engine overheat HUMMER H3 2010 Owners Manual

Instruments and Controls 5-9
Engine Coolant
Temperature Gauge
United StatesCanada
This gauge shows the engine
coolant temperature.
If the gauge pointer is in the shaded
area of the gauge, the engine is
too hot. It means that the engine
coolant has overheated. If the
vehicle has been operating under
normal driving conditions, pull off
the road, stop your vehicle and turn
off the engine as soon as possible.
See Engine Overheating
on
page 10‑22for more information.
Safety Belt Reminders
Driver Safety Belt Reminder
Light
There is a driver safety belt
reminder light on the instrument
panel cluster.
When the engine is started this
light and a chime come on and stay
on for several seconds to remind
drivers to fasten their safety belts.
The light also begins to flash.
This cycle repeats if the driver
remains unbuckled and the vehicle
is moving.
If the driver safety belt is already
buckled, neither the light nor chime
come on.
Passenger Safety Belt
Reminder Light
The passenger safety belt reminder
light is by the passenger airbag
status indicator.
When the engine is started this light
and the chime come on and stay on
for several seconds to remind the
passenger to fasten their safety belt.
The light also begins to flash.
This cycle repeats if the passenger
remains unbuckled and the vehicle
is moving.
If the passenger safety belt is
buckled, neither the chime nor the
light comes on.

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.

9-18 Driving and Operating
Driving Downhill
When off-roading takes you
downhill, consider:
.How steep is the downhill?
Will I be able to maintain vehicle
control?
.What is the surface like?
Smooth? Rough? Slippery?
Hard-packed dirt? Gravel?
.Are there hidden surface
obstacles? Ruts? Logs?
Boulders?
.What is at the bottom of the hill?
Is there a hidden creek bank or
even a river bottom with large
rocks?
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.
{WARNING
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. With an automatic transmission, shift to P (Park). 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.

9-26 Driving and Operating
If the Vehicle is Stuck
Slowly and cautiously spin the
wheels to free the vehicle when
stuck in sand, mud, ice, or snow.
If stuck too severely for the traction
system to free the vehicle, turn the
traction system off and use the
rocking method.
{WARNING
If the 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 55 km/h (35 mph) as
shown on the speedometer.
For information about using tire
chains on the vehicle, see Tire
Chains on page 10‑64.
Rocking the Vehicle to Get
it Out
Turn the steering wheel left and
right to clear the area around the
front wheels. Turn off any traction
system. Shift back and forth
between R (Reverse) and a forward
gear, or with a manual transmission,
between 1 (First) or 2 (Second) and
R (Reverse), 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. The
recovery loops can be used. If the
vehicle does need to be towed out,
see Towing the Vehicle
on
page 10‑90. Recovery Loops
{WARNING
These loops, when used, are
under a lot of force. Keep people
away from the vicinity of the loops
and any chains or cables during
use. Always pull the vehicle
straight out. Never pull on the
loops at a sideways angle. The
loops could break off and you or
others could be injured from the
chain or cable snapping back.
Notice: Never use the recovery
loops to tow the vehicle. The
vehicle could be damaged and
it would not be covered by the
vehicle warranty.

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.

Driving and Operating 9-37
3. Plug it into a normal, grounded110-volt AC outlet.
{WARNING
Plugging the cord into an
ungrounded outlet could cause an
electrical shock. Also, the wrong
kind of extension cord could
overheat and cause a fire. You
could be seriously injured. Plug
the cord into a properly grounded
three-prong 110-volt AC outlet.
If the cord will not reach, use a
heavy-duty three-prong extension
cord rated for at least 15 amps.
4. Before starting the engine, be sure to unplug and store the
cord to prevent damage.
The length of time the heater should
remain plugged in depends on
several factors. Ask a dealer in the
area where you will be parking the
vehicle for the best advice on this.
Shifting Into Park
{WARNING
It can be dangerous to get out of
the vehicle if the shift lever is not
fully in P (Park) with the parking
brake firmly set. The vehicle can
roll. If you have left the engine
running, the vehicle can move
suddenly. You or others could be
injured. To be sure the vehicle will
not move, even when you are on
fairly level ground, use the steps
that follow. If you are pulling a
trailer, see Driving Characteristics
and Towing Tips on page 9‑70.
1. Hold the brake pedal down, then set the parking brake.
See Parking Brake
on
page 9‑51for more information.
{WARNING
With all-wheel drive, the vehicle
will be free to roll —even if the
shift lever is in P (Park) —if the
transfer case is in Neutral. So, be
sure the transfer case is in a drive
gear, four-wheel high (4H) or
four-wheel low (4L) —not in
Neutral.
2. Move the shift lever into P (Park) by pressing the shift lever button
and moving the lever as far
forward as it will go.
3. Turn the ignition key to LOCK/OFF.
4. Remove the key from the ignition.

9-38 Driving and Operating
Leaving Your Vehicle With the
Engine Running (Automatic
Transmission)
{WARNING
It can be dangerous to leave the
vehicle with the engine running.
The vehicle could move suddenly
if the shift lever is not fully in
P (Park) with the parking brake
firmly set. And, if you leave the
vehicle with the engine running, it
could overheat and even catch
fire. You or others could be
injured. Do not leave the vehicle
with the engine running.If you have to leave the vehicle with
the engine running, be sure the
vehicle is in P (Park) and the
parking brake is firmly set before
you leave it. After you have moved
the shift lever into P (Park), hold
the regular brake pedal down.
Then, see if you can move the shift
lever away from P (Park) without
first pressing the shift lever button.
If you can, it means that the shift
lever was not fully locked into
P (Park).
Torque lock is when the weight
of the vehicle puts too much
force on the parking pawl in the
transmission. This happens when
parking on a hill and shifting the
transmission into P (Park) is not
done properly and then it is difficult
to shift out of P (Park). To prevent
torque lock, set the parking brake
and then shift into P (Park). To find
out how, see
“Shifting Into P (Park)”
listed previously. If torque lock does occur, your
vehicle may need to be pushed
uphill by another vehicle to relieve
the parking pawl pressure, so you
can shift out of P (Park).Shifting Out of Park
This vehicle is equipped with an
electronic shift lock release system.
The shift lock release is
designed to:
.Prevent ignition key removal
unless the shift lever is in
P (Park) with the shift lever
button fully released, and
.Prevent movement of the shift
lever out of P (Park) unless
the ignition is in ON/RUN or
ACC/ACCESSORY and the
regular brake pedal is applied.

Driving and Operating 9-73
Vehicles with an automatic
transmission 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. For vehicles with a
manual transmission, it is better not
to use the highest gear.
When towing at high altitude on
steep uphill grades, consider the
following: Engine coolant will boil at
a lower temperature than at normal
altitudes. If the engine is turned off
immediately after towing at high
altitude on steep uphill grades, the
vehicle may show signs similar to
engine overheating. To avoid this,
let the engine run while parked,
preferably on level ground, with the
automatic transmission in P (Park)
for a few minutes before turning the
engine off. For vehicles with manualtransmissions, let the engine run
while parked, preferably on level
ground, with the transmission out of
gear and the parking brake applied,
for a few minutes before turning the
engine off. If the overheat warning
comes on, see
Engine Overheating
on page 10‑22.
Parking on Hills
{WARNING
Parking the vehicle on a hill
with the trailer attached can be
dangerous. If something goes
wrong, the rig could start to move.
People can be injured, and both
the vehicle and the trailer can be
damaged. When possible, always
park the rig on a flat surface. If parking the rig on a hill:
1. Press the brake pedal, but do
not shift into P (Park) yet for
vehicles with an automatic
transmission, or into gear
for vehicles with a manual
transmission. Turn the wheels
into the curb if facing downhill
or into traffic if facing uphill.
2. Have someone place chocks under the trailer wheels.
3. When the wheel chocks are in place, release the brake pedal
until the chocks absorb the load.
4. Reapply the brake pedal. Then apply the parking brake and shift
into P (Park) for vehicles with an
automatic transmission or into
gear for vehicles with a manual
transmission.
5. Release the brake pedal.

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.

Vehicle Care 10-1
Vehicle Care
General Information
General Information . . . . . . . . . . 10-2
California Proposition65 Warning . . . . . . . . . . . . . . . . . 10-2
California Perchlorate Materials Requirements . . . . 10-3
Accessories and Modifications . . . . . . . . . . . . . . . 10-3
Vehicle Checks
Doing Your OwnService Work . . . . . . . . . . . . . . . 10-4
Hood . . . . . . . . . . . . . . . . . . . . . . . . 10-5
Engine Compartment Overview . . . . . . . . . . . . . . . . . . . 10-6
Engine Oil . . . . . . . . . . . . . . . . . . . 10-9
Engine Oil Life System . . . . . 10-11
Automatic Transmission Fluid . . . . . . . . . . . . . . . . . . . . . . 10-12
Manual Transmission Fluid . . . . . . . . . . . . . . . . . . . . . . 10-15 Hydraulic Clutch . . . . . . . . . . . . 10-16
Engine Air Cleaner/Filter . . . . 10-17
Cooling System . . . . . . . . . . . . 10-18
Engine Coolant . . . . . . . . . . . . . 10-19
Engine Overheating . . . . . . . . 10-22
Engine Fan . . . . . . . . . . . . . . . . . 10-24
Power Steering Fluid . . . . . . . 10-24
Washer Fluid . . . . . . . . . . . . . . . 10-25
Brakes . . . . . . . . . . . . . . . . . . . . . 10-26
Brake Fluid . . . . . . . . . . . . . . . . . 10-27
Battery . . . . . . . . . . . . . . . . . . . . . 10-28
Four-Wheel Drive . . . . . . . . . . . 10-29
Front Axle . . . . . . . . . . . . . . . . . . 10-29
Rear Axle . . . . . . . . . . . . . . . . . . 10-29
Starter Switch Check . . . . . . . 10-30
Automatic Transmission Shift
Lock Control System
Check . . . . . . . . . . . . . . . . . . . . . 10-30
Ignition Transmission Lock Check . . . . . . . . . . . . . . . . . . . . . 10-31
Park Brake and P (Park) Mechanism Check . . . . . . . . 10-31
Wiper Blade Replacement . . . . . . . . . . . . . . 10-32
Headlamp Aiming
Headlamp Aiming . . . . . . . . . . 10-33
Bulb Replacement
Bulb Replacement . . . . . . . . . . 10-35
Halogen Bulbs . . . . . . . . . . . . . . 10-35
Headlamps . . . . . . . . . . . . . . . . . 10-35
Taillamps, Turn Signal,Stoplamps, and Back-Up
Lamps (H3) . . . . . . . . . . . . . . . 10-35
Taillamps, Turn Signal, Stoplamps, and Back-Up
Lamps (H3T) . . . . . . . . . . . . . . 10-36
License Plate Lamp . . . . . . . . 10-37
Replacement Bulbs . . . . . . . . . 10-37
Electrical System
Electrical System Overload . . . . . . . . . . . . . . . . . . 10-38
Fuses and Circuit Breakers . . . . . . . . . . . . . . . . . . 10-39
Engine Compartment Fuse Block . . . . . . . . . . . . . . . . . . . . . 10-39