check engine light GMC YUKON DENALI 2008 Owners Manual

The vehicle cannot be remote started if the key is in the
ignition, the hood is not closed, or if there is an
emission control system malfunction and the check
engine light comes on.
Also, the engine will turn off during a remote vehicle
start if the coolant temperature gets too high or if the oil
pressure gets low.
Vehicles that have the remote vehicle start feature are
shipped from the factory with the remote vehicle
start system enabled. The system may be enabled or
disabled through the DIC. See “REMOTE START” under
DIC Vehicle Customization (With DIC Buttons) on
page 3-64for additional information. If your vehicle does
not have DIC buttons, see your dealer/retailer to
enable or disable the remote vehicle start system.″
Remote Start Ready
If your vehicle does not have the remote vehicle start
feature, it may have the remote start ready feature. This
feature allows your dealer/retailer to add the
manufacturer’s remote vehicle start feature.
If your vehicle has the remote start ready feature, the
RKE transmitter will have an extended range that allows
locking or unlocking of the vehicle from approximately
197 feet (60 m) away.
See your dealer/retailer if you would like to add the
manufacturer’s remote vehicle start feature to your
vehicle.
Doors and Locks
Door Locks
{CAUTION:
Unlocked doors can be dangerous.
Passengers, especially children, can easily
open the doors and fall out of a moving
vehicle. When a door is locked, the handle
will not open it. You increase the chance
of being thrown out of the vehicle in a
crash if the doors are not locked. So, wear
safety belts properly and lock the doors
whenever you drive.
Young children who get into unlocked
vehicles may be unable to get out. A child
can be overcome by extreme heat and can
suffer permanent injuries or even death
from heat stroke. Always lock your vehicle
whenever you leave it.
Outsiders can easily enter through an
unlocked door when you slow down or
stop your vehicle. Locking your doors can
help prevent this from happening.
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PASS-Key®III+ Operation
Your vehicle has PASS-Key®III+ (Personalized
Automotive Security System) theft-deterrent system.
PASS-Key
®III+ is a passive theft-deterrent system.
The system is automatically armed when the key
is removed from the ignition.
The system is automatically disarmed when the key is
turned to ON/RUN, ACC/ACCESSORY or START
from the LOCK/OFF position.
You do not have to manually arm or disarm the system.
The security light will come on if there is a problem
with arming or disarming the theft-deterrent system.
When the PASS-Key
®III+ system senses that someone
is using the wrong key, it prevents the vehicle from
starting. Anyone using a trial-and-error method to start
the vehicle will be discouraged because of the high
number of electrical key codes.
If the engine does not start and the security light on the
instrument panel cluster comes on when trying to
start the vehicle, there may be a problem with your
theft-deterrent system. Turn the ignition off and try again.If the engine still does not start, and the key appears to
be undamaged, try another ignition key. At this time,
you may also want to check the fuse, seeFuses
and Circuit Breakers on page 5-108. If the engine still
does not start with the other key, your vehicle needs
service. If your vehicle does start, the rst key may be
faulty. See your dealer/retailer who can service the
PASS-Key
®III+ to have a new key made. In an
emergency, contact Roadside Assistance.
It is possible for the PASS-Key
®III+ decoder to learn
the transponder value of a new or replacement key. Up
to 10 keys may be programmed for the vehicle. The
following procedure is for programming additional keys
only. If all the currently programmed keys are lost or
do not operate, you must see your dealer/retailer
or a locksmith who can service PASS-Key
®III+ to have
keys made and programmed to the system.
See your dealer/retailer or a locksmith who can service
PASS-Key
®III+ to get a new key blank that is cut
exactly as the ignition key that operates the system.
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Warning Lights, Gages, and
Indicators
This part describes the warning lights and gages on
your vehicle. The pictures help to 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
the 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
the details show on the next few pages, some warning
lights come on briey when you start the engine just
to let you know they are 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 is a problem with your vehicle.
When one of the warning lights comes on and stays on
as 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 vehicle’s
warning lights and gages. They can be a big help.
Your vehicle also has a Driver Information Center (DIC)
that works along with warning lights and gages. See
DIC Warnings and Messages on page 3-56for
more information.
3-31

Speedometer and Odometer
The speedometer lets you see your speed in both miles
per hour (mph) and kilometers per hour (km/h).
The odometer mileage can be checked without the
vehicle running. Simply press the trip stem on the
instrument panel cluster.
If your vehicle ever 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.
Press the reset button, located on the instrument panel
cluster next to the trip odometer display, to toggle
between the trip odometer and the regular odometer.
Holding the reset button for approximately one second
while the trip odometer is displayed will reset it.
To display the odometer reading with the ignition off,
press the reset button.
Tachometer
Your tachometer displays the engine speed in
revolutions per minute (rpm).
Safety Belt Reminders
Safety Belt Reminder Light
When the engine is started, a chime will come on for
several seconds to remind people to fasten their safety
belts, unless the driver’s safety belt is already buckled.
The safety belt light will
also come on and stay on
for several seconds, then it
will ash for several more.
This chime and light is repeated if the driver remains
unbuckled and the vehicle is in motion. If the driver’s belt
is already buckled, neither the chime nor the light will
come on.
3-33

Passenger Safety Belt Reminder Light
Several seconds after the engine is started, a chime
will sound for several seconds to remind the front
passenger to buckle their safety belt. This would only
occur if the passenger airbag is enabled. SeePassenger
Sensing System on page 1-85for more information.
The passenger safety belt light, located on the
instrument panel, will come on and stay on for several
seconds and then ash for several more.
This chime and light are
repeated if the passenger
remains unbuckled and
the vehicle is in motion.
If the passenger’s safety belt is buckled, neither the
chime nor the light will come on.
Airbag Readiness Light
There is an airbag readiness light on the instrument
panel cluster, which shows the airbag symbol. The
system checks the airbag’s electrical system for
malfunctions. The light tells you if there is an electrical
problem. The system check includes the airbag
sensor, the pretensioners, the airbag modules, the
wiring and the crash sensing and diagnostic module.
For more information on the airbag system, seeAirbag
System on page 1-75.
This light will come on
when you start your
vehicle, and it will ash for
a few seconds. The
light should go out and the
system is ready.
If the airbag readiness light stays on after you start the
vehicle or comes on when you are driving, your
airbag system may not work properly. Have your vehicle
serviced right away.
3-34

{CAUTION:
If the airbag readiness light stays on after you
start your vehicle, it means the airbag system
may not be working properly. The airbags 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 airbag
readiness light stays on after you start your
vehicle.
The airbag readiness light should ash for a few
seconds when you start the engine. If the light does not
come on then, have it xed immediately. If there is a
problem with the airbag system, an airbag Driver
Information Center (DIC) message may also come on.
SeeDIC Warnings and Messages on page 3-56for
more information.
Passenger Airbag Status Indicator
Your vehicle has the passenger sensing system.
Your overhead console has a passenger airbag status
indicator.
When you start the vehicle, the passenger airbag status
indicator will light ON and OFF, or the symbol for on
and off, for several seconds as a system check.
Then, after several more seconds, the status indicator
will light either ON or OFF, or either the on or off symbol
to let you know the status of the right front passenger’s
frontal airbag.United States
Canada
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If, after several seconds, both status indicator lights
remain on, or if there are no lights at all, there may be a
problem with the lights or the passenger sensing
system. See your dealer/retailer for service.
{CAUTION:
If the airbag readiness light in the instrument
panel cluster ever comes on and stays on, it
means that something may be wrong with the
airbag system. If this ever happens, have the
vehicle serviced promptly, because an
adult-size person sitting in the right front
passenger’s seat may not have the protection
of the airbag(s). SeeAirbag Readiness Light
on page 3-34for more on this, including
important safety information.
Charging System Light
This 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. A charging system
Driver Information Center (DIC) message may also
appear. SeeDIC Warnings and Messages on page 3-56
for more information. This light could indicate that you
have problems with a generator drive belt, or another
electrical problem. Have it checked right away. 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.
3-37

Engine Coolant Temperature Gage
This gage shows the engine coolant temperature.
It also provides an indicator of how hard your vehicle is
working. During a majority of the operation, the gage
will read 210°F (100°C) or less. If you are pulling a load
or going up hills, it is normal for the temperature to
uctuate and approach the 250°F (122°C) mark. If the
gage reaches the 260°F (125°C) mark, it indicates
that the cooling system is working beyond its capacity.
SeeEngine Overheating on page 5-26.
Tire Pressure Light
This light comes on briey
when the engine is started.
This light will also come on when one or more of your
tires are signicantly underinated.
A tire pressure message in the Driver Information
Center (DIC), may accompany the light. SeeDIC
Warnings and Messages on page 3-56for more
information.
Stop and check your tires as soon as it is safe to do so.
If underinated, inate to the proper pressure. See
Tires on page 5-55for more information.
If a problem is detected with the Tire Pressure Monitor
System, this light will ash for approximately
60 seconds and then stay on solid for the remainder of
the ignition cycle. SeeTire Pressure Monitor System
on page 5-62for more information. United States
Canada
3-41

Malfunction Indicator Lamp
Check Engine Light
A computer system called OBD II (On-Board
Diagnostics-Second Generation) monitors operation of
the fuel, ignition, and emission control systems. It makes
sure 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 an OBD II
problem and service is
required.
Malfunctions often are indicated by the system before
any problem is apparent. This can 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, the emission controls
might not work as well, your vehicle’s fuel economy
might not be as good, and the engine might not
run as smoothly. This could lead to costly repairs
that might 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 can cause this light to come on.
Modications to these systems could lead to costly
repairs not covered by your warranty. This could
also result in a failure to pass a required Emission
Inspection/Maintenance test. SeeAccessories
and Modifications on page 5-3.
This light comes on, as a check to show it is working,
when the ignition is turned ON/RUN but the engine is not
running. If the light does not come on, have it repaired.
This light also comes on during a malfunction in
one of two ways:
Light Flashing— A misre condition has been
detected. A misre increases vehicle emissions
and could damage the emission control system on
your vehicle. Diagnosis and service might be
required.
Light On Steady— An emission control system
malfunction has been detected on your vehicle.
Diagnosis and service might be required.
3-42

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/retailer can check the vehicle. Your
dealer/retailer has the proper test equipment and
diagnostic tools to x any mechanical or electrical
problems that might have developed.
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.
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