appropriate action.

Driving and Operating 9-25
WARNING (Continued)
If the vehicle is stuck in the snow:
.Clear away snow from around
the base of your vehicle,
especially any that is blocking
the exhaust pipe.
.Check again from time to
time to be sure snow does
not collect there.
.Open a window about 5 cm
(two inches) 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.(Continued)
WARNING (Continued)
For more information about
carbon monoxide, see Engine
Exhaust on page 9‑40.
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.

9-36 Driving and Operating
To prevent gear damage, this
system also prevents cranking if
the engine is already running.
Engine cranking can be stopped
by turning the ignition switch to
ACC/ACCESSORY or
LOCK/OFF.
Notice: Cranking the engine for
long periods of time, by returning
the key to the START position
immediately after cranking has
ended, can overheat and damage
the cranking motor, and drain the
battery. Wait at least 15 seconds
between each try, to let the
cranking motor cool down.
2. If the engine does not start
after 5‐10 seconds, especially
in very cold weather (below 0°F
or−18°C), it could be flooded
with too much gasoline. Push
the accelerator pedal all the way
to the floor and holding it there
as you hold the key in START
for a maximum of 15 seconds. Wait at least 15 seconds
between each try, to allow the
cranking motor to cool. When
the engine starts, let go of the
key and accelerator. If the
vehicle starts briefly but then
stops again, repeat the
procedure. This clears the extra
gasoline from the engine. Do not
race the engine immediately
after starting it. Operate the
engine and transmission gently
until the oil warms up and
lubricates all moving parts.
Notice: The engine is designed to
work with the electronics in the
vehicle. If you add electrical
parts or accessories, you could
change the way the engine
operates. Before adding electrical
equipment, check with your
dealer. If you do not, the engine
might not perform properly. Any
resulting damage would not be
covered by the vehicle warranty.Engine Coolant Heater
The engine coolant heater can
provide easier starting and better
fuel economy during engine
warm-up in cold weather conditions
at or below −18°C (0°F). Vehicles
with an engine coolant heater
should be plugged in at least
four hours before starting. An
internal thermostat in the plug-end
of the cord may exist which will
prevent engine coolant heater
operation at temperatures
above −18°C (0° F).
To Use the Engine Coolant
Heater
1. Turn off the engine.
2. Open the hood and unwrap
the electrical cord. The cord
is located in the engine
compartment behind the
underhood fuse block on the
driver side of the vehicle.

9-50 Driving and Operating
Brakes
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, and it might
even be noticed that the brake
pedal moves a little. This is normal.
If there is a problem with ABS, this
warning light stays on. SeeAntilock
Brake System (ABS) Warning Light
on page 5‑15. If driving safely on a wet road and
it becomes necessary to slam on
the brakes and continue braking
to avoid a sudden obstacle, 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 wheel.
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
ABS work. The ABS pump or motor
might be heard operating, and the
brake pedal might be felt to pulsate,
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.

Driving and Operating 9-65
Gasoline Specifications
At a minimum, gasoline should
meet ASTM specification 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. SeeFuel Additives
on page 9‑65for additional
information.
California Fuel
Requirements
If the vehicle is certified to meet
California Emissions Standards, it is
designed to operate on fuels that
meet California specifications. 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 specifications, but emission
control system performance might be affected. The malfunction
indicator lamp could turn on and the
vehicle might fail a smog‐check test.
See
Malfunction Indicator Lamp
on
page 5‑12. 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.
Fuels in Foreign
Countries
If you plan on driving in another
country outside the United States or
Canada, the proper fuel might be
hard to find. Never use leaded
gasoline or any other fuel not
recommended in the previous text
on fuel. Costly repairs caused by
use of improper fuel would not be
covered by the vehicle warranty.
To check the fuel availability, ask an
auto club, or contact a major oil
company that does business in the
country where you will be driving.
Fuel Additives
To provide cleaner air, all gasolines
in the United States are now
required to contain additives that
help prevent engine and fuel system
deposits from forming, allowing the
emission control system to work
properly. In most cases, nothing
should have to be added to the fuel.
However, some gasolines contain
only the minimum amount of
additive required to meet U.S.
Environmental Protection Agency
regulations. To help keep fuel
injectors and intake valves clean,
or if the vehicle experiences
problems due to dirty injectors or
valves, look for gasoline that is
advertised as TOP TIER Detergent
Gasoline. Look for the TOP TIER
label on the fuel pump to ensure
gasoline meets enhanced
detergency standards developed
by the auto companies. A list of
marketers providing TOP TIER
Detergent Gasoline can be found at
www.toptiergas.com.

Driving and Operating 9-71
With the added weight, the engine,
transmission, wheel assemblies and
tires are forced to work harder and
under greater loads. The trailer also
adds wind resistance, increasing
the pulling requirements. For safe
trailering, correctly use the proper
trailering equipment.
The following information has
important trailering tips and rules
for your safety and that of your
passengers. Read this section
carefully before pulling a trailer.
Pulling A Trailer
Here are some important points:
.There are many laws, including
speed limit restrictions that apply
to trailering. Check for legal
requirements with state or
provincial police.
.Consider using a sway control.
See“Hitches” later in this
section.
.Do not tow a trailer at all during
the first 800 km (500 miles) the
new vehicle is driven. The
engine, axle or other parts could
be damaged.
.Then, during the first 800 km
(500 miles) that a trailer is
towed, do not drive over 80 km/h
(50 mph) 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
transmission can tow in
D (Drive). Use a lower gear if
the transmission shifts too often.
For vehicles with a manual
transmission, it is better not to
use the highest gear.
.This vehicle has a Hill Start
Assist feature, which may be
useful when the vehicle is
stopped on a grade. See Hill
Start Assist (HSA)
on page 9‑52for more information.
.Do not drive faster than the
maximum posted speed for
trailers.
Driving with a Trailer
Towing a trailer requires experience.
Get familiar with handling and
braking with the added trailer
weight. The vehicle is now longer
and not as responsive as the
vehicle is by itself.
Check all trailer hitch parts and
attachments, safety chains,
electrical connectors, lamps, tires
and mirror adjustments. If the trailer
has electric brakes, start the vehicle
and trailer moving and then apply
the trailer brake controller by hand
to be sure the brakes are working.
During the trip, check occasionally
to be sure that the load is secure,
and the lamps and trailer brakes are
working properly.

9-74 Driving and Operating
Leaving After Parking on a Hill
1. Apply and hold the brake pedalwhile you:
.start the engine,
.shift into a gear, and
.release the parking brake.
2. Let up on the brake pedal.
3. Drive slowly until the trailer is clear of the chocks.
4. Stop and have someone pick up and store the chocks.
Maintenance When Trailer
Towing
The vehicle needs service more
often when pulling a trailer. See this
manual's Maintenance Schedule
or Index for more information.
Things that are especially important
in trailer operation are automatic
transmission fluid, engine oil, axle lubricant, belts, cooling system and
brake system. It is a good idea to
inspect these before and during
the trip.
Check periodically to see that all
hitch nuts and bolts are tight.
Engine Cooling When Trailer
Towing
The cooling system may temporarily
overheat during severe operating
conditions. See
Engine Overheating
on page 10‑22.
Trailer Towing
Three important considerations
have to do with weight:
.The weight of the trailer.
.The weight of the trailer tongue.
.The total weight on the vehicle's
tires.
Weight of the Trailer
How heavy can a trailer safely be?
Speed, altitude, road grades,
outside temperature, special
equipment, and the amount of
tongue weight the vehicle can carry
must be considered. 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.
Use the following chart to determine
how much a vehicle can weigh,
based on the vehicle model and
options.