2007 GMC ENVOY DENALI Owners Manual

Tire Pressure Light
This light will come on
briey when you turn
the ignition to RUN.
This light will also come on when one or more of
your tires are signicantly underinated.If your vehicle has a Driver Information
Center (DIC), a CHECK TIRE PRESSURE DIC
message will accompany the light, seeDIC
Warnings and Messages on page 222
Stop and check your tires as soon as it is safe to
do so. If underinated, inate to the proper
pressure. SeeTires on page 439for more
information.
This light will ash for approximately 70 seconds
and then turn on solid if a problem is detected with
the Tire Pressure Monitor system.
SeeTire Pressure Monitor System on page 448
for more information.
209

Malfunction Indicator Lamp
Check Engine Light
Your vehicle has 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 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 awhile, 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. SeeAccessories
and Modifications on page 380.
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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 possibleIf 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 the Tank on page 385.
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.
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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.
Have you recently changed brands of fuel?
If so, be sure to fuel your vehicle with quality fuel.
SeeGasoline Octane on page 382. Poor fuel
quality will cause your engine not to run as
efficiently as designed. You may notice this as
stalling after start-up, stalling when you put
the vehicle into gear, misring, hesitation on
acceleration, or stumbling on acceleration. (These
conditions may go away once the engine is
warmed up.) This will be detected by the system
and cause the light to turn on.
If you experience one or more of these conditions,
change the fuel brand you use. It will require at
least one full tank of the proper fuel to turn the
light off.
If none of the above steps have made the light
turn off, your dealer can check the vehicle.
Your dealer has the proper test equipment and
diagnostic tools to x any mechanical or electrical
problems that may have developed.Emissions Inspection and
Maintenance Programs
Some state/provincial and local governments have
or may 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 your battery or if your battery has
run down. The diagnostic system is designed to
evaluate critical emission control systems
during normal driving. This may 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
can prepare the vehicle for inspection.
212

Oil Pressure Gage
The oil pressure gage shows the engine oil
pressure in psi (pounds per square inch) when the
engine is running. Canadian vehicles indicate
pressure in kPa (kilopascals).
{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.
Oil pressure may vary with engine speed, outside
temperature and oil viscosity, but readings
above the low pressure zone indicate the normal
operating range.
A reading in the low pressure zone may be
caused by a dangerously low oil level or other
problems causing low oil pressure.
United StatesCanada
213

Change Engine Oil Light
Your vehicle may
have a change
engine oil light.
When this light comes on it means that an oil
change and other maintenance procedures
are required for your vehicle.
SeeScheduled Maintenance on page 507and
Engine Oil on page 394for more information.
Once the engine oil has been changed, the change
engine oil light must be reset. Until it is reset,
the light will stay on when the engine is on.
Security Light
This light will come on
briey when you turn
the key toward START.
The light will stay on until the engine starts. If the
light ashes, the Passlock
®system has entered
a tamper mode. If the vehicle fails to start,
seePasslock
®on page 111.
If the light comes on continuously while driving
and stays on, there may be a problem with
the Passlock
®system. Your vehicle will not be
protected by Passlock®, and you should see
your dealer.
Also, seeContent Theft-Deterrent on page 110for
additional information regarding the security light.
214

Cruise Control Light
If your vehicle has a
Driver Information
Center (DIC), this light
will come on when
the cruise control is set.
SeeCruise Control on page 176andDIC Warnings
and Messages on page 222for more information.
Reduced Engine Power Light
This light comes on
when a noticeable
reduction in the
vehicle’s performance
occurs.The vehicle can be driven at a reduced speed
when the reduced engine power light is on,
but acceleration and speed may be reduced.
The performance may be reduced until the next
time you drive your vehicle. If this light stays
on, see your dealer as soon as possible for
diagnosis and repair.
This light may also come on if there is a problem
with the Electronic Throttle Control (ETC)
system. If this happens, take the vehicle in for
service as soon as possible.
Highbeam On Light
This light comes on
when the high-beam
headlamps are in use.
SeeHeadlamp High/Low-Beam Changer on
page 173.
215

Service Four-Wheel Drive
Warning Light
This light should come
on briey when you turn
on the ignition, as a
check to show you
it is working.
The service four-wheel drive light comes on to
indicate that there may be a problem with the drive
system and service is required. Malfunctions
can be indicated by the system before any problem
is apparent, which may prevent serious damage
to the vehicle. This system is also designed
to assist your dealer in correctly diagnosing a
malfunction.
Check Gages Warning Light
The check gages light
will come on briey
when you are starting
the engine.
If the light comes on and stays on while you are
driving, check your coolant temperature and
engine oil pressure gages to see if they are in the
warning zones.
Gate Ajar Light
If this light comes on,
the liftgate or liftglass is
not completely shut.
Close the liftgate or liftglass. Never drive with the
liftgate or liftglass even partially open.
216