1999 GMC ENVOY service indicator

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2-23
AUTO 4WD: This setting is ideal for use when road
conditions are variable. When driving your vehicle in
AUTO 4WD, the front axle is engaged, but the vehicle's
power is sent to the rear wheels. When the vehicle
senses a loss of traction, the system will automatically
engage four
-wheel drive. Driving in this mode results in
slightly lower fuel economy than 2HI.
4HI: Use 4HI when you need extra traction, such as
on snowy or icy roads or in most off
-road situations.
This setting also engages your front axle to help drive
your vehicle.
4LO: This setting also engages your front axle and
delivers extra torque. You may never need 4LO. It sends
maximum power to all four wheels. You might choose
4LO if you are driving off
-road in deep sand, deep mud,
and climbing or descending steep hills.
NEUTRAL: Shift the vehicle's transfer case to
NEUTRAL only when towing your vehicle. See
ªRecreational Vehicle Towingº or ªTowing Your
Vehicleº in the Index for more information.
CAUTION:
Shifting the transfer case to NEUTRAL can
cause your vehicle to roll even if the transmission
is in PARK (P). You or someone else could be
seriously injured. Be sure to set the parking
brake before placing the transfer case in
NEUTRAL. See ªParking Brakeº in the Index.
Indicator lights in the switches show which setting you
are in. The indicator lights will come on briefly when
you turn on the ignition and one will stay on. If the
lights do not come on, you should take your vehicle to
your dealer for service. An indicator light will flash
while shifting the transfer case. It will remain
illuminated when the shift is complete. If for some
reason the transfer case cannot make a requested shift, it
will return to the last chosen setting.
If the SERVICE 4WD light stays on, you should take
your vehicle to your dealer for service. See ªService
4WDº in the Index for further information.
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2-59
Full-Size Console
This device complies with Part 15 of the FCC Rules.
Operation is subject to the following two conditions:
(1) this device may not cause harmful interference, and (2)
this device must accept any interference received,
including interference that may cause undesired operation.
This device complies with RSS
-210 of Industry Canada.
Operation is subject to the following two conditions:
(1) this device may not cause interference, and (2) this
device must accept any interference, including
interference that may cause undesired operation
of the device.
Changes and modifications to this system by other than
an authorized service facility could void authorization to
use this equipment.
Programming the Transmitter
Do not use the universal transmitter with any garage
door opener that does not have the ªstop and reverseº
feature. This includes any garage door opener model
manufactured before April 1, 1982.
Be sure that people and objects are clear of the garage
door you are programming.
Your vehicle's engine should be turned off while
programming the transmitter. Follow these steps to
program up to three channels:
1. If you have previously programmed a transmitter
channel, proceed to Step 2. Otherwise, hold down
the two outside buttons on the universal transmitter
until the indicator light begins to flash rapidly (after
20 seconds). Then release the buttons. This
procedure initializes the memory and erases any
previous settings for all three channels.
2. Decide which one of the three channels you want to
program. Hold the end of the hand
-held transmitter
about 2 to 5 inches (5 to 13 cm) away from the
surface of the universal transmitter so that you can
still see the indicator light.
3. Using both hands, press the hand
-held transmitter
button and the desired button on the universal
transmitter. Continue to press both buttons
through Step 4.
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2-67 Air Bag Readiness Light
There is an air bag readiness light on the instrument
panel, which shows the air bag symbol. The system
checks the air bag's electrical system for malfunctions.
The light tells you if there is an electrical problem. The
system check includes the air bag sensors, the air bag
modules, the wiring and the crash sensing and
diagnostic module. For more information on the air bag
system, see ªAir Bagº in the Index.
This light will come on
when you start your engine,
and it will flash for a few
seconds. Then the light
should go out. This means
the system is ready.
If the air bag readiness light stays on after you start the
engine or comes on when you are driving, your air bag
system may not work properly. Have your vehicle
serviced right away.
The air bag readiness light should flash for a few
seconds when you turn the ignition key to RUN. If the
light doesn't come on then, have it fixed so it will be
ready to warn you if there is a problem.
Charging System Indicator Light
The charging system light
will come on briefly 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.
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2-70 Engine Coolant Temperature Gage
This gage shows the engine
coolant temperature. If the
gage pointer moves into the
red area, your engine is
too hot!
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.
The ªProblems on the Roadº section of this manual
shows you what to do. See ªEngine Overheatingº in
the Index.
Malfunction Indicator Lamp
(Service Engine Soon Light)
United States 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 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.
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3-26
When using a scrubbing action, non-abrasive cleaning
cassette, it is normal for the cassette to eject because
your unit is equipped with a cut tape detection feature
and a cleaning cassette may appear as a broken tape. To
prevent the cleaning cassette from being ejected, use the
following steps.
1. Turn the ignition to RUN or ACCESSORY.
2. Turn the radio off.
3. Press and hold the TAPE AUX button for five
seconds. The tape symbol on the display will flash
for two seconds.
4. Insert the scrubbing action cleaning cassette.
5. Eject the cleaning cassette after the manufacturer's
recommended cleaning time.
When the cleaning cassette has been ejected, the cut tape
detection feature is active again.You may also choose a non-scrubbing action, wet-type
cleaner which uses a cassette with a fabric belt to clean
the tape head. This type of cleaning cassette will not
eject on its own. A non
-scrubbing action cleaner may
not clean as thoroughly as the scrubbing type cleaner.
The use of a non
-scrubbing action, dry-type cleaning
cassette is not recommended.
After you clean the player, press and hold EJECT for
five seconds to reset the CLN indicator. The radio will
display
--- to show the indicator was reset.
Cassettes are subject to wear and the sound quality may
degrade over time. Always make sure the cassette tape is
in good condition before you have your tape
player serviced.
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6-4
If your vehicle is certified to meet California Emission
Standards (indicated on the underhood emission control
label), it is designed to operate on fuels that meet
California specifications. If such fuels are not available
in states adopting California emissions standards, your
vehicle will operate satisfactorily on fuels meeting
federal specifications, but emission control system
performance may be affected. The malfunction indicator
lamp on your instrument panel may turn on and/or your
vehicle may fail a smog
-check test. (See ªMalfunction
Indicator Lampº in the Index.) If this occurs, return to
your authorized GMC dealer for diagnosis to determine
the cause of failure. In the event it is determined that the
cause of the condition is the type of fuels used, repairs
may not be covered by your warranty.
Some gasolines that are not reformulated for low
emissions may contain an octane
-enhancing additive
called methylcyclopentadienyl manganese tricarbonyl
(MMT); ask your service station operator whether or not
the fuel contains MMT. General Motors does not
recommend the use of such gasolines. If fuels containing
MMT are used, spark plug life may be reduced and your
emission control system performance may be affected.
The malfunction indicator lamp on your instrument
panel may turn on. If this occurs, return to your
authorized GMC dealer for service.To provide cleaner air, all gasolines in the United States
are now required to contain additives that will help
prevent deposits from forming in your engine and fuel
system, allowing your emission control system to
function properly. Therefore, you should not have to add
anything to the fuel. In addition, gasolines containing
oxygenates, such as ethers and ethanol, and
reformulated gasolines may be available in your area to
contribute to clean air. General Motors recommends that
you use these gasolines, particularly if they comply with
the specifications described earlier.
NOTICE:
Your vehicle was not designed for fuel that
contains methanol. Don't use it. It can corrode
metal parts in your fuel system and also damage
plastic and rubber parts. That damage wouldn't
be covered under your warranty.
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6-29
NOTICE:

Using the wrong fluid can badly damage
brake system parts. For example, just a few
drops of mineral
-based oil, such as engine
oil, in your brake system can damage brake
system parts so badly that they'll have to be
replaced. Don't let someone put in the
wrong kind of fluid.

If you spill brake fluid on your vehicle's
painted surfaces, the paint finish can be
damaged. Be careful not to spill brake fluid
on your vehicle. If you do, wash it off
immediately. See ªAppearance Careº in
the Index.
Brake Wear
Your vehicle has four-wheel disc brakes.
Disc brake pads have built
-in wear indicators that make a
high
-pitched warning sound when the brake pads are worn
and new pads are needed. The sound may come and go or
be heard all the time your vehicle is moving (except when
you are pushing on the brake pedal firmly).
CAUTION:
The brake wear warning sound means that soon
your brakes won't work well. That could lead to
an accident. When you hear the brake wear
warning sound, have your vehicle serviced.
NOTICE:
Continuing to drive with worn-out brake pads
could result in costly brake repair.
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9-6
Lights
Air Bag Readiness 1-22, 2-67 . . . . . . . . . . . . . . . . . . . . . . .
Anti-Lock Brake System Warning 2-69, 4-7 . . . . . . . . . . . .
Brake System Warning 2-68 . . . . . . . . . . . . . . . . . . . . . . . . .
Charging System 2-67 . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Check Gages 2-75 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Gate Ajar 2-75 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Low Fuel 2-76 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Safety Belt Reminder 1-8, 2-66 . . . . . . . . . . . . . . . . . . . . . .
Security Warning 2-74 . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Service 4WD 2-74 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Service Engine Soon 2-70 . . . . . . . . . . . . . . . . . . . . . . . . . .
Loading Your Vehicle 4-41 . . . . . . . . . . . . . . . . . . . . . . . . . . .
Loading Your Vehicle for Off-Road Driving 4-15 . . . . . . . . . .
Locking Rear Axle 2-32 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Lockout Prevention 2-5 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Lockout Switch 2-32 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Locks 2-4 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Door 2-4 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Ignition Transmission Check 7-42 . . . . . . . . . . . . . . . . . . . .
Key Lock Cylinder Service 7-40 . . . . . . . . . . . . . . . . . . . . .
Power Door 2-5 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Rear Door Security 2-5 . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Loss of Control 4-13 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Low Fuel Light 2-76 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Lubricants and Fluids 7-45 . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Lubrication Service, Body 7-40 . . . . . . . . . . . . . . . . . . . . . . . .
Luggage Carrier 2-53 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Lumbar Controls 1-3 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Maintenance Record 7-47 . . . . . . . . . . . . . . . . . . . . . . . . . . .
Maintenance Schedule 7-1 . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Long Trip/Highway 7-6, 7-27 . . . . . . . . . . . . . . . . . . . . . . . Owner Checks and Services 7
-39 . . . . . . . . . . . . . . . . . . . . .
Periodic Maintenance Inspections 7-43 . . . . . . . . . . . . . . . .
Recommended Fluids and Lubricants 7-45 . . . . . . . . . . . . .
Scheduled Maintenance Services 7-4 . . . . . . . . . . . . . . . . . .
Short Trip/City 7-5, 7-7 . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Maintenance, Underbody 6-52 . . . . . . . . . . . . . . . . . . . . . . . . .
Maintenance When Trailer Towing 4-54 . . . . . . . . . . . . . . . . .
Malfunction Indicator Lamp 2-70 . . . . . . . . . . . . . . . . . . . . . .
Memory Seat 1-3 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Methanol 6-4 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Mirrors 2-44 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Convex Outside 2-45 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Electrochromic Day/Night Inside Rearview 2-44 . . . . . . . .
Heated Outside Rearview 2-45 . . . . . . . . . . . . . . . . . . . . . . .
Illuminated Visor Vanity 2-55 . . . . . . . . . . . . . . . . . . . . . . .
Outside 2-45 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Power Folding 2-46 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Model Reference iii. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Mountain Roads 4
-34 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Multifunction Lever 2-33 . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Net, Convenience 2-51 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Neutral 2-19 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
New Vehicle ªBreak-Inº 2-13 . . . . . . . . . . . . . . . . . . . . . . . . .
Night Vision 4-27 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Normal Maintenance Replacement Parts 6-61 . . . . . . . . . . . . .
Odometer 2-65 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Off-Road Driving with Your Four-Wheel-Drive
Vehicle 4-15 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Off-Road Recovery 4-11 . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Oil, Engine 6-10 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
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