2004 HUMMER H2 transmission

When You Are Ready to Leave After
Parking on a Hill
1. Apply your regular brakes and hold the pedal down
while you:
start your 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
Your vehicle will need service more often when you’re
pulling a trailer. See the Maintenance Schedule for more
on this. Things that are especially important in trailer
operation are automatic transmission uid (don’t overll),
engine oil, axle lubricant, belts, cooling system and
brake system. Each of these is covered in this manual,
and the Index will help you nd them quickly. If
you’re trailering, it’s a good idea to review these sections
before you start your trip.
Check periodically to see that all hitch nuts and bolts
are tight.
Trailer Wiring Harness
Heavy-Duty Trailer Wiring Package
Your vehicle is equipped with a trailer towing harness.
This harness with a seven-pin universal heavy-duty
trailer connector is attached to a bracket on the hitch
platform.
The Center High-Mounted Stoplamp (CHMSL) wire is
tied next to the trailer wiring harness for use with a
trailer.
4-84

Service............................................................5-3
Doing Your Own Service Work.........................5-4
Adding Equipment to the Outside of Your
Vehicle......................................................5-5
Fuel................................................................5-5
Gasoline Octane............................................5-5
Gasoline Specications....................................5-5
California Fuel...............................................5-6
Additives.......................................................5-6
Fuels in Foreign Countries...............................5-7
Filling Your Tank............................................5-7
Filling a Portable Fuel Container.......................5-9
Checking Things Under the Hood....................5-10
Hood Release..............................................5-10
Engine Compartment Overview.......................5-12
Engine Oil...................................................5-14
Engine Air Cleaner/Filter................................5-19
Automatic Transmission Fluid.........................5-21
Engine Coolant.............................................5-24
Coolant Surge Tank Pressure Cap..................5-27
Engine Overheating.......................................5-27
Cooling System............................................5-30Engine Fan Noise.........................................5-35
Power Steering Fluid.....................................5-36
Windshield Washer Fluid................................5-37
Brakes........................................................5-38
Battery........................................................5-42
Jump Starting...............................................5-43
All-Wheel Drive..............................................5-48
Rear Axle.......................................................5-50
Front Axle......................................................5-51
Bulb Replacement..........................................5-52
Halogen Bulbs..............................................5-52
Headlamps..................................................5-52
Front Turn Signal and Parking Lamps..............5-53
Sidemarker Lamps........................................5-54
Daytime Running Lamps................................5-54
Roof Marker Lamps......................................5-55
Center High-Mounted Stoplamp (CHMSL).........5-57
Taillamps.....................................................5-57
Replacement Bulbs.......................................5-58
Windshield Wiper Blade Replacement..............5-59
Section 5 Service and Appearance Care
5-1

A. Coolant Surge Tank. SeeCooling System on
page 5-30andCoolant Surge Tank Pressure Cap
on page 5-27.
B. Engine Air Cleaner/Filter. SeeEngine Air
Cleaner/Filter on page 5-19.
C. Windshield Washer Fluid Reservoir. SeeWindshield
Washer Fluid on page 5-37.
D. Engine Oil Fill. SeeEngine Oil on page 5-14.
E. Engine Oil Dipstick. SeeEngine Oil on page 5-14.
F. Automatic Transmission Dipstick. SeeAutomatic
Transmission Fluid on page 5-21.
G. Fan. SeeCooling System on page 5-30andEngine
Fan Noise on page 5-35.H. Remote Negative (−) Terminal (GND). SeeJump
Starting on page 5-43.
I. Power Steering Fluid Reservoir (Out of View). See
Power Steering Fluid on page 5-36.
J. Remote Positive (+) Terminal. SeeJump Starting on
page 5-43.
K. Brake Fluid Reservoir. SeeBrakes on page 5-38.
L. Underhood Fuse Block. See “Underhood Fuse Block”
underFuses and Circuit Breakers on page 5-102.
M. Battery. SeeBattery on page 5-42.
Before closing the hood, be sure all ller caps are on
properly. Pull down the hood and close it rmly.
5-13

Automatic Transmission Fluid
When to Check and Change
A good time to check your automatic transmission uid
level is when the engine oil is changed.
Change both the uid and lter every 50,000 miles
(83 000 km) if the vehicle is mainly driven under one or
more of these conditions:
In heavy city traffic where the outside temperature
regularly reaches 90°F (32°C) or higher.
In hilly or mountainous terrain.
When doing frequent trailer towing.
Uses such as found in taxi, police or delivery
service.
If you do not use your vehicle under any of these
conditions, change the uid and lter every
100,000 miles (166 000 km).
SeeScheduled Maintenance on page 6-4.
How to Check
Because this operation can be a little difficult, you may
choose to have this done at the dealership service
department.
If you do it yourself, be sure to follow all the instructions
here, or you could get a false reading on the dipstick.
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
part 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.
Wait at least 30 minutes before checking the
transmission uid level if you have been driving:
When outside temperatures are above 90°F (32°C).
At high speed for quite a while.
In heavy traffic – especially in hot weather.
While pulling a trailer.
To get the right reading, the uid should be at normal
operating temperature, which is 180°F to 200°F
(82°C to 93°C).
5-21

Get the vehicle warmed up by driving about 15 miles
(24 km) when outside temperatures are above 50°F
(10°C). If it’s colder than 50°F (10°C), drive the vehicle
in THIRD (3) until the engine temperature gage
moves and then remains steady for 10 minutes.
A cold uid check can be made after the vehicle has
been sitting for eight hours or more with the engine off,
but this is used only as a reference. Let the engine
run at idle for ve minutes if outside temperatures are
50°F (10°C) or more. If it’s colder than 50°F (10°C), you
may have to idle the engine longer. Should the uid
level be low during this cold check, youmustcheck the
uid hot before adding uid. Checking the uid hot
will give you a more accurate reading of the uid level.
Checking the Fluid Level
Prepare your vehicle as follows:
Park your vehicle on a level place. Keep the engine
running.
With the parking brake applied, place the shift lever
in PARK (P).
With your foot on the brake pedal, move the shift
lever through each gear range, pausing for about
three seconds in each range. Then, position the shift
lever in PARK (P).
Let the engine run at idle for three minutes or more.
Then, without shutting off the engine, follow these
steps:
The transmission dipstick
handle with the graphic is
located at the rear of
the engine compartment,
on the passenger’s side.
SeeEngine Compartment Overview on page 5-12for
more information on location.
1. Flip the handle up and then pull out the dipstick
and wipe it with a clean rag or paper towel.
2. Push it back in all the way, wait three seconds and
then pull it back out again.
5-22

3. Check both sides of the dipstick, and read the lower
level. The uid level must be in the COLD area,
below the cross-hatched area, for a cold check or in
the HOT area or cross-hatched area for a hot
check. Be sure to keep the dipstick pointed down to
get an accurate reading.
4. 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.
How to Add Fluid
Refer to the Maintenance Schedule to determine what
kind of transmission uid to use. SeeRecommended
Fluids and Lubricants on page 6-12.
Add uid only after checking the transmission uid while it
is hot. (A cold check is used only as a reference.) If the
uid level is low, add only enough of the proper uid to
bring the level up to the HOT area for a hot check. It
doesn’t take much uid, generally less than one pint
(0.5 L).Don’t overll.
Notice:We recommend you use only uid labeled
DEXRON
®-III, because uid with that label is
made especially for your automatic transmission.
Damage caused by uid other than DEXRON
®-III is
not covered by your new vehicle warranty.
After adding uid, recheck the uid level as
described underHow to Check.
When the correct uid level is obtained, push the
dipstick back in all the way; then ip the handle
down to lock the dipstick in place.
5-23

5. With the coolant surge tank pressure cap off, start
the engine and let it run until you can feel the upper
radiator hose getting hot. Watch out for the
engine cooling fan.
By this time, the coolant level inside the coolant
surge tank may be lower. If the level is lower, add
more of the proper mixture to the coolant surge tank
until the level reaches FULL COLD mark.
6. Then replace the pressure cap. Be sure the
pressure cap is hand-tight and fully seated.
Engine Fan Noise
Your vehicle has a clutched engine cooling fan. When
the clutch is engaged, the fan spins faster to provide
more air to cool the engine.
In most everyday driving conditions, the fan is spinning
slower and the clutch is not fully engaged. This
improves fuel economy and reduces fan noise. Under
heavy vehicle loading, trailer towing and/or high outside
temperatures, the fan speed increases as the clutch
more fully engages. So you may hear an increase in fan
noise. This is normal and should not be mistaken as
the transmission slipping or making extra shifts. It
is merely the cooling system functioning properly. The
fan will slow down when additional cooling is not
required and the clutch disengages.
You may also hear this fan noise when you start the
engine. It will go away as the fan clutch partially
disengages.
5-35

2. Get the vehicles close enough so the jumper cables
can reach, but be sure the vehicles aren’t touching
each other. If they are, it could cause a ground
connection you don’t want. You wouldn’t be able to
start your vehicle, and the bad grounding could
damage the electrical systems.
To avoid the possibility of the vehicles rolling, set
the parking brake rmly on both vehicles involved in
the jump start procedure. Put an automatic
transmission in PARK (P) or a manual transmission
in NEUTRAL before setting the parking brake.
Notice:If you leave your radio or other accessories
on during the jump starting procedure, they could
be damaged. The repairs would not be covered
by your warranty. Always turn off your radio and
other accessories when jump starting your vehicle.
3. Turn off the ignition on both vehicles. Unplug
unnecessary accessories plugged into the cigarette
lighter or accessory power outlets. Turn off the radio
and all lamps that aren’t needed. This will avoid
sparks and help save both batteries. And it could
save your radio!4. Open the hoods and locate the positive (+) and
negative (−) terminal locations of the other vehicle.
Your vehicle has a remote positive (+) jump
starting terminal and a remote negative (−) jump
starting terminal. You should always use these
remote terminals instead of the terminals on the
battery.
The remote positive (+)
terminal is located near the
engine accessory drive
bracket. On some vehicles,
the terminal may be
covered under under a red
plastic cover. To access
the remote positive (+)
terminal, open the
red plastic cover.
5-44