2004 GMC ENVOY XL engine

6(Floor):This mode directs most of the air to the
oor outlets. Some air also comes out of the defroster
and side window outlets. The recirculation button cannot
be selected in oor mode.
h(Recirculation):Press this button to turn
recirculation mode on or off. When this button is
pressed, an indicator light in the button will also come
on to let you know that it is activated. Recirculation
mode is used to recirculate the air inside of your vehicle.
Use this mode to help prevent outside odors and/or
dust from entering your vehicle or to help cool the air
inside of your vehicle more quickly. Recirculation
mode can be used with vent and bi-level modes, but it
cannot be used with oor, defog or defrost modes.
If the weather is cold and damp, the system may cause
the windows to fog while using recirculation mode. If the
windows do start to fog, select defog or defrost mode.
#A/C (Air Conditioning):Press this button to
manually turn the air conditioning system on or off.
When the system is on, the system will automatically
begin to cool and dehumidify the air inside of your
vehicle.
If you select air conditioning off while in front defrost or
defog mode, the air conditioning off symbol will ash
to let you know this option is not allowed.
You may notice a slight change in engine performance
when the air-conditioning compressor shuts off and
turns on again. This is normal.
A/C OFF (Air Conditioning Off):When you turn the
air conditioning off, the words A/C OFF will appear
on the display. When the air conditioning is selected or
in AUTO mode, the system will run the air conditioning
automatically.
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Warning Lights, Gages, and
Indicators
This part describes the warning lights and gages that
may be on your vehicle. The pictures will help you
locate them.
Warning lights and gages can signal that something is
wrong before it becomes serious enough to cause
an expensive repair or replacement. Paying attention
to your warning lights and gages could also save you
or others from injury.
Warning lights come on when there may be or is a
problem with one of your vehicle’s functions. As you
will see in the details on the next few pages, some
warning lights come on briey when you start the engine
just to let you know they’re working. If you are familiar
with this section, you should not be alarmed when
this happens.Gages can indicate when there may be or is a problem
with one of your vehicle’s functions. Often gages
and warning lights work together to let you know when
there’s a problem with your vehicle.
When one of the warning lights comes on and stays on
when you are driving, or when one of the gages
shows there may be a problem, check the section that
tells you what to do about it. Please follow this
manual’s advice.
Waiting to do repairs can be costly–and even
dangerous. So please get to know your warning lights
and gages. They’re a big help.
Your vehicle may also have a Driver Information Center
(DIC) that works along with the warning lights and
gages. SeeDriver Information Center (DIC) on
page 3-51.
3-35

Speedometer and Odometer
Your speedometer lets you see your speed in both
miles per hour (mph) and kilometers per hour (km/h).
Your odometer shows how far your vehicle has
been driven, in either miles (used in the United States)
or kilometers (used in Canada).
The odometer mileage can be checked without the
vehicle running. Simply press the trip stem located on
the instrument panel cluster.
You may wonder what happens if your vehicle needs a
new odometer installed. The new one will be set to
the correct mileage total of the old odometer.
Trip Odometer
The trip odometer can tell you how far your vehicle has
been driven since you last set the trip odometer to zero.
The trip odometer is part of the Driver Information
Center (DIC). For vehicles without a DIC, press the stem
located on the instrument panel cluster to display the
trip odometer. Press and hold the stem to reset the trip
odometer once it is displayed.
Tachometer
The tachometer displays the engine speed in revolutions
per minute (rpm).
3-37

{CAUTION:
If the air bag readiness light stays on after you
start your vehicle, it means the air bag system
may not be working properly. The air bags in
your vehicle may not inate in a crash, or they
could even inate without a crash. To help
avoid injury to yourself or others, have your
vehicle serviced right away if the air bag
readiness light stays on after you start your
vehicle.
The air bag readiness light should ash for a few
seconds when you turn the ignition key to RUN.
If the light doesn’t come on then, have it xed so it
will be ready to warn you if there is a problem.
Charging System Light
The charging system light
will come on briey when
you turn on the ignition,
but the engine is not
running, as a check to
show you it is working.
It should go out once the engine is running. If it stays
on, or comes on while you are driving, you may have
a problem with the charging system. It could indicate
that you have problems with a generator drive belt,
or another electrical problem. Have it checked
right away. Driving while this light is on could drain
your battery.
If you must drive a short distance with the light on,
be certain to turn off all your accessories, such as the
radio and air conditioner.
3-39

Voltmeter Gage
When your engine is not
running, but the ignition is
on (in RUN), this gage
shows your battery’s state
of charge in DC volts.
When the engine is running, the gage shows the
condition of the charging system. Readings between
the low and high warning zones indicate the normal
operating range.
Readings in the low warning zone may occur when a
large number of electrical accessories are operating in
the vehicle and the engine is left idling for an extended
period. This condition is normal since the charging
system is not able to provide full power at engine idle.As engine speeds are increased, this condition should
correct itself as higher engine speeds allow the charging
system to create maximum power.
You can only drive for a short time with the reading in
either warning zone. If you must drive, turn off all
unnecessary accessories.
Readings in either warning zone indicate a possible
problem in the electrical system. Have the vehicle
serviced as soon as possible.
Brake System Warning Light
When the ignition is on, the brake system warning light
will come on when you set your parking brake. The
light will stay on if your parking brake doesn’t release
fully. If it stays on after your parking brake is fully
released, it means you have a brake problem. A chime
may also sound when the light comes on.
Your vehicle’s hydraulic brake system is divided into
two parts. If one part isn’t working, the other part can still
work and stop you. For good braking, though, you
need both parts working well.
3-40

Anti-Lock Brake System Warning
Light
With the anti-lock brake
system, this light will come
on when you start your
engine and may stay on
for several seconds.
That’s normal. A chime
may also sound when
the light comes on.
If the light stays on, or comes on when you’re driving,
your vehicle needs service. If the regular brake
system warning light isn’t on, you still have brakes, but
you don’t have anti-lock brakes. If the regular brake
system warning light is also on, you don’t have anti-lock
brakes and there’s a problem with your regular
brakes. SeeBrake System Warning Light on page 3-40
earlier in this section.
The anti-lock brake system warning light should come
on briey when you turn the ignition key to RUN.
If the light doesn’t come on then, have it xed so it will
be ready to warn you if there is a problem.
Engine Coolant Temperature Gage
This gage shows the engine coolant temperature.
If the gage pointer moves into the red area, it means
that your engine coolant has overheated. If you
have been operating your vehicle under normal driving
conditions, you should pull off the road, stop your
vehicle and turn off the engine as soon as possible.
SeeEngine Overheating on page 5-28for more
information.
United StatesCanada
3-42

Malfunction Indicator Lamp
Service Engine Soon Light in the
United States or Check Engine Light
in Canada
Your vehicle is equipped with a computer which
monitors operation of the fuel, ignition, and emission
control systems.
This system is called OBD II (On-Board
Diagnostics-Second Generation) and is intended to
assure that emissions are at acceptable levels for the life
of the vehicle, helping to produce a cleaner environment.The SERVICE ENGINE SOON or CHECK ENGINE light
comes on to indicate that there is a problem and service
is required. Malfunctions often will be indicated by the
system before any problem is apparent. This may prevent
more serious damage to your vehicle. This system is also
designed to assist your service technician in correctly
diagnosing any malfunction.
Notice:If you keep driving your vehicle with this
light on, after a while, your emission controls may
not work as well, your fuel economy may not be as
good, and your engine may not run as smoothly.
This could lead to costly repairs that may not be
covered by your warranty.
Notice:Modications made to the engine,
transmission, exhaust, intake, or fuel system of
your vehicle or the replacement of the original tires
with other than those of the same Tire Performance
Criteria (TPC) can affect your vehicle’s emission
controls and may cause this light to come on.
Modications to these systems could lead to costly
repairs not covered by your warranty. This may
also result in a failure to pass a required Emission
Inspection/Maintenance test. United States
Canada
3-43

This light should come on, as a check to show you
it is working, when the ignition is on and the engine
is not running. If the light does not come on, have
it repaired. This light will also come on during a
malfunction in one of two ways:
Light Flashing— A misre condition has been
detected. A misre increases vehicle emissions
and may damage the emission control system
on your vehicle. Diagnosis and service may
be required.
Light On Steady— An emission control system
malfunction has been detected on your vehicle.
Diagnosis and service may be required.
If the Light Is Flashing
The following may prevent more serious damage to
your vehicle:
Reducing vehicle speed
Avoiding hard accelerations
Avoiding steep uphill grades
If you are towing a trailer, reduce the amount
of cargo being hauled as soon as it is possible
If the light stops ashing and remains on steady,
see “If the Light Is On Steady” following.If the light continues to ash, when it is safe to do so,
stop the vehicle. Find a safe place to park your vehicle.
Turn the key off, wait at least 10 seconds and restart
the engine. If the light remains on steady, see “If
the Light Is On Steady” following. If the light is still
ashing, follow the previous steps, and see your dealer
for service as soon as possible.
If the Light Is On Steady
You may be able to correct the emission system
malfunction by considering the following:
Did you recently put fuel into your vehicle?
If so, reinstall the fuel cap, making sure to fully install
the cap. SeeFilling Your Tank on page 5-7. The
diagnostic system can determine if the fuel cap has
been left off or improperly installed. A loose or missing
fuel cap will allow fuel to evaporate into the atmosphere.
A few driving trips with the cap properly installed
should turn the light off.
Did you just drive through a deep puddle of water?
If so, your electrical system may be wet. The condition
will usually be corrected when the electrical system
dries out. A few driving trips should turn the light off.
3-44