2005 GMC YUKON DENALI check engine

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 5-8. 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
Gasoline Octane on page 5-5. 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.
3-41

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 GM dealer can prepare the
vehicle for inspection.
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).
Oil pressure may vary with engine speed, outside
temperature and oil viscosity, but readings above the
low pressure zone indicate the normal operating range.United States
Canada
3-42

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. SeeEngine Oil on page 5-14.
{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.
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 2-19.
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 2-17for
additional information regarding the security light.
3-43

This reminder will be repeated if the ignition is on, the
vehicle is in motion, the driver is buckled and the
passenger is still unbuckled and the passenger airbag is
enabled. If the passenger’s seat belt is already
buckled, this message and chime will not come on.
Pressing any of the four DIC buttons, if equipped, will
acknowledge the message and clear it from the DIC
display. If your vehicle is not equipped with the four DIC
buttons, pressing the trip odometer reset stem will
acknowledge the message and clear it from the DIC
display.
BUCKLE SEATBELT
If your vehicle is equipped with the passenger sensing
system, this message reminds you to buckle the
driver’s seat belt. SeePassenger Sensing System on
page 1-79.
This message will display and a chime will sound when
the ignition is on, the driver’s seat belt is unbuckled
and the vehicle is in motion. You should buckle
your seat belt.
If the driver remains unbuckled when the ignition is on
and the vehicle is in motion, the reminder will be
repeated. If the driver’s seat belt is already buckled, this
message and chime will not come on.This message is an additional reminder to the Safety
Belt Reminder Light in the instrument panel cluster. See
Safety Belt Reminder Light on page 3-30.
Pressing any of the four DIC buttons, if equipped, will
acknowledge the message and clear it from the
DIC display. If your vehicle is not equipped with the
four DIC buttons, pressing the trip odometer reset stem
will acknowledge the message and clear it from the
DIC display.
CHANGE ENGINE OIL
This message is displayed when the engine oil needs to
be changed. SeeEngine Oil Life System on page 5-17for
information on how to reset the message. This message
will clear itself after 10 seconds until the next ignition
cycle. SeeScheduled Maintenance on page 6-4and
Engine Oil on page 5-14for more information.
CHARGING SYSTEM FAILURE
On some vehicles, if there is a problem with the generator
and battery charging system, this message will appear on
the DIC, a chime will sound and the charging system light
on the instrument panel cluster will come on. See
Charging System Light on page 3-33andVoltmeter Gage
on page 3-34for more information. Driving with this
problem could drain your battery. Turn off all unnecessary
accessories. Stop and turn off the vehicle as soon as it is
safe to do so. Have the electrical system checked by your
GM dealer immediately.
3-51

CHECK OIL LEVEL
If the oil level in the vehicle is low, this message will
appear on the DIC. Check the oil level and correct it as
necessary. You may need to let the vehicle cool or warm
up and cycle the ignition to be sure this message will
clear. Once the problem is corrected, pressing any of the
four DIC buttons, if equipped, will clear the message from
the DIC display. If your vehicle is not equipped with the
four DIC buttons, pressing the trip odometer reset stem
will clear the message from the DIC display. This
message will clear itself after 10 seconds until the next
ignition cycle. SeeEngine Oil on page 5-14for additional
information.
CHECK TIRE PRESSURE
If your vehicle is equipped with the tire pressure monitor
system, and a low tire pressure is detected in any of the
vehicle’s tires, this message will appear on the DIC.
Pressing any of the four DIC buttons, if equipped, will
clear the message from the DIC display. If your vehicle is
not equipped with the four DIC buttons, pressing the trip
odometer reset stem will clear the message from the DIC
display. It will appear at each ignition cycle until the tires
are inated to the correct ination pressure.
CHECK WASHER FLUID
If the washer uid level is low, this message will appear
on the DIC. Adding washer uid will clear the message.
SeeWindshield Washer Fluid on page 5-37. Pressing
any of the four DIC buttons, if equipped, will clear
the message from the DIC display. If your vehicle is not
equipped with the four DIC buttons, pressing the trip
odometer reset stem will clear the message from
the DIC display. This message will clear itself after
10 seconds until the next ignition cycle.
DRIVER DOOR AJAR
If the driver’s door is not fully closed and the vehicle is
in a drive gear, this message will appear on the
display and you will hear a chime. Stop and turn off the
vehicle, check the door for obstacles and close the
door again. Check to see if the message still appears
on the DIC. Pressing any of the four DIC buttons,
if equipped, will clear the message from the DIC display.
If your vehicle is not equipped with the four DIC
buttons, pressing the trip odometer reset stem will clear
the message from the DIC display.
3-52

LEFT REAR DOOR AJAR
If the driver’s side rear door is not fully closed and the
vehicle is in a drive gear, this message will appear
on the display and you will hear a chime. Stop and turn
off the vehicle, check the door for obstacles and
close the door again. Check to see if the message still
appears on the DIC. Pressing any of the four DIC
buttons, if equipped, will clear the message from the
DIC display. If your vehicle is not equipped with the four
DIC buttons, pressing the trip odometer reset stem
will clear the message from the DIC display.
LOW COOLANT LEVEL
If your vehicle is equipped with low coolant level sensor,
this message will appear on the DIC if the engine coolant
level is low. Adding coolant will clear the message. See
Cooling System on page 5-30. Pressing any of the four
DIC buttons, if equipped, will acknowledge the message
and clear it from the DIC display. If your vehicle is not
equipped with the four DIC buttons, pressing the trip
odometer reset stem will acknowledge the message and
clear it from the DIC display.
Notice:Engine damage from running your engine
without coolant is not covered by your warranty. See
“Overheated Engine Protection Operating Mode”
in the Index for information on driving to a safe
place in an emergency.
OIL LIFE RESET
This message will appear on the display for about
10 seconds after resetting the change engine oil
message. See “Engine Oil Life System” underDIC
Operation and Displays on page 3-47andEngine Oil on
page 5-14for more information.
OIL PRESSURE LOW
If low oil pressure levels occur, this message will be
displayed on the DIC and a chime will sound. Stop the
vehicle as soon as safely possible and do not operate
it until the cause of the low oil pressure has been
corrected. Check your oil as soon as possible and have
your vehicle serviced by your GM dealer. SeeEngine
Oil on page 5-14.
Notice:If you drive your vehicle while the engine
oil pressure is low, severe engine damage may
occur. If a low oil pressure warning appears on the
Driver Information Center (DIC), stop the vehicle
as soon as possible. Do not drive the vehicle until
the cause of the low oil pressure is corrected.
SeeEngine Oil on page 5-14for more information.
3-54

PASSENGER DOOR AJAR
If the passenger’s door is not fully closed and the
vehicle is in a drive gear, this message will appear on
the display and you will hear a chime. Stop and turn off
the vehicle, check the door for obstacles and close
the door again. Check to see if the message still
appears on the DIC. Pressing any of the four DIC
buttons, if equipped, will clear the message from the DIC
display. If your vehicle is not equipped with the four
DIC buttons, pressing the trip odometer reset stem will
clear the message from the DIC display.
REAR ACCESS OPEN
If the liftgate is open while the ignition is in RUN, this
message will appear on the DIC and you will hear
a chime. Turn off the vehicle and check the liftgate.
Restart the vehicle and check for the message on the
DIC display. Pressing any of the four DIC buttons,
if equipped, will clear the message from the DIC display.
If your vehicle is not equipped with the four DIC
buttons, pressing the trip odometer reset stem will clear
the message from the DIC display.
REDUCED ENGINE POWER
This message is displayed and you will hear a chime
when the cooling system temperature gets too hot and
the engine further enters the engine coolant protection
mode. SeeEngine Overheating on page 5-28for further
information.
REPLACE LIFTGATE FUSE
This message will be displayed if the liftgate lock
malfunctions and/or the liftgate fuse blows. For more
information on fuses, seeFuses and Circuit Breakers on
page 5-105. If the message returns after replacing the
fuse, see your GM dealer for service.
RIGHT REAR DOOR AJAR
If the passenger’s side rear door is not fully closed and
the vehicle is in a drive gear, this message will
appear on the display and you will hear a chime. Stop
and turn off the vehicle, check the door for obstacles and
close the door again. Check to see if the message
still appears on the DIC. Pressing any of the four DIC
buttons, if equipped, will clear the message from the DIC
display. If your vehicle is not equipped with the four
DIC buttons, pressing the trip odometer reset stem will
clear the message from the DIC display.
3-55

SERVICE RIDE CONTROL
If a problem occurs with the suspension system, this
message will appear on the DIC. If this message
appears, stop and turn off the vehicle. Restart the
vehicle and check for the message on the DIC display.
If the message is still displayed or appears again
when you begin driving, the suspension system needs
service. See your GM dealer.
SERVICE STABILITY
If you ever see the SERVICE STABILITY message, it
means there may be a problem with your StabiliTrak®
system. If you see this message, try to reset the system.
Stop; turn off the engine; then start the engine again.
If the SERVICE STABILITY message still comes
on, it means there is a problem. You should see your
GM dealer for service. The vehicle is safe to drive,
however, you do not have the benet of StabiliTrak
®,so
reduce your speed and drive accordingly.
SERVICE TIRE MONITOR
If your vehicle is equipped with the tire pressure monitor
system, this message will be displayed if any of the
tire monitor sensors have malfunctioned or if all the
tire monitor sensors have not been programmed
successfully. Pressing any of the four DIC buttons, if
equipped, will clear the message from the DIC display.
If your vehicle is not equipped with the four DIC
buttons, pressing the trip odometer reset stem will clear
the message from the DIC display. The message will
appear at each ignition cycle until the system is
serviced. See your GM dealer.
STABILITY SYS ACTIVE
You may see the STABILITY SYS ACTIVE message on
the DIC. It means that an advanced computer-controlled
system has come on to help your vehicle continue to
go in the direction in which you are steering. StabiliTrak
®
activates when the computer senses that your vehicle
is just starting to spin, as it might if you hit a patch of ice
or other slippery spot on the road. When the system
activates, you may hear a noise or feel a vibration in the
brake pedal. This is normal. When the STABILITY
SYS ACTIVE message is on, you should continue to
steer in the direction you want to go. The system
is designed to help you in bad weather or other difficult
driving situations by making the most of whatever
road conditions will permit.
3-57