ignition HUMMER H2 2004 Repair Manual

Driving in Water
Heavy rain can mean ash ooding, and ood waters
demand extreme caution.
Find out how deep the water is before you drive through
it. If it is deep enough to cover your wheel hubs,
axles or exhaust pipe, do not try it — you probably will
not get through. Also, water that deep can damage
your axle and other vehicle parts. Your vehicle is
capable of depths up to 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 your ignition
system and your vehicle can stall. Stalling can also
occur if you get your tailpipe under water. And, as long
as your tailpipe is under water, you will never be
able to start your engine. When you go through water,
remember that when your brakes get wet, it may
take you longer to stop.{CAUTION:
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.
SeeDriving in Rain and on Wet Roads on page 4-43for
more information on driving through water.
4-40

{CAUTION:
Coasting downhill in NEUTRAL (N) or with the
ignition off is dangerous. Your brakes will have
to do all the work of slowing down. 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 your engine running and your vehicle in
gear when you go downhill.
Know how to go uphill. You may want to shift down
to a lower gear. The lower gears help cool your
engine and transmission, and you can climb the
hill better.
Stay in your own lane when driving on two-lane
roads in hills or mountains. Do not swing wide
or cut across the center of the road. Drive at speeds
that let you stay in your own lane.
As you go over the top of a hill, be alert. There
could be something in your lane, like a stalled
car or an accident.
You may see highway signs on mountains that
warn of special problems. Examples are long
grades, passing or no-passing zones, a falling rocks
area or winding roads. Be alert to these and take
appropriate action.
4-51

Dinghy Towing
Use the following procedure to tow your vehicle:
1. Shift the transmission to PARK (P).
2. Turn the engine off, but leave the ignition on.
3. Firmly set the parking brake.
4. Securely attach the vehicle being towed to the
tow vehicle.
5. Shift the transfer case to NEUTRAL (N). See
All-Wheel Drive on page 2-25for the proper
procedure to select the NEUTRAL position for
your vehicle.
6. Release the parking brake only after the vehicle
being towed is rmly attached to the towing
vehicle. You can use your vehicle’s front mounted
receiver with the proper accessories to tow it.
See “Front Mounted Receiver” underIf You Are
Stuck: In Sand, Mud, Ice or Snow on page 4-56.
7. Turn the engine off and leave the steering column
unlocked.{CAUTION:
Shifting an all-wheel-drive vehicle’s transfer
case into NEUTRAL can cause your vehicle to
roll even if the transmission is in Park (P). You
or others could be injured. Make sure the
parking brake is rmly set before you shift the
transfer case to NEUTRAL.
Dolly Towing
Your vehicle can not be dolly towed. If you must tow
your vehicle behind another, use the dinghy towing
procedure listed previously.
Notice:Dolly towing your vehicle will damage
drivetrain components. Do not dolly tow your
vehicle.
4-66

Electronically Controlled Air
Suspension System
The electronically controlled air suspension, if equipped,
keeps the rear of your vehicle level as you load and
unload it. The system includes a compressor, two height
sensor and two air springs supporting the vehicle.
The engine must be running for the system to operate
and level the vehicle after loading or unloading. The
system will suspend leveling if any of the doors and/or
the liftgate are open. Once the doors are closed,
system leveling will continue.
You may hear the compressor running when you load
your vehicle, and periodically as the system adjusts
the vehicle to the standard ride height. You may
also hear the release of air similar to a hissing sound
during suspension operation. This is normal.
Load leveling will not function normally with the inator
hose attached to the inator outlet. Remove the
inater hose from the outlet when it is not in use. See
Accessory Inator on page 5-76.
Overload and Overheat Protection
Overload protection is designed to protect the air
suspension system and is an indication to the driver that
the vehicle is overloaded.
If the rear suspension remains at a low height, the rear
axle load has exceeded GAWR (Gross Axle Weight
Rating). When the overload protection mode is activated,
the compressor operates for about 30 seconds to one
minute without raising the vehicle depending on the
amount of overload. This will continue each time
the ignition is turned on until the rear axle load is
reduced below GAWR.
If the total rear GAWR (Gross Axle Weight Rating) is
reached, the suspension may be slightly less than level.
This is normal and does not mean there is a problem
with the air suspension.
If the system overheats, it will shut down and stop all
leveling functions until the system cools down.
During this time the SERVICE AIR SUSPENSION
message will appear in the DIC. SeeDriver Information
Center (DIC) on page 3-44for more information.
4-74

How to Reset the CHANGE ENGINE OIL
Message
The GM Oil Life System calculates when to change
your engine oil and lter based on vehicle use. Anytime
your oil is changed, reset the system so it can
calculate when the next oil change is required. If a
situation occurs where you change your oil prior to a
CHANGE ENGINE OIL message being turned on, reset
the system.
To reset the CHANGE ENGINE OIL message, see “GM
Oil Life System” underDIC Operation and Displays
on page 3-44for vehicles equipped with the DIC, or do
the following:
1. Turn the ignition key to RUN with the engine off.
2. Fully press and release the accelerator pedal slowly
three times within ve seconds.
If the OIL LIFE RESET message ashes for
10 seconds, the system is resetting.
3. Turn the key to LOCK.
If the CHANGE ENGINE OIL message comes back on
when you start your vehicle, the engine oil life system
has not reset. Repeat the procedure. If it still does
not reset, see your dealer for service.
What to Do with Used Oil
Used engine oil contains certain elements that may be
unhealthy for your skin and could even cause cancer.
Do not let used oil stay on your skin for very long. Clean
your skin and nails with soap and water, or a good
hand cleaner. Wash or properly dispose of clothing or
rags containing used engine oil. See the manufacturer’s
warnings about the use and disposal of oil products.
Used oil can be a threat to the environment. If you
change your own oil, be sure to drain all the oil from the
lter before disposal. Never dispose of oil by putting it in
the trash, pouring it on the ground, into sewers, or into
streams or bodies of water. Instead, recycle it by taking it
to a place that collects used oil. If you have a problem
properly disposing of your used oil, ask your dealer, a
service station or a local recycling center for help.
5-18

What to Use
To determine what kind of uid to use, see
Recommended Fluids and Lubricants on page 6-12.
Always use the proper uid. Failure to use the proper
uid can cause leaks and damage hoses and seals.
Windshield Washer Fluid
What to Use
When you need windshield washer uid, be sure to read
the manufacturer’s instructions before use. If you will
be operating your vehicle in an area where the
temperature may fall below freezing, use a uid that has
sufficient protection against freezing.
Adding Washer Fluid
Your vehicle has a low washer uid message that
comes on when the washer uid is low. The message is
displayed for 15 seconds at the start of each ignition
cycle if the uid is low. When the LOW WASHER FLUID
message is displayed, you will need to add washer
uid to the windshield washer uid reservoir.
The windshield washer
uid reservoir is located in
the engine compartment
on the passenger’s side of
the vehicle. SeeEngine
Compartment Overview on
page 5-12for reservoir
location.
5-37

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

Fuses Usage
GLOW PLUG Not Used
CUST FEED Gasoline Accessory Power
STUD #1Accessory Power/Trailer
Wiring
MBEC 1Mid Bussed Electrical Center
Power Feed, Front Seats,
Right Doors
BLOWER Front Climate Control Fan
LBEC 2Left Bussed Electrical Center,
Door Modules, Door Locks,
Auxiliary Power Outlet—Rear
Cargo Area and Instrument
Panel
STUD #2Accessory Power/Trailer
Wiring Brake Feed
ABS Anti-Lock Brakes
VSES/ECASElectronically Controlled Air
Suspension
IGN A Ignition Switch
IGN B Ignition SwitchFuses Usage
LBEC 1Left Bussed Electrical Center,
Left Doors, Truck Body
Controller, Flasher Module
TRL PARK Parking Lamps Trailer Wiring
RR PARKRight Rear Parking and
Sidemarker Lamps
LR PARKLeft Rear Parking and
Sidemarker Lamps
PARK LP Parking Lamps Relay
STARTER Starter Relay
INTPARK Roof Marker Lamps
STOP LP Stoplamps
TBC BATTTruck Body Controller Battery
Feed
SUNROOF Sunroof
SEO B2 Off-Road Lamps
4WS Vent Solenoid Canister
RR HVAC Not Used
AUX PWRAuxiliary Power Outlet —
Console
5-108

Fuses Usage
IGN 1 PCM Ignition
PCM 1 Powertrain Control Module
ETC/ECMElectronic Throttle Control,
Electronic Brake Controller
INJ 1Ignition Coil, Fuel
Injectors-Bank 1
INJ 2Ignition Coil, Fuel
Injectors-Bank 2
IGN EInstrument Panel Cluster, Air
Conditioning Relay, Turn
Signal/Hazard Switch, Starter
Relay, Electronic Brake
Controller TC2 Mode Switch
RTDElectronic Brake Controller
Battery Feed
TRL B/U Backup Lamps Trailer Wiring
PCM BPowertrain Control Module,
Fuel Pump
F/PMP Fuel Pump (Relay)
02A Oxygen Sensors
B/U LPBack-up Lamps, Automatic
Transmission Shift Lock
Control SystemFuses Usage
RR DEFOG Rear Window Defogger
HDLP-HI Headlamp High Beam Relay
PRIME Not Used
O2B Oxygen Sensors
SIRSupplemental Inatable
Restraint System
FRT PARKFront Parking Lamps,
Sidemarker Lamps
DRLDaytime Running Lamps
(Relay)
SEO IGN Rear Defog Relay
TBC IGN1 Truck Body Controller Ignition
HI HDLP-LT High Beam Headlamp-Left
LH HID Not Used
DRL Daytime Running Lamps
IPC/DICInstrument Panel
Cluster/Driver Information
Center
HVAC/ECASClimate Control
Controller/Electronically
Controlled Air Suspension
CIG LTR Cigarette Lighter
5-109

Automatic Transmission Shift Lock
Control System Check
{CAUTION:
When you are doing this inspection, the
vehicle could move suddenly. If the vehicle
moves, you or others could be injured.
1. Before you start, be sure you have enough room
around the vehicle. It should be parked on a level
surface.
2. Firmly apply the parking brake. SeeParking Brake
on page 2-29if necessary.
Be ready to apply the regular brake immediately if
the vehicle begins to move.
3. With the engine off, turn the key to the RUN
position, but do not start the engine. Without
applying the regular brake, try to move the shift
lever out of PARK (P) with normal effort. If the shift
lever moves out of PARK (P), contact your GM
Goodwrench dealer for service.
Ignition Transmission Lock Check
While parked, and with the parking brake set, try to turn
the ignition key to LOCK in each shift lever position.
The key should turn to LOCK only when the
shift lever is in PARK (P).
The key should come out only in LOCK.
Contact your GM Goodwrench dealer if service is
required.
Parking Brake and Automatic
Transmission Park (P) Mechanism Check
{CAUTION:
When you are doing this check, your vehicle
could begin to move. You or others could be
injured and property could be damaged. Make
sure there is room in front of your vehicle in
case it begins to roll. Be ready to apply the
regular brake at once should the vehicle begin
to move.
6-11