2008 HUMMER H3 check engine light

Emissions Inspection and Maintenance
Programs
Some state/provincial and local governments have or
might begin programs to inspect the emission control
equipment on your vehicle. Failure to pass this
inspection could prevent you from getting a vehicle
registration.
Here are some things you need to know to help your
vehicle pass an inspection:
Your vehicle will not pass this inspection if the check
engine light is on or not working properly.
Your vehicle will not pass this inspection if the OBD
(on-board diagnostic) system determines that critical
emission control systems have not been completely
diagnosed by the system. The vehicle would be
considered not ready for inspection. This can happen if
you have recently replaced the battery or if the
battery has run down. The diagnostic system is
designed to evaluate critical emission control systems
during normal driving. This can take several days
of routine driving. If you have done this and your vehicle
still does not pass the inspection for lack of OBD
system readiness, your dealer/retailer can prepare the
vehicle for inspection.
Oil Pressure Light
{CAUTION:
Do not keep driving if the oil pressure is low. If
you do, your engine can become so hot that it
catches re. You or others could be burned.
Check your oil as soon as possible and have
your vehicle serviced.
Notice:Lack of proper engine oil maintenance may
damage the engine. The repairs would not be covered
by your warranty. Always follow the maintenance
schedule in this manual for changing engine oil.
This light will come on
briey when you start your
engine. If it does not,
have your vehicle serviced.
When the light comes on and stays on, it means that oil
is not owing through your engine properly. You
could be low on oil and you might have some other
system problem.
3-38

AC (Air Conditioning) OFF
This message displays when the engine coolant
temperature is too high and the air conditioning in your
vehicle needs to be turned off. SeeEngine Overheating
on page 5-29andClimate Control System on
page 3-22for more information. This message displays
along with the ENG HOT message.
ABS (Antilock Brake System) FAULT
This message displays if there is a problem with
the Antilock Brake System (ABS). Check the ABS as
soon as possible and have your vehicle serviced by your
dealer/retailer. SeeBrakes on page 5-38andAntilock
Brake System Warning Light on page 3-34for more
information. Press and release the reset stem to
acknowledge the message and clear it from the display.
BRAKES
This message displays if there is a problem with the
brakes. Check the brakes as soon as possible and have
your vehicle serviced by your dealer/retailer. See
Brakes on page 5-38andBrake System Warning Light
on page 3-33for more information. Press and release
the reset stem to acknowledge the message and clear it
from the display.
CHANGE OIL
This message displays when the oil needs to be
changed. Check the oil in your vehicle as soon as
possible and have your vehicle serviced by your
dealer/retailer. SeeEngine Oil on page 5-15and
Scheduled Maintenance on page 6-4for more
information. Press and release the reset stem to
acknowledge the message and clear it from the display.
DOORS
This message displays when one or more of the doors
is ajar. Check all the doors on your vehicle to make
sure they are closed. The message clears from
the display after all of the doors are closed.
ENG (Engine) HOT
This message displays when the engine coolant
temperature is hot. Check the engine coolant
temperature gage. SeeEngine Coolant Temperature
Gage on page 3-35. Have your vehicle serviced by your
dealer/retailer as soon as possible if you suspect the
engine is overheating. SeeEngine Overheating on
page 5-29for more information.
3-44

FLUID
This message displays if the brake uid is low. Check
the brake uid as soon as possible and have your
vehicle serviced by your dealer/retailer. SeeBrakes on
page 5-38for more information. Press and release
the reset stem to acknowledge the message and clear it
from the display.
FUEL CAP
This message displays if the vehicle’s fuel cap is either
off or loose. Pull over as soon as possible and check
to see if the fuel cap is secure. You may also see
the check engine light on the instrument panel cluster.
If the check engine light does come on when the
fuel cap was loose, it may take a few driving trips before
the light turns off. SeeMalfunction Indicator Lamp on
page 3-36for more information if the light still remains
on. Press and release the reset stem to acknowledge
the message and clear it from the display.
LOW FUEL
This message displays if the level of fuel in the vehicle
is low. Also check the fuel gage. SeeFuel Gage on
page 3-40for more information. Rell the fuel tank as
soon as possible.
LOW TIRE
This message displays if a low tire pressure is detected
in any of the vehicle’s tires. Press and release the reset
stem to acknowledge the message and clear it from the
display. The message appears at each ignition cycle until
the tires are inated to the correct ination pressure. See
Tires on page 5-54andInflation - Tire Pressure on
page 5-62for more information on tires and the correct
ination pressures.
OIL
This message displays when the oil pressure is low.
SeeOil Pressure Light on page 3-38andEngine Oil
on page 5-15for more information.
PARK BRK (Brake)
This message displays when the parking brake is set.
SeeParking Brake on page 2-32andBrake System
Warning Light on page 3-33for more information. The
message clears from the display after the parking brake
is released or by pressing and releasing the reset stem.
3-45

REDUCED POWER
This message 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/retailer for service as soon as possible.
Press and release the reset stem to acknowledge the
message and clear it from the display.
SERV (Service) 4WD (Four-Wheel
Drive)
This message displays when there is a problem with the
transfer case control system. Check the transfer case
on your vehicle and have it serviced by your
dealer/retailer. SeeFull-Time Four-Wheel Drive on
page 2-27for more information about the transfer case.
Press and release the reset stem to acknowledge
the message and clear it from the display.
SERV (Service) TPM (Tire Pressure
Monitor)
This message displays if a part on the Tire Pressure
Monitor System (TPMS) is not working properly. The tire
pressure light also ashes and then remains on during
the same ignition cycle. SeeTire Pressure Light on
page 3-35. Several conditions may cause this message
to appear. SeeTire Pressure Monitor Operation on
page 5-65for more information. If the warning comes on
and stays on, there may be a problem with the TPMS.
See your dealer/retailer.
SERV (Service) VEH (Vehicle)
This message displays if your vehicle needs service.
Have your vehicle serviced by your dealer/retailer
as soon as possible.
3-46

This is a mistake. The brakes might not have time to
cool between hard stops. The brakes will wear out
much faster if you do a lot of heavy braking. If you
keep pace with the traffic and allow realistic following
distances, you will eliminate a lot of unnecessary
braking. That means better braking and longer
brake life.
If your vehicle ever loses electrical power while you
are driving, brake normally but do not pump the brakes.
If you do, the pedal could get harder to push down.
If your vehicle loses electrical power, you will still have
some power brake assist. But you will use it when
you brake. Once the power assist is used up, it can take
longer to stop, the brake pedal will be harder to push,
and you might experience longer pedal travel.
Adding non-dealer/non-retailer accessories can affect
your vehicle’s performance. SeeAccessories and
Modifications on page 5-3.Antilock Brake System (ABS)
Your vehicle has the Antilock Brake System (ABS),
an advanced electronic braking system that will
help prevent a braking skid.
When you start the engine and begin to drive away,
ABS will check itself. You might hear a momentary
motor or clicking noise while this test is going on.
This is normal.
If there is a problem with
ABS, this warning light will
stay on. SeeAntilock
Brake System Warning
Light on page 3-34.
Let us say the road is wet and you are driving safely.
Suddenly, an animal jumps out in front of you. You slam
on the brakes and continue braking. Here is what
happens with ABS:
A computer senses that wheels are slowing down.
If one of the wheels is about to stop rolling, the computer
will separately work the brakes at each wheel.
4-4

You can run the engine to keep warm, but be careful.
{CAUTION:
Snow can trap exhaust gases under your
vehicle. This can cause deadly CO (carbon
monoxide) gas to get inside. CO could
overcome you and kill you. You cannot see it
or smell it, so you might not know it is in your
vehicle. Clear away snow from around the
base of your vehicle, especially any that is
blocking the exhaust pipe. And check around
again from time to time to be sure snow does
not collect there.
Open a window just a little on the side of the
vehicle that is away from the wind. This will
help keep CO out.
Run your engine only as long as you must. This saves
fuel. When you run the engine, make it go a little faster
than just idle. That is, push the accelerator slightly. This
uses less fuel for the heat that you get and it keeps the
battery charged. You will need a well-charged battery to
restart the vehicle, and possibly for signaling later on with
the headlamps. Let the heater run for a while.
4-38

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, 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
Light-Duty Trailer Wiring Package
If your vehicle is not equipped with a trailer towing
package, the chassis harness will contain the following
blunt cut circuits:
Yellow: Left Stop/Turn Signal
Dark Green: Right Stop/Turn Signal
White: Ground
Brown: Tail Lamps
If you want to add on a trailer tow, it should be installed
by your dealer/retailer or a qualied service center.
Also, seeAdd-On Electrical Equipment on page 5-101
for more information.
4-59

How to Check and Add Fluid
The proper uid should be added if the level does not
reach the bottom of the diaphragm when it is in place in
the reservoir. See the instructions on the reservoir cap.
Engine Coolant
The cooling system in your vehicle is lled with
DEX-COOL®engine coolant. This coolant is designed
to remain in your vehicle for ve years or 150,000 miles
(240 000 km), whichever occurs rst, if you add only
DEX-COOL
®extended life coolant.
The following explains your cooling system and how to
add coolant when it is low. If you have a problem
with engine overheating, seeEngine Overheating on
page 5-29.A 50/50 mixture of clean, drinkable water and
DEX-COOL
®coolant will:
Give freezing protection down to−34°F (−37°C).
Give boiling protection up to 265°F (129°C).
Protect against rust and corrosion.
Help keep the proper engine temperature.
Let the warning lights and gages work as they
should.
Notice:Using coolant other than DEX-COOL
®may
cause premature engine, heater core, or radiator
corrosion. In addition, the engine coolant may
require changing sooner, at the rst maintenance
service after each 30,000 miles (50 000 km) or
24 months, whichever occurs rst. Any repairs
would not be covered by your warranty. Always use
DEX-COOL
®(silicate-free) coolant in your vehicle.
5-27