engine overheat HUMMER H2 2007 Owners Manual

Your vehicle has a Computer-Controlled
Cranking System. This feature assists in
starting the engine and protects components. If
the ignition key is turned to the START position,
and then released when the engine begins
cranking, the engine will continue cranking for a
few seconds or until the vehicle starts. If the
engine does not start and the key is held in
START for many seconds, cranking will be
stopped after 15 seconds to prevent cranking
motor damage. 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 the
ACCESSORY or LOCK position.
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 allow
the cranking motor to 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 ooded with too much
gasoline. Try pushing the accelerator
pedal all the way to the oor and holding it
there as you hold the key in START for up to
a maximum of 15 seconds. Wait at least
15 seconds between each try, to allow the
cranking motor to cool down. When the engine
starts, let go of the key and accelerator. If
the vehicle starts briey but then stops again,
do the same thing. 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:Your engine is designed to work with
the electronics in your 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, your engine might
not perform properly. Any resulting damage
would not be covered by your vehicle’s
warranty.
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Engine Coolant Heater
Your vehicle may be equipped with an engine
coolant heater.
In very cold weather, 0°F (−18°C) or colder, the
engine coolant heater can help. You will get easier
starting and better fuel economy during engine
warm-up.
Usually, the coolant heater should be plugged in a
minimum of four hours prior to starting your
vehicle. At temperatures above 32°F (0°C), use of
the coolant heater is not required. Your vehicle
may also have an internal thermostat in the
plug end of the cord. This will prevent operation of
the engine coolant heater when the temperature
is at or above 0°F (-18°C) as noted on the cord.
To Use the Engine Coolant Heater
1. Turn off the engine.
2. Locate the electrical cord near the front
recovery loop on the driver’s side of the
vehicle.
3. Plug it into a normal, grounded 110-volt AC
outlet.
{CAUTION:
Plugging the cord into an ungrounded
outlet could cause an electrical shock.
Also, the wrong kind of extension cord
could overheat and cause a re. 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 as it was before to keep it
away from moving engine parts. If you do
not, it could be damaged.
How long should you keep the coolant heater
plugged in? The answer depends on the outside
temperature, the kind of oil you have, and
some other things. Instead of trying to list
everything here, we ask that you contact your
dealer in the area where you will be parking your
vehicle. The dealer can give you the best
advice for that particular area.
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Shifting Into Park (P)
{CAUTION:
It can be dangerous to get out of your
vehicle if the shift lever is not fully in
PARK (P) with the parking brake rmly
set. Your vehicle can roll. If you have left
the engine running, the vehicle can move
suddenly. You or others could be injured.
To be sure your vehicle will not move,
even when you are on fairly level ground,
use the steps that follow. If you are
pulling a trailer, seeTowing a Trailer on
page 374.
1. Hold the brake pedal down with your right foot
and set the parking brake.
2. Move the shift lever into PARK (P) by pressing
and holding the button on the end of the shift
lever and moving the lever forward as far
as it will go.3. Turn the ignition key to LOCK.
4. Remove the key and take it with you. If you
can leave your vehicle with the ignition key in
your hand, your vehicle is in PARK (P).Leaving Your Vehicle With the Engine
Running
{CAUTION:
It can be dangerous to leave your vehicle
with the engine running. Your vehicle
could move suddenly if the shift lever is
not fully in PARK (P) with the parking
brake rmly set. And, if you leave the
vehicle with the engine running, it could
overheat and even catch re. You or
others could be injured. Do not leave your
vehicle with the engine running.
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Anti-Lock Brake System
Warning Light
With the Anti-Lock Brake
System (ABS), this light
will come on when you
start your engine and
may stay on for several
seconds.
That is normal. If the light does not come on then,
have it xed so it will be ready to warn you if
there is a problem.
If the light stays on, or comes on when you are
driving, your vehicle needs service. A chime
will sound when the light stays on. If the regular
brake system warning light is not on, you still have
brakes, but you do not have ABS. If the regular
brake system warning light is also on you do
not have ABS and there is a problem with your
regular brakes. In addition to both lights, you
will also hear a chime sound on the rst
occurrence of a problem and each time the
vehicle is shut off and then restarted. SeeBrake
System Warning Light on page 211.The ABS warning light should come on briey
when you turn the ignition key to RUN. If the light
does not come on then, have it xed so it will
be ready to warn you if there is a problem.
Traction Off Light
The traction off light will
come on when a traction
control system or
anti-lock brake system
problem has been
detected. The vehicle
may need service.
When this light is on, the system will not limit
wheel spin. Adjust your driving accordingly. See
Traction Control System (TCS) on page 309.
If the Traction Control System (TCS) detects that
the vehicle’s brake’s are overheating, the TCS will
shut off and the traction off light will come on. When
the brakes cool off, the TCS will turn back on
automatically and the traction off light will go out.
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Engine Coolant Temperature Gage
This gage shows the engine coolant temperature.
It also provides an indicator of how hard your
vehicle is working. During a majority of the
operation, the gage will read 210°F (100°C) or less.
If you are pulling a load or going up hills, it is normal
for the temperature to uctuate and approach the
250°F (122°C) mark. If the gage reaches the 260°F
(125°C) mark, it indicates that the cooling system is
working beyond its capacity.
SeeEngine Overheating on page 418.
Transmission Temperature Gage
Your vehicle has a transmission temperature gage.
When your ignition is on, the gage shows the
temperature of the transmission uid. The normal
operating range is from 180°F (82°C) to about
200°F (93°C).
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ENGINE COOLANT HOT
This message displays if the cooling system
temperature gets hot. Turn off the air conditioning.
If the message is still on, or if the engine coolant
temperature gage continues to rise, pull the vehicle
over when it is safe to do so. SeeEngine
Coolant Temperature Gage on page 213for more
information. Stop the vehicle and let the engine
idle in PARK (P) for a few minutes to allow
the coolant to reach a safe temperature. This
message clears when the coolant temperature
drops to a safe operating temperature. Press any
of the DIC buttons, or the trip stem, to
acknowledge this message and clear it from the
DIC display.
ENGINE OVERHEATED
This message displays and a chime sounds if the
engine cooling system reaches unsafe
temperatures for operation. Stop and turn off the
vehicle as soon as it is safe to do so to avoid
severe damage. This message clears when the
engine has cooled to a safe operating temperature.
FUEL LEVEL LOW
This message displays and a chime sounds if the
fuel level is low. Refuel as soon as possible.
Press any of the DIC buttons, or the trip stem, to
acknowledge this message and clear it from
the DIC display. This message also clears itself
after 10 seconds. The low fuel light near the
fuel gage still remains on in either case. SeeLow
Fuel Warning Light on page 221,Fuel Gage on
page 221, andFuel on page 394for more
information.
KEYFOB X BATTERY LOW
This message displays if a Remote Keyless
Entry (RKE) transmitter battery is low. Replace
the battery in the transmitter. See “Battery
Replacement” underRemote Keyless Entry (RKE)
System Operation on page 97. Press any of the
DIC buttons, or the trip stem, to acknowledge this
message and clear it from the DIC display.
228

REDUCED ENGINE POWER
This message displays when the cooling system
temperature gets too hot and the engine further
enters the engine coolant protection mode.
SeeEngine Overheating on page 418for further
information.
This message may also display when the vehicle
determines that there is a problem with the
electronic throttle control. See your dealer
for service.
This message also 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.
REPLACE LIFTGATE FUSE (SUV)
This message displays if the liftgate lock
malfunctions and/or the liftgate fuse blows. For
more information on fuses, seeInstrument Panel
Fuse Block on page 504andUnderhood Fuse
Block on page 507.
If the message returns after replacing the fuse,
see your dealer for service.
RIGHT REAR DOOR AJAR
This message displays and a chime sounds if the
passenger’s side rear door is not fully closed
and the vehicle is in a drive gear. Stop and turn
off the vehicle, check the door for obstructions, and
close the door again. Check to see if the
message still appears on the DIC. Press any of
the DIC buttons, or the trip stem, to acknowledge
this message and clear it from the DIC display.
230

TIGHTEN FUEL CAP
This message may display along with the check
engine light on the instrument panel cluster if
the vehicle’s fuel cap is not tightened properly.
SeeMalfunction Indicator Lamp on page 215.
Reinstall the fuel cap, making sure to fully install
the cap. SeeFilling the Tank on page 397.
The diagnostic system can determine if the fuel
cap has been left off or improperly installed.
A loose or missing fuel cap allows fuel to
evaporate into the atmosphere. A few driving trips
with the cap properly installed should turn the
light and message off.
TRACTION ACTIVE
This message displays when the Traction Control
System (TCS) is active. This happens when
the TCS has detected that any of the vehicle’s
wheels are slipping. SeeTraction Control
System (TCS) on page 309for more information.
TRANS (Transmission) HOT IDLE
ENGINE
Notice:If you drive your vehicle while the
transmission uid is overheating and the
transmission temperature warning is displayed
on the instrument panel cluster and/or DIC, you
can damage the transmission. This could lead
to costly repairs that would not be covered by
your warranty. Do not drive your vehicle with
overheated transmission uid or while the
transmission temperature warning is displayed.
This message displays and a continuous chime
sounds if the transmission uid in the vehicle gets
hot. Driving with the transmission uid temperature
high can cause damage to the vehicle. Stop the
vehicle and let it idle to allow the transmission
to cool. This message clears and the chime stops
when the uid temperature reaches a safe
level. SeeTransmission Temperature Gage on
page 213.
232

Driving Downhill
When off-roading takes you downhill, you will want
to consider a number of things:
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, then
try to keep your vehicle headed straight down, and
use a low gear. This way, engine drag can help
your brakes and they will not have to do all
the work. Descend slowly, keeping your 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.
332

Q:Are there some things I should not do
when driving down a hill?
A:Yes! These are important because if you
ignore them you could lose control and
have a serious accident:
When driving downhill, avoid turns that take
you across the incline of the hill. A hill that
is not too steep to drive down may be
too steep to drive across. You could roll over
if you do not drive straight down.
Never go downhill with the transmission in
NEUTRAL (N). This is called “free-wheeling.”
Your brakes will have to do all the work
and could overheat and fade.
Q:Am I likely to stall when going downhill?
A:It is much more likely to happen going
uphill. But if it happens going downhill, here is
what to do:
1. Stop your vehicle by applying the regular
brakes. Apply the parking brake.
2. Shift to PARK (P) 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.
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