service GMC YUKON 2000 Owner's Guide

2-76 Low Traction Light
If you have the Traction
Assist System, this light
will come on when the
system is limiting wheel
spin. See ªTraction Assist
Systemº in the Index.
You may feel or hear the system working or notice a
lack of accelerator response, but this is normal.
The LOW TRACTION light also comes on briefly when
you turn your ignition to RUN. If the light doesn't come
on then, the system may require service; have it fixed so
it will be there to tell you when the Traction Assist
System is active. Slippery road conditions may exist if
the LOW TRACTION light comes on, so adjust your
driving accordingly.
Traction Off Light
If you have the Traction
Assist System, this light
should come on briefly
when you turn the ignition
to RUN.
If the light doesn't come on then, the system may
require service; have it fixed so it will be there to warn
you if the system is turned off.
If the TRACTION OFF light stays on, or comes on
when you're driving, there may be a problem with your
Traction Assist System and your vehicle may need
service. When this light is on, the system will not limit
wheel spin. Adjust your driving accordingly.

2-77
The TRACTION OFF light may come on for the
following reasons:

If you turn the system off by pressing the TAS on/off
button located to the left of the steering wheel, the
light will come on and stay on. To turn the system
back on, press the button again; the light should
go off.

If you move the shift lever to FIRST (1), the light
will come on and stay on to indicate that the Traction
Assist System is off. This is normal operation. To
turn the system back on, move the shift lever back to
a position other than FIRST (1); the light should go
off. See ªTraction Assist Systemº in the Index.

The light will come on and stay on if the TAS
automatic engagement feature has been turned off.
To turn the system on, press the TAS off/on button;
the light should go off. To turn the automatic
engagement feature back on, see ªTraction Assist
Systemº in the Index.

If the Traction Assist System is affected by an
engine
-related problem, the system will turn off and
the light will come on. Have your vehicle serviced.
Malfunction Indicator Lamp
(Service Engine Soon Light in the United
States or Check Engine Light in Canada)
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 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.

2-78
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:
Modifications made to the engine, transmission,
exhaust 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 the SERVICE ENGINE
SOON or CHECK ENGINE light to come on.
Modifications 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.
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 doesn't come on, have it repaired.
This light will also come on during a malfunction in one
of two ways:

Light Flashing
-- A misfire condition has been
detected. A misfire increases vehicle emissions and
may damage the emission control system on your
vehicle. Dealer or qualified service center diagnosis
and service may be required.

Light On Steady
-- An emission control system
malfunction has been detected on your vehicle.
Dealer or qualified service center 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.

2-79
If the light stops flashing and remains on steady,
see ªIf the Light Is On Steadyº following.
If the light continues to flash, 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 ªIf the Light
Is On Steadyº following. If the light is still flashing,
follow the previous steps, and drive the vehicle to your
dealer or qualified service center for service.
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. See ªFilling Your Tankº in the Index. 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.
Have you recently changed brands of fuel?
If so, be sure to fuel your vehicle with quality fuel (see
ªFuelº in the Index). 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, misfiring, 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,
have your dealer or qualified service center check the
vehicle. Your dealer has the proper test equipment and
diagnostic tools to fix any mechanical or electrical
problems that may have developed.

2-80
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 in order to help
your vehicle pass an inspection:
Your vehicle will not pass this inspection if the
SERVICE ENGINE SOON or 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, see your dealer or qualified service center to
prepare the vehicle for inspection.
Oil Pressure Gage
United States Canada
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).
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 some other problem causing
low oil pressure. Check your oil as soon as possible. See
ªCheck Eng Oil Pressureº and ªEngine Oilº in the Index.

2-81
CAUTION:
Don't keep driving if the oil pressure is low. If
you do, your engine can become so hot that it
catches fire. You or others could be burned.
Check your oil as soon as possible and have
your vehicle serviced.
NOTICE:
Damage to your engine from neglected oil
problems can be costly and is not covered by
your warranty.
Cruise Light (If Equipped)
United States Canada
The CRUISE light comes on whenever you set your
cruise control. See ªCruise Controlº in the Index.
Tow/Haul Light
This message is displayed
when the tow/haul mode has
been activated.
For more information, see ªTow/Haul Modeº in
the Index.

2-85
The following situations can cause the transmission to
operate at higher temperatures:

Towing a trailer

Hot outside air temperatures

Hauling a heavy load

Low transmission fluid level

High transmission fluid level

Restricted air flow to the radiator and the auxiliary
transmission oil cooler (if equipped).
A temporary solution to hotter transmission operating
temperatures may be to let the transmission cool down.
If the transmission is operated at higher temperatures on
a frequent basis, see ªScheduled Maintenanceº in the
Index for the proper transmission maintenance intervals.LOW COOLANT
This message is displayed
when the cooling system is
low on coolant.
The engine may overheat. See ªEngine Coolantº in the
Index and have your vehicle serviced as soon as you can.
CHECK COOLANT TEMP
This message is displayed
when the cooling system
temperature gets hot.
Check the coolant temperature gage and the coolant
level. See ªEngine Coolantº and ªEngine Coolant
Temperature Gageº in the Index. See ªEngine
Overheatingº in the Index for further information.

2-87 CHANGE ENGINE OIL
This message is displayed
when the engine oil needs
to be changed. The message
is only displayed for
15 seconds at the start of
each ignition cycle.
When you change the engine oil, be sure to reset the
Engine Oil Life System. See ªEngine Oil, When to
Changeº in the Index.
SECURITY
This message is displayed
when the content
theft
-deterrent system
has been activated and
also monitors the
Passlock

System.
If the security message is displayed 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 GM dealer.
SERVICE 4WD (If Equipped)
If the SERVICE 4WD
message comes on, there
may be a problem with the
automatic transfer case 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
service technician in correctly diagnosing a malfunction.
LOW WASHER FLUID
This message is displayed
when the vehicle is low on
windshield washer fluid.
The message is only
displayed for 15 seconds
each ignition cycle.
For more information, see ªWindshield Washer Fluidº in
the Index.

2-88 SERVICE RIDE CONTROL
This message is displayed
when a possible problem
exists with the Autoride

system if equipped.
For more information, see ªAutoride
º in the Index.
CARGO DOOR AJAR
This message is displayed
when the rear liftglass,
liftgate or panel doors
are ajar when the ignition
is in RUN.
LOW FUEL
This message is displayed
when your vehicle is low
on fuel.
Refer to the fuel gage for a better indication of the
amount of fuel remaining in the fuel tank.

3-36
If your vehicle is equipped with the AM-FM Stereo with
Cassette Tape Player:
1. Turn the ignition to RUN or ACCESSORY.
2. Turn the radio on.
3. Insert the scrubbing action cleaning cassette.
4. Within five seconds, press and hold the REV and
FWD buttons at the same time for three seconds.
The tape symbol on the display will flash, showing
that the cut tape detection feature is no longer active.
5. Eject the cleaning cassette after the manufacturer's
recommended cleaning time.
If your vehicle is equipped with the AM
-FM Stereo with
Cassette Tape Player and Automatic Tone Control:
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.