2003 GMC YUKON DENALI check oil

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.
€missions 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, see your dealer or qualified service
center to prepare the vehicle for inspection.
Oil Pressure Gage
_I
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.
3-40

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
Engine Oil on page 5-13.
DL.. t kc-> dl - - jng if -..3 oil pressure is IOL- 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.
Security Light
1 This light will come on
I'
brieflywhen you turn the
key toward START.
The light will stay on until
the engine starts.
If the light flashes, the Passlock@ system has entered a
tamper mode. If the vehicle fails
to start, see Passlock@
on page
2- 17.
If the iight 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, see Content Theft-Deterrent on page 2- 16 for
additional information regarding the security light.
Cruise Control Light
The cruise light comes on
whenever you
set your
cruise control. See Cruise
Control under Turn
SignaVMultifunction Lever
on page 3-7.
3-4 1

Fuel Range GM Oil Life System
Press the fuel information button until RANGE appears
to display the remaining distance you can drive
without refueling. It’s based on fuel economy and the
fuel remaining in the tank. The display will show LOW
if
the fuel level is low.
The fuel economy data used
to determine fuel range is
an average of recent driving conditions. As your
driving conditions change, this data is gradually updated. Fuel range cannot be reset.
Average Fuel Economy
Press the fuel information button until AVG ECON
appears in the display. Average fuel economy is how
many miles per gallon your vehicle is getting based on
current and past driving conditions.
Press and hold the select button for two seconds while
AVG ECON is displayed to reset the average fuel
economy. Average fuel economy will then be calculated
starting from that point. If the average fuel economy is not
reset, it will be continually updated each time you drive.
Instant Fuel Economy
Press the fuel information button until INST ECON
appears in the display. Instant fuel economy is how
many miles per gallon your vehicle is getting at
the particular moment in time. The instant fuel economy
cannot be reset. Press the fuel information button until
ENGINE OIL LIFE
appears in the display. The GM Oil Life System shows
an estimate of the oil’s remaining useful life.
It will show
100% when the system is reset after an oil change.
It will alert you to change your oil on a schedule
consistent with your driving conditions.
Always reset the engine oil life after an oil change.
To reset the Oil Life System press and hold the select
button for five seconds while ENGINE OIL LIFE is
displayed. OIL LIFE RESET will appear on the display
for
10 seconds to let you know the system is reset.
The DIC does not replace the need
to maintain
your vehicle as recommended in the Maintenance
Schedule in this manual.
Also, the oil change reminder
will not detect dusty conditions or engine malfunctions
that may affect the oil.
Also, the oil change reminder
does not measure how much oil you have in your
engine.
So, be sure to check your oil level often.
See
Engine Oil on page 5- 13.
3-46

OIL LIFE RESET ENGINE COOLANT HOT
This message will appear on the display for about
10 seconds after resetting the change engine oil
message.
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.
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
the select button will clear this message from the DIC
display. This message will clear itself after
10 seconds
until the next igntion cycle.
LOW COOLANT LEVEL
If the engine coolant level is low, this message will
appear on the DIC. Adding coolant will clear the
message. This message will clear itself after
10 seconds
until the next igntion cycle. If
the cooling system temperature gets hot, this message
will appear in the DIC. Stop the vehicle and
let the
engine idle in PARK
(P) to allow the coolant to reach a
safe temperature. This message will clear when the
coolant temperature drops
to a safe operating
temperature.
ENGINE OVERHEATED
If the engine cooling system reaches unsafe
temperatures for operation, this message will appear in
the DIC and you will hear a chime. Stop and turn
off
the vehicle as soon as it is safe to do so to avoid severe
damage. This message will clear when the engine
has cooled
to a safe operating temperature.
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.
See
Engine Overheating on page 5-25 for further
information.
3-53

Once you are moving on the freeway, make certain you
allow a reasonable following distance. Expect
to
move slightly slower at night.
When you want to leave the freeway, move
to the
proper lane well in advance.
If you miss your exit, do
not, under any circumstances,
stop and back up. Drive
on
to the next exit.
The exit ramp can be curved, sometimes quite sharply.
The exit speed is usually posted.
Reduce your speed according
to your speedometer, not
to your sense of motion. After driving for any distance
at higher speeds, you may tend to think you are
going slower than you actually are.
Before Leaving on a Long Trip
Make sure you’re ready. Try to be well rested. If you
must start when you’re not fresh
- such as after a day’s
work
- don’t plan to make too many miles that first
part of the journey. Wear comfortable clothing and shoes
you can easily drive in.
Is your vehicle ready for a long trip? If you keep it
serviced and maintained, it’s ready
to go. If it needs
service, have it done before starting out. Of course,
you’ll find experienced and able service experts
in dealerships all across North America. They’ll be
ready and willing
to help if you need it. dere
are some things you can check before a trip:
e
e
e
e e
e
e
Windshield Washer Fluid: Is the reservior full? Are
all windows clean inside and outside?
Wiper Blades: Are they in good shape?
Fuel, Engine Oil, Other Fluids: Have you checked
all levels?
Lamps: Are they all working? Are the lenses clean?
Tires: They are vitally important
to a safe,
trouble-free trip.
Is the tread good enough for
long-distance driving? Are the tires all inflated to the
recommended pressure?
Weather Forecasts: What’s the weather outlook
along your route? Should you delay your trip a
short time
to avoid a major storm system?
Maps:
Do you have up-to-date maps?
4-34

Backing Up
Hold the bottom of the steering wheel with one hand.
Then,
to move the trailer to the left, just move that hand
to the left. To move the trailer to the right, move your
hand
to the right. Always back up slowly and, if possible,
have someone guide you.
Making Turns
Notice: Making very sharp turns while trailering
could
cause the trailer to come in contact with the
vehicle. Your vehicle could
be damaged. Avoid
making very sharp turns while trailering.
When you’re turning with a trailer, make wider turns
than normal.
Do this so your trailer won’t strike
soft shoulders, curbs, road signs, trees or other objects.
Avoid jerky or sudden maneuvers. Signal well in
advance.
Turn Signals When Towing a Trailer
The arrows on your instrument panel will flash whenever
you signal a turn or lane change. Properly hooked up,
the trailer lamps will also flash, telling other drivers
you’re about
to turn, change lanes or stop.
When towing a trailer, the arrows on your instrument panel will flash for turns even
if the bulbs on the trailer
are burned out. Thus, you may think drivers behind
4-54
you are seeing your signal when they are not. It’s
important to check occasionally to be sure the trailer
bulbs are still working.
Driving On Grades
Reduce speed and shift to a lower gear before you start
down a long or steep downgrade.
If you don’t shift
down, you might have to use your brakes
so much that
they would get hot and no longer work well.
You can tow in
DRIVE (D). You may want to shift the
transmission
to THIRD (3) or, if necessary, a lower gear
selection
if the transmission shifts too often
(e.g., under heavy loads and/or hilly conditions).
You may also want
to activate the tow/haul mode if the
transmission shifts
too often. See “Tow/Haul Mode”
under Towing a Trailer
on page 4-47.
When towing at high altitude on steep uphill grades,
consider the following: Engine coolant will boil at a lower
temperature than at normal altitudes.
If you turn your
engine
off immediately after towing at high altitude
on steep uphill grades, your vehicle may show signs
similar
to engine overheating. To avoid this, let the
engine run while parked (preferably on level ground)
with the automatic transmission in PARK (P) for a
few minutes before turning the engine
off. If you do get
the overheat warning, see Engine Overheating
on
page 5-25.

Parking on Hills
You really should not park your vehicle, with a
trailer attached, on a hill.
If something goes
wrong, your rig could start to move. People
can be injured, and both your vehicle and the
trailer can be damaged.
But if you ever have to park your rig on a hill, here’s
how to do it:
1. Apply your regular brakes, but don’t shift into
2. Have someone place chocks under the trailer
3. When the wheel chocks are in place, release the
PARK
(P) yet.
wheels.
regular brakes until the chocks absorb the load.
4. Reapply the regular brakes. Then apply your
5. Release the regular brakes.
parking brake
and shift into PARK
(P).
When You Are Ready to Leave After
Parking on a Hill
1. Apply your regular brakes and hold the pedal down
while you:
start your engine,
shift into a gear, and
release the parking brake.
2. Let up on the brake pedal.
3. Drive slowly until the trailer is clear of the chocks.
4. Stop and have someone pick up and store the
chocks.
Maintenance When Trailer Towing
Your vehicle will need service more often when you’re
pulling a trailer. See the Maintenance Schedule for more
on this. Things that are especially important in trailer
operation are automatic transmission fluid (don’t overfill),
engine
oil, axle lubricant, belts, cooling system and
brake system. Each
of these is covered in this manual,
and the Index will help you find them quickly. If
you’re trailering, it’s a good idea to review these sections
before you start your trip.
Check periodically to see that all hitch nuts and bolts
are tight.
4-55

Section 5 Service and Appearance Care
Service ............................................................ 5.3
Doing Your Own Service Work
......................... 5-3
Adding Equipment
to the Outside of Your
Vehicle
.................................................. 5-4
................................................................ Fuel 5.5
Gasoline Octane ............................................ 5.5
Gasoline Specifications ................................... 5-5
California Fuel ............................................... 5-6
Additives
....................................................... 5.6
Fuels in Foreign Countries
............................... 5-6
Filling Your Tank
............................................ 5-7
Filling a Portable Fuel Container ....................... 5.9
the Hood .................... , .................... 5.10
Hood Release ...................... ................ 5-10
Engine Compartment Overview ....... ......... 5-12
Engine Oil ....................................... ..... 5.13
Engine Air Cleaner/Filter ............................. 5.17
Automatic Transmission Fluid ......................... 5-20
Engine Coolant ......................................... 5-22
Checking Things Under
~~
Coolant Surge Tank Pressure Cap ............... 5-25
Engine Overheating ....................................... 5-25
Cooling System ............................................ 5.28
Engine Fan Noise ......................................... 5.33
Power Steering Fluid
..................................... 5-34
Windshield Washer Fluid
................................ 5.34
Brakes
........................................................ 5.36
Battery
........................................................ 5-39
Jump Starting
............................................... 5.40
All-Wheel Drive .............................................. 5.46
Rear Axle .................................. .......... 5-48
Bulb Replacement .......................................... 5-49
Halogen Bulbs .............................................. 5-49
Headlamps
.................................................. 5-49
Running Lamps
......................................... 5-50
Center High-Mounted Stoplamp (CHMSL) ......... 5-52
Taillamps ..................................................... 5-52
Replacement Bulbs ................................... 5.53
Front Turn Signal, Sidemarker and Daytime
5- 1