2003 GMC YUKON DENALI oil pressure

Adding Coolant
If you need more coolant, add the proper DEX-COOL@
coolant mixture
at the surge tank, but only when the
engine
is cool.
1 “J can be burned if you sb... coolant on hot
engine parts. Coolant contains ethylene glycol, and
it will burn if the engine parts are hot
enough. Don’t spill coolant on a hot engine.
When replacing the pressure cap, make sure it is
hand-tight.
Coolant Surge Tank Pressure Cap
The coolant surge tank pressure cap must be fully
installed on the coolant surge tank. See Engine
Compartment Overview on page
5-12 for more
information on location.
Notice: Your pressure cap is a pressure-type cap
and must be tightly installed to prevent coolant
loss
and possible engine damage from overheating.
See “Capacities and Specifications” for more
information.
Engine Overheating
You will find a coolant temperature gage on your
vehicle’s instrument panel. See Engine Coolant
Temperature Gage
on page 3-36. in addition, yoti ill
find a LOW COOLANT, ENGINE COOLANT HOT,
ENGINE OVERHEATED and a REDUCED ENGINE
POWER message in the DIC on the instrument panel.
See DIC Warnings and Messages on page
3-52.
Overheated Engine Protection
Operating Mode
If an overheated engine condition exists and the
REDUCED ENGINE POWER message is displayed, an
overheat protection mode which alternates firing
groups of cylinders helps prevent engine damage.
In
this mode, you will notice a loss in power and engine
performance. This operating mode allows your vehicle to
be driven
to a safe place in an emergency. Driving
extended miles (km) and/or towing a trailer in the
overheat protection mode should be avoided.
Notice: After driving in the overheated engine
protection operating mode, to avoid engine damage,
allow the engine to cool before attempting any repair.
The engine oil will be severely degraded. Repair the cause of coolant
loss, change the oil and reset the oil
life system. See “Engine Oil” in the Index.
5-25

Cooling System
When you decide it’s safe to lift the hood, here’s what
you’ll see: If the
coolant inside the coolant surge tank
is boiling,
don’t do anything else until
it cools down. The vehicle
should be parked on a level surface.
A. Coolant Surge Tank
B. Coolant Surge Tank Pressure Cap
C. Engine Fan
1
The coolant level should
be at or above the FULL
COLD mark. If
it isn’t,
you may have a leak at the
pressure cap or in the
radiator hoses, heater
hoses, radiator, water pump or somewhere else
in the cooling system.
5-28

Adding only plain water to your cooling
system can be dangerous. Plain water, or
some other liquid such as alcohol, can boil
before the proper coolant mixture will. Your
vehicle's coolant warning system
is set for the
proper coolant mixture.
With plain water or the
wrong mixture, your engine could get too hot
but you wouldn't get the overheat warning.
Your engine could catch fire and you or others
could be burned. Use a
50/50 mixture of clean,
drinkable water and DEX
COOL@ coolant.
Notice: In cold weather, water can freeze and crack
the engine, radiator, heater core and other parts.
Use the recommended coolant and the proper
coolant mixture. You can be burned
if you spill coolant on tist
engine parts. Coolant contains ethylene glycol
and
it will burn if the engine parts are hot
enough. Don't
spill coolant on a hot engine.
1. Park the vehicle on a
level surface.
SURGE RESERVOIR
15 PSI
TANK - 105 kPa
D'EXPANSION I
You
can remove the coolant surge tank pressure
cap when the cooling system, including the coolant
surge tank pressure cap and upper radiator hose,
is no longer hot.
Turn the pressure cap slowly counterclockwise
(left) about one full turn. If you hear a hiss, wait for
that
to stop. A hiss means there is still some
pressure left.
5-31

Part B: Owner Checks and Services
Listed in this part are owner checks and services
which should be performed at the intervals specified
to
help ensure the safety, dependability and emission
control performance of your vehicle.
Be sure any necessary repairs are completed at once.
Whenever any fluids or lubricants are added
to your
vehicle, make sure they are the proper ones, as shown
in Part
D.
At Each Fuel Fill
It is important for you or a service station attendant to
perform these underhood checks at each fuel fill.
Engine Oil Level Check
Check the engine oil level and add the proper oil if
necessary. See Engine Oil on page 5-13 for further
details.
Engine Coolant Level Check
Check the engine coolant level and add DEX-COOL@
coolant mixture
if necessary. See Engine Coolant
on page 5-22 for further details.
Windshield Washer Fluid Level Check
Check the windshield washer fluid level in the windshield
washer tank and add the proper fluid
if necessary.
See Windshield Washer Fluid
on page 5-34 for further
details.
At Least Once a Month
Tire Inflation Check
Make sure tries are inflated to the correct pressures.
Don’t forget
to check your spare tire. See Tires on
page 5-55 for further details.
Cassette Tape Player Service
Clean cassette tape player. Cleaning should be done
every
50 hours of tape play. See Audio System(s)
on page 3-58 for further details.
At Least Twice a Year
Restraint System Check
Make sure the safety belt reminder light and all your
belts, buckles, latch plates, retractors and anchorages
are working properly. Look for any other loose or
damaged safety belt system parts. If you see anything
that might keep a safety belt system from doing its
job, have it repaired. Have any torn or frayed safety belts
replaced.
6-1 0

Also look for any opened or broken air bag coverings,
and have them repaired or replaced. (The air bag
system does not need regular maintenance.)
Inspect wiper blades for wear or cracking. Replace
blade inserts that appear worn or damaged or that
streak or miss areas of the windshield.
Also see
Cleaning the Outside
of Your Vehicle on page 5-81.
Spare Tire Check
At least twice a year, after the monthly inflation check of
the spare tire determines that the spare is inflated
to
the correct tire inflation pressure, make sure that
the spare tire is stored securely. Push, pull, and then
try
to rotate or turn the tire. If it moves, use the wheel
wrenchhatchet
to tighten the cable. See Changing a Flat
Tire
on page 5-63.
Engine Air Cleaner Filter Restriction
Indicator Check
Your vehicle has an engine air cleaner filter restriction
indicator located on the air cleaner in the engine
compartment. The indicator lets you know when the air
cleaner filter is dirty and needs
to be changed. Check
the indicator at least twice a year or when your engine oil is changed,
whichever occurs first. See Engine Air
Cleaner/Filter
on page 5- 17 for more information. Inspect
your air cleaner filter restriction indicator more often
if
the vehicle is used in dusty areas or under off road
conditions.
Weatherstrip Lubrication
Silicone grease on weatherstrips will make them last
longer, seal better, and not stick or squeak. Apply
silicone grease with a clean cloth. During very cold,
damp weather more frequent application may be required. See
Part D: Recommended Fluids and
Lubricants
on page 6- 15.
Automatic Transmission Check
Check the transmission fluid level; add if needed. See
Automatic Transmission Fluid on page
5-20. A fluid loss
may indicate a problem. Check the system and repair
if needed.
At Least Once a Year
Key Lock Cylinders Service
Lubricate the key lock cylinders with the lubricant
specified in Part D.

Part C: Periodic Maintenance
Inspections
Listed in this part are inspections and services which
should be performed at least twice a year (for instance,
each spring and fall).
You should let your dealer’s
service department or other qualified service center do
these jobs. Make sure any necessary repairs are
completed at once.
Proper procedures
to perform these services may be
found in a service manual. See Service Publications
Ordering Information on page
7- IO.
Steering and Suspension Inspection
Inspect the front and rear suspension and steering
system for damaged, loose or missing parts, signs of
wear or lack of lubrication. Inspect the power steering
lines and hoses for proper hook-up, binding, leaks,
cracks, chafing, etc.
Exhaust System Inspection
Inspect the complete exhaust system. Inspect the body
near the exhaust system. Look for broken, damaged,
missing or out-of-position parts as well as open seams,
holes, loose connections or other conditions which
could cause a heat build-up in the floor pan or could let
exhaust fumes into the vehicle. See Engine Exhaust
on page 2-29.
Fuel System Inspection
Engine Cooling System Inspection
Inspect the complete fuel system for damage or leaks.
Inspect the hoses and have them replaced
if they
are cracked, swollen or deteriorated. Inspect all pipes,
fittings and clamps; replace as needed. Clean the
outside of the radiator and air conditioning condenser.
To help ensure proper operation, a pressure test of
the cooling system and pressure cap is recommended
at least once a year.
Transfer Case and Front Axle
(All-Wheel Drive) Inspection
Every 12 months, or at engine oil change intervals,
check front axle and transfer case and add lubricant
when necessary.
A fluid loss could indicate a problem.
Check and have it repaired,
if needed. Check vent
hose at transfer case for kinks and proper installation.
Brake System Inspection
Inspect the complete system. Inspect brake lines and
hoses for proper hook-up, binding, leaks, cracks,
chafing, etc. Inspect disc brake pads for wear and rotors
for surface condition. Inspect other brake parts,
including calipers, parking brake, etc. You may need
to
have your brakes inspected more often if your driving
habits or conditions result in frequent braking.
6-1 4

Exit Lighting ........................................ 3-16
Extender, Safety Belt
....................................... 1-47
Exterior Lamps
......................... ~ ~ ................ 3-1 3
FabricKarpet
...
Engine Air Cleaner ..............................
Finding a P TY Station (RDS and XMTM) .....
Filter
Finding a Station
....................................
F
....
Finish Care
Finish Damage
................................
Fixed Mast Antenna .........................
Flash-to-Pass ...................................
Flat Tire .........................................
Flat Tire, Changing ..........................
Fluid
Automatic Transmission
.................
Power Steering ............................
Windshield Washer .......................
-
.....................................
..
.....
...
.... 5-78
.... 5-17
.... 3-63
.... 3-61
.... 5-81
.... 5-83
.... 3-89
...... 3-8
.... 5-63
............. 5-63
.......... 5-20
.......... 5-34
.......... 5-34
FM Stereo
..................................................... 3-87
Fog Lamps
.................................................... 3-1 5
Folding the Seatback ....................................... 1-17
Folding the Seatbacks
............................. 1-12, 1-22
Folding the Seatbacks (60/40 Split Bench Seat) .... 1-9
Following Distance
.......................................... 4-53
Footnotes
........................................ ......... 6-5
Front Axle
.................................... ... 5-47 Frontal
Air Bags
...................................... 1-77
Fuel
............................................................... 5-5
Additives ...................................................... 5-6
California Fuel
.............................................. 5-6
Filling Your Tank
........................................... 5-7
Fuels in Foreign Countries
.......................... 5-6
Gasoline Octane
....................................... 5-5
Gasoline Specifications .................................. 5-5
System Inspection ....................................... 6-14
Filling
a Portable Fuel Container
..................... 5-9
Gage
............................. .................... 3-42
Low Warning Light
....................................... 3-42
Fuel Information Button
.................................... 3-45
FUEL LEVEL LOW
......................................... 3-55
Fuses
Fuses and Circuit Breakers
........................... 5-87
Windshield Wiper
......................................... 5-87
G
Gage
Engine Coolant Temperature
............. .... 3-36
Fuel
...................................................... 3-42
Oil Pressure
........................................... 3-40
Speedometer
.......................................... 3-30
Tachometer
............................................. 3-30
Transmission Temperature
......................... 3-37
Voltmeter Gage ....................................... 3-34
Garage Door Opener
....................................... 2-38
6

........... 3-30
....... 4-13
New
Vehicle Break-In
...................................... 2-18
Normal Maintenance Replacement Parts
............ 5-98
0
Odometer ................................
Oil Off-Road Recovery
............
Engine .............. .............. 5-13
Pressure Gage
.......... .................. 3-40
OIL LIFE RESET ............................................ 3-53
OIL PRESSURE LOW
..................................... 3-53
Older Children. Restraints
................................ 1-48
Online Owner Center
........................................ 7-3
Onstar@ Personal Calling
................................. 2-37
Onstar@ Services
............................................ 2-36
Onstar@ Steering Wheel Controls
...................... 2-37
Onstar@ System
............................................. 2-36
Onstar@ Virtual Advisor
.................................... 2-37
Operating Your All-Wheel-Drive Vehicle
Off
Paved Roads .............................................. 4-1 6
Other Warning Devices
...................................... 3-6
Outlet Adjustment
............................................ 3-25
Outside Automatic Dimming Mirror with Curb
View Assist
............................................. 2-35
Convex Mirror
............................................. 2-34
Heated Mirrors
............................................ 2-35 Outside
(cont.)
Power Mirrors
............................................. 2-34
Overheated Engine Protection Operating Mode
..... 5-25
Owners. Canadian
............................................... ii
Owner’s Information
........................................ 7-11
P
Park (P)
Parking Shifting Out
of
............................................ 2-28
Brake
........................................................ 2-25
Over Things That Burn
................................. 2-29
Parking Brake and Automatic Transmission Park
(P) Mechanism Check
.................................. 6-13
Parking on Hills .............................................. 4-55
Park( P)
Shifting Into
................................................ 2-26
Part
A - Scheduled Maintenance Services ............ 6-4
Part B
- Owner Checks and Services ................ 6-10
Part C
- Periodic Maintenance Inspections .......... 6-14
Part
D - Recommended Fluids and Lubricants .... 6-15
Part E
- Maintenance Record ........................... 6-17
Passenger Air Bag Indicator
............................. 2-33
Passenger Sensing System
.......................... 1-81
PASSENGER
DOOR AJAR ........ ............ 3-56
Passing
............................................. 4-13, 4-53
Passlock@
...................................................... 2-17
Personalization Button
..................................... 3-47
Passenger
Air Bag Status Indicator
................... 3-32
10