2009 HUMMER H2 check engine

{CAUTION:
Operating the engine with the air cleaner/lter off
can cause you or others to be burned. The air
cleaner not only cleans the air; it helps to stop
ames if the engine backres. If it is not there and
the engine backres, you could be burned. Do not
drive with it off, and be careful working on the
engine with the air cleaner/lter off.
Notice:If the air cleaner/lter is off, a backre can
cause a damaging engine re. And, dirt can easily get
into the engine, which will damage it. Always have
the air cleaner/lter in place when you are driving.
Automatic Transmission Fluid
When to Check and Change Automatic
Transmission Fluid
It is usually not necessary to check the transmission uid
level. The only reason for uid loss is a transmission leak
or overheating the transmission. If you suspect a small
leak, then use the following checking procedures to check
the uid level. However, if there is a large leak, then it
may be necessary to have the vehicle towed to a dealer/
retailer service department and have it repaired before
driving the vehicle further.
Notice:Use of the incorrect automatic transmission
uid may damage the vehicle, and the damages may
not be covered by the vehicle’s warranty. Always
use the automatic transmission uid listed in
Recommended Fluids and Lubricants on page 6-13.
Change the uid and lter at the intervals listed in the
Maintenance Schedule. SeeScheduled Maintenance on
page 6-4. Be sure to use the transmission uid listed
inRecommended Fluids and Lubricants on page 6-13.
5-23

How to Check Automatic Transmission
Fluid
Notice:Too much or too little uid can damage
your transmission. Too much can mean that some
of the uid could come out and fall on hot engine
parts or exhaust system parts, starting a re. Too
little uid could cause the transmission to overheat.
Be sure to get an accurate reading if you check your
transmission uid.
Before checking the uid level, prepare the vehicle as
follows:
1. Start the engine and park the vehicle on a level
surface. Keep the engine running.
2. Apply the parking brake and place the shift lever in
P (Park).
3. With your foot on the brake pedal, move the shift
lever through each gear range, pausing for about
three seconds in each range. Then, move the
shift lever back to P (Park).
4. Allow the engine to idle (500 – 800 rpm) for at least
one minute. Slowly release the brake pedal.
5. Keep the engine running and press the Trip/Fuel
button or trip odometer reset stem until TRANS
TEMP (Transmission Temperature) displays on the
Driver Information Center (DIC).6. Using the TRANS TEMP reading, determine and
perform the appropriate check procedure. If the
TRANS TEMP reading is not within the required
temperature ranges, allow the vehicle to cool,
or operate the vehicle until the appropriate
transmission uid temperature is reached.
Cold Check Procedure
Use this procedure only as a reference to determine if
the transmission has enough uid to be operated
safely until a hot check procedure can be made. The
hot check procedure is the most accurate method
to check the uid level. Perform the hot check procedure
at the rst opportunity. Use this cold check procedure
to check uid level when the transmission temperature is
between 80°F and 90°F (27°C and 32°C).
1. Locate the transmission
dipstick at the
rear of the engine
compartment, on
the passenger side
of the vehicle.
SeeEngine Compartment Overview on page 5-14
for more information.
2. Flip the handle up, and then pull out the dipstick
and wipe it with a clean rag or paper towel.
5-24

3. Install the dipstick by pushing it back in all the way,
wait three seconds, and then pull it back out again.
4. Check both sides of the dipstick, and read the lower
level. Repeat the check procedure to verify the
reading.
5. If the uid level is below the COLD check band,
add only enough uid as necessary to bring the
level into the COLD band. It does not take
much uid, generally less than one pint (0.5L).
Do not overll.
6. Perform a hot check at the rst opportunity after
the transmission reaches a normal operating
temperature between 160°F to 200°F (71°C to 93°C).
7. If the uid level is in the acceptable range, push the
dipstick back in all the way, then ip the handle
down to lock the dipstick in place.Hot Check Procedure
Use this procedure to check the transmission uid level
when the transmission uid temperature is between
160°F and 200°F (71°C and 93°C).
The hot check is the most accurate method to check the
uid level. The hot check should be performed at the rst
opportunity in order to verify the cold check. The uid
level rises as uid temperature increases, so it is
important to ensure the transmission temperature is
within range.
1. Locate the transmission
dipstick at the
rear of the engine
compartment, on the
passenger side of
the vehicle.
SeeEngine Compartment Overview on page 5-14
for more information.
2. Flip the handle up, and then pull out the dipstick
and wipe it with a clean rag or paper towel.
3. Install the dipstick by pushing it back in all the way,
wait three seconds, and then pull it back out again.
4. Check both sides of the dipstick, and read the lower
level. Repeat the check procedure to verify the
reading.
5-25

Cooling System
When you decide it is safe to lift the hood, here is what
you will see:
A. Coolant Surge Tank
B. Coolant Surge Tank Pressure Cap
C. Engine Cooling Fan{CAUTION:
An electric fan under the hood can start up and
injure you even when the engine is not running.
Keep hands, clothing, and tools away from any
underhood electric fan.
If the coolant inside the coolant surge tank is boiling, do
not do anything else until it cools down. The vehicle
should be parked on a level surface. Check the coolant
level after the system cools down. Some amount of
coolant may be lost due to overheating.
5-27

The coolant level should be at or above the FULL
COLD mark. If it is not, you may have a leak at the
pressure cap or in the radiator hoses, heater hoses,
radiator, water pump, or somewhere else in the cooling
system.
{CAUTION:
Heater and radiator hoses, and other engine parts,
can be very hot. Do not touch them. If you do, you
can be burned.
Do not run the engine if there is a leak. If you run
the engine, it could lose all coolant. That could
cause an engine re, and you could be burned.
Get any leak xed before you drive the vehicle.
If there seems to be no leak, start the engine again.
The engine cooling fan speed should increase when idle
speed is doubled by pushing the accelerator pedal down.
If it does not, the vehicle needs service. Turn off the
engine.Notice:Engine damage from running your engine
without coolant is not covered by your warranty. See
Overheated Engine Protection Operating Mode on
page 5-35for information on driving to a safe place
in an emergency.
Notice:Using coolant other than DEX-COOL
®can
cause premature engine, heater core, or radiator
corrosion. In addition, the engine coolant could
require changing sooner, at 30,000 miles (50 000 km)
or 24 months, whichever occurs rst. Any repairs
would not be covered by the vehicle warranty.
Always use DEX-COOL
®(silicate-free) coolant in
the vehicle.
How to Add Coolant to the Coolant
Surge Tank
If you have not found a problem yet, check to see if
coolant is visible in the surge tank. If coolant is visible
but the coolant level is not at or above the FULL COLD
mark, add a 50/50 mixture of clean, drinkable water
and DEX-COOL
®coolant at the coolant surge tank, but
be sure the cooling system, including the coolant
surge tank pressure cap, is cool before you do it. See
Engine Coolant on page 5-31for more information.
5-28

What Kind of Coolant to Use
Use a mixture of one-half clean, drinkable water and
one-half DEX-COOL®coolant which will not damage
aluminum parts. If you use this coolant mixture, you do
not need to add anything else.
{CAUTION:
Adding only plain water to the cooling system can
be dangerous. Plain water, or some other liquid
such as alcohol, can boil before the proper coolant
mixture will. The vehicle’s coolant warning system
is set for the proper coolant mixture. With plain
water or the wrong mixture, the engine could get
too hot but would not get the overheat warning.
The engine could catch re and you or others
could be burned. Use a 50/50 mixture of clean,
drinkable water and DEX-COOL
®coolant.Notice:If an improper coolant mixture is used, the
engine could overheat and be badly damaged. The
repair cost would not be covered by the vehicle
warranty. Too much water in the mixture can freeze
and crack the engine, radiator, heater core, and other
parts.
If you have to add coolant more than four times a year,
have your dealer/retailer check the cooling system.
Notice:If extra inhibitors and/or additives are used
in the vehicle’s cooling system, the vehicle could
be damaged. Use only the proper mixture of
the engine coolant listed in this manual for the
cooling system. SeeRecommended Fluids and
Lubricants on page 6-13for more information.
5-32

Checking Coolant
The coolant surge tank is
located in the engine
compartment on the
passenger side of the
vehicle. SeeEngine
Compartment Overview on
page 5-14for more
information on location.
{CAUTION:
Turning the surge tank pressure cap when the
engine and radiator are hot can allow steam and
scalding liquids to blow out and burn you badly.
Never turn the surge tank pressure cap — even a
little — when the engine and radiator are hot.
The vehicle must be on a level surface. When the
engine is cold, the coolant level should be at the FULL
COLD mark.
Adding Coolant
If you need more coolant, add the proper DEX-COOL®
coolant mixture at the surge tank, but only when the
engine is cool.
{CAUTION:
You can be burned if you spill coolant on hot
engine parts. Coolant contains ethylene glycol,
and it will burn if the engine parts are hot enough.
Do not spill coolant on a hot engine.
When replacing the pressure cap, make sure it is
hand-tight and fully seated.
Engine Overheating
You will nd a coolant temperature gage on the vehicle’s
instrument panel. SeeEngine Coolant Temperature
Gage on page 3-39.
In addition, you will nd an ENGINE OVERHEATED
IDLE ENGINE and an ENGINE POWER IS REDUCED
message in the Driver Information Center (DIC) on
the instrument panel. SeeDIC Warnings and Messages
on page 3-56.
5-33

Power Steering Fluid
SeeEngine Compartment
Overview on page 5-14for
reservoir location.
When to Check Power Steering Fluid
It is not necessary to regularly check power steering uid
unless you suspect there is a leak in the system or
you hear an unusual noise. A uid loss in this system
could indicate a problem. Have the system inspected
and repaired.
How to Check Power Steering Fluid
To check the power steering uid:
1. Turn the key off and let the engine compartment
cool down.
2. Wipe the cap and the top of the reservoir clean.
3. Unscrew the cap and wipe the dipstick with a
clean rag.
4. Replace the cap and completely tighten it.
5. Remove the cap again and look at the uid level on
the dipstick.
The level should be at the FULL COLD mark. If
necessary, add only enough uid to bring the level
up to the mark.
What to Use
To determine what kind of uid to use, see
Recommended Fluids and Lubricants on page 6-13.
Always use the proper uid.
Notice:Use of the incorrect uid may damage the
vehicle and the damages may not be covered by
the vehicle’s warranty. Always use the correct uid
listed inRecommended Fluids and Lubricants
on page 6-13.
5-36