2008 HUMMER H3 ignition

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.
SeeDriving in Rain and on Wet Roads on page 4-33for
more information on driving through water.
After Off-Road Driving
Remove any brush or debris that has collected on
the underbody, chassis, or under the hood. These
accumulations can be a re hazard.
After operation in mud or sand, have the brake linings
cleaned and checked. These substances can cause
glazing and uneven braking. Check the engine and
oil coolers and underbody skid shields for mud
accumulation. Thoroughly and carefully clean these
devices to allow proper cooling. Check the bodystructure, steering, suspension, underbody shields,
wheels, tires, and exhaust system for damage. Also,
check the fuel lines and cooling system for any leakage.
Your vehicle will require more frequent service due
to off-road use. See the Maintenance Schedule
for additional information.
Assist Steps
If your vehicle has removable side steps, remove the
steps prior to off-roading to give your vehicle more ground
clearance and to prevent damage to the vehicle from the
side steps dragging and/or catching on obstacles.
Notice:Do not drive off-road with the side steps
attached to your vehicle. You can damage the
side steps and/or your vehicle’s frame if they get
caught or drag against an obstacle. This damage
would not be covered by your vehicle’s warranty.
Always remove the side steps prior to any off-road
driving.
4-31

{CAUTION:
If you do not shift down, the brakes 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. Shift down
to let the engine assist the brakes on a steep
downhill slope.
{CAUTION:
Coasting downhill in NEUTRAL (N) or with the
ignition off is dangerous. The brakes will have
to do all the work of slowing down and 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 the engine running and your
vehicle in gear when you go downhill.
Stay in your own lane. Do not swing wide or cut
across the center of the road. Drive at speeds
that let you stay in your own lane.
Top of hills: Be alert — something could be in your
lane (stalled car, accident).
Pay attention to special road signs (falling rocks
area, winding roads, long grades, passing or
no-passing zones) and take appropriate action.
SeeOff-Road Driving on page 4-12for information
about driving off-road.
Winter Driving
Here are some tips for winter driving:
Have your vehicle in good shape for winter.
You might want to put winter emergency supplies in
your vehicle.
Include an ice scraper, a small brush or broom,
a supply of windshield washer uid, a rag, some
winter outer clothing, a small shovel, a ashlight, a
red cloth, and a couple of reective warning triangles.
And, if you will be driving under severe conditions,
include a small bag of sand, a piece of old carpet,
or a couple of burlap bags to help provide traction.
Be sure you properly secure these items in your vehicle.
Also seeTires on page 5-54.
4-35

Dinghy Towing
Use the following procedure to tow your vehicle:
1. Shift the transmission to NEUTRAL (N).
2. Turn the engine off, but leave the ignition in ON.
3. Firmly set the parking brake.
4. Securely attach the vehicle being towed to the tow
vehicle.
{CAUTION:
Shifting a full-time four-wheel-drive vehicle’s
transfer case into NEUTRAL can cause
your vehicle to roll even if the automatic
transmission is in PARK (P) or the manual
transmission is in any gear. You or others
could be injured. Make sure the parking brake
is rmly set before you shift the transfer case
to NEUTRAL.
5. Shift the transfer case to NEUTRAL (N). See
Full-Time Four-Wheel Drive on page 2-27for
the proper procedure to select the NEUTRAL
position for your vehicle.6. Put the transmission in PARK (P) for an
automatic transmission or in FIRST (1) for
a manual transmission.
7. Release the parking brake only after the vehicle
being towed is rmly attached to the towing
vehicle.
8. Turn the ignition off.
After towing, see “Shifting Out of NEUTRAL” under
Full-Time Four-Wheel Drive on page 2-27.
Dolly Towing
Notice:Dolly towing your vehicle will damage
drivetrain components. Do not dolly tow your
vehicle.
Your vehicle cannot be dolly towed. If you must tow
your vehicle behind another, use the dinghy towing
procedure listed previously.
4-49

How to Reset the Engine Oil Life
System
The Engine Oil Life System calculates when to change
the engine oil and lter based on vehicle use. Whenever
the oil is changed, reset the system so it can calculate
when the next oil change is required. If a situation occurs
where you change the oil prior to a CHANGE OIL
message being turned on, reset the system.
To reset the Engine Oil Life system:
1. With the engine off, turn the ignition to ON/RUN.
2. Press and release the stem in the lower center
of the instrument cluster until the OIL LIFE
message is displayed.
3. Once the alternating OIL LIFE and RESET
messages appear, press and hold the stem
until several beeps sound. This conrms that the oil
life system has been reset.
4. Turn the key to LOCK/OFF.
If the CHANGE OIL message comes back on when you
start your vehicle, the engine oil life system has not
reset. Repeat the procedure. SeeDIC Warnings
and Messages on page 3-43.
What to Do with Used Oil
Used engine oil contains certain elements that can 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 used oil, ask your
dealer/retailer, a service station, or a local recycling
center for help.
5-19

Jump Starting
If your vehicle’s battery has run down, you may want to
use another vehicle and some jumper cables to start your
vehicle. Be sure to use the following steps to do it safely.
{CAUTION:
Batteries can hurt you. They can be dangerous
because:
They contain acid that can burn you.
They contain gas that can explode or
ignite.
They contain enough electricity to
burn you.
If you do not follow these steps exactly, some
or all of these things can hurt you.
Notice:Ignoring these steps could result in costly
damage to your vehicle that would not be covered
by your warranty.
Trying to start your vehicle by pushing or pulling it
will not work, and it could damage your vehicle.
1. Check the other vehicle. It must have a 12-volt
battery with a negative ground system.Notice:If the other vehicle’s system is not a 12-volt
system with a negative ground, both vehicles can
be damaged. Only use vehicles with 12-volt systems
with negative grounds to jump start your vehicle.
2. Get the vehicles close enough so the jumper cables
can reach, but be sure the vehicles are not touching
each other. If they are, it could cause a ground
connection you do not want. You would not 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.
If you have a four-wheel-drive vehicle, be sure the
transfer case is not in NEUTRAL.
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 the accessory power outlets. Turn off
the radio and all lamps that are not needed. This
will avoid sparks and help save both batteries. And
it could save the radio!
5-42

Tire Pressure Monitor Operation
The Tire Pressure Monitor System (TPMS) is designed
to warn the driver when a low tire pressure condition
exists. TPMS sensors are mounted onto each tire
and wheel assembly on your vehicle, excluding the
spare tire. The TPMS sensors monitor the air pressure
in your vehicle’s tires and transmit the tire pressure
readings to a receiver located in the vehicle.
When a low tire pressure
condition is detected, the
TPMS illuminates the
low tire pressure warning
light located on the
instrument panel cluster.
At the same time, a Driver Information Center (DIC)
message is displayed on the DIC display screen. The
low tire pressure warning light and the DIC warning
message come on at each ignition cycle until the tires
are inated to the correct ination pressure.For additional information and details about the DIC
operation and displays seeDIC Operation and Displays
on page 3-40andDIC Warnings and Messages on
page 3-43.
The low tire pressure warning light may come on in cool
weather when the vehicle is rst started, and then
turn off as you start to drive. This could be an early
indicator that the air pressure in the tire(s) are getting
low and need to be inated to the proper pressure.
A Tire and Loading Information label, attached to your
vehicle, shows the size of your vehicle’s original
equipment tires and the correct ination pressure for
your vehicle’s tires when they are cold. SeeLoading
Your Vehicle on page 4-42, for an example of the Tire
and Loading Information label and its location on
your vehicle. Also seeInflation - Tire Pressure on
page 5-62.
Your vehicle’s TPMS can warn you about a low tire
pressure condition but it does not replace normal
tire maintenance. SeeTire Inspection and Rotation on
page 5-68andTires on page 5-54.
Notice:Liquid tire sealants could damage the Tire
Pressure Monitor System (TPMS) sensors. Sensor
damage caused by using a tire sealant is not
covered by your warranty. Do not use liquid tire
sealants.
5-65

TPMS Malfunction Light and Message
The TPMS will not function properly if one or more of the
TPMS sensors are missing or inoperable. When the
system detects a malfunction, the low tire warning light
ashes for about one minute and then stays on for
the remainder of the ignition cycle. A DIC warning
message is also displayed. The low tire warning light
and DIC warning message come on at each ignition
cycle until the problem is corrected. Some of the
conditions that can cause the malfunction light and DIC
message to come on are:
One of the road tires has been replaced with the
spare tire. The spare tire does not have a TPMS
sensor. The TPMS malfunction light and DIC
message should go off once you re-install the road
tire containing the TPMS sensor.
The TPMS sensor matching process was started
but not completed or not completed successfully
after rotating the vehicle’s tires. The DIC message
and TPMS malfunction light should go off once
the TPMS sensor matching process is performed
successfully. See “TPMS Sensor Matching Process”
later in this section.
One or more TPMS sensors are missing or
damaged. The DIC message and the TPMS
malfunction light should go off when the TPMS
sensors are installed and the sensor matching
process is performed successfully. See your
dealer/retailer for service.
Replacement tires or wheels do not match your
vehicle’s original equipment tires or wheels.
Tires and wheels other than those recommended
for your vehicle could prevent the TPMS from
functioning properly. SeeBuying New Tires on
page 5-71.
Operating electronic devices or being near facilities
using radio wave frequencies similar to the TPMS
could cause the TPMS sensors to malfunction.
If the TPMS is not functioning it cannot detect or signal
a low tire condition. See your dealer/retailer for
service if the TPMS malfunction light and DIC message
comes on and stays on.
5-66

TPMS Sensor Matching Process
Each TPMS sensor has a unique identication code.
Any time you replace one or more of the TPMS sensors
or rotate your vehicle’s tires, the identication codes
need to be matched to the new tire/wheel position.
The sensors are matched to the tire/wheel positions in
the following order: driver side front tire, passenger
side front tire, passenger side rear tire, and driver side
rear tire using a TPMS diagnostic tool. See your
dealer/retailer for service.
The TPMS sensors can also be matched to each
tire/wheel position by increasing or decreasing the tire’s
air pressure. If increasing the tire’s air pressure, do
not exceed the maximum ination pressure indicated on
the tire’s sidewall. To let air-pressure out of a tire you
can use the pointed end of the valve cap, a pencil-style
air pressure gage, or a key.
You have one minute to match the rst tire/wheel
position, and ve minutes overall, to match all four
tire/wheel positions. If it takes longer than one minute,
to match the rst tire and wheel, or more than
ve minutes to match all four tire and wheel positions,
the matching process stops and you need to start over.The TPMS sensor matching procedure is outlined
below:
1. Set the parking brake.
2. Turn the ignition switch to ON/RUN with the
engine off.
3. Turn the exterior lamp switch from AUTO to OFF
four times within three seconds. A double horn
chirp will sound and the TPMS low tire warning light
starts ashing. The double horn chirp and ashing
TPMS warning light indicates the TPMS matching
process has started. The TPMS warning light
should continue ashing throughout the matching
procedure. The LOW TIRE message displays on the
Driver Information Center (DIC).
4. Start with the driver side front tire.
5. Remove the valve cap from the valve cap stem.
Activate the TPMS sensor by increasing or
decreasing the tire’s air pressure for 10 seconds,
then stop and listen for a single horn chirp.
The single horn chirp should sound within
15 seconds, conrming that the sensor identication
code has been matched to this tire and wheel
position. If you do not hear the conrming single
horn chirp, turn the ignition switch to LOCK and start
over beginning with Step 2.
5-67