2008 GMC YUKON DENALI fuel pressure

Under-ination also reduces fuel efficiency and tire tread
life, and may affect the vehicle’s handling and stopping
ability.
Please note that the TPMS is not a substitute for proper
tire maintenance, and it is the driver’s responsibility to
maintain correct tire pressure, even if under-ination has
not reached the level to trigger illumination of the TPMS
low tire pressure telltale.
Your vehicle has also been equipped with a TPMS
malfunction indicator to indicate when the system is not
operating properly. The TPMS malfunction indicator
is combined with the low tire pressure telltale. When the
system detects a malfunction, the telltale will ash
for approximately one minute and then remain
continuously illuminated. This sequence will continue
upon subsequent vehicle start-ups as long as the
malfunction exists.
When the malfunction indicator is illuminated, the
system may not be able to detect or signal low tire
pressure as intended. TPMS malfunctions may occur for
a variety of reasons, including the installation of
replacement or alternate tires or wheels on the vehicle
that prevent the TPMS from functioning properly.
Always check the TPMS malfunction telltale after
replacing one or more tires or wheels on your vehicle to
ensure that the replacement or alternate tires and
wheels allow the TPMS to continue to function properly.
SeeTire Pressure Monitor Operation on page 5-64, for
additional information.Federal Communications Commission
(FCC) and Industry and Science
Canada
The Tire Pressure Monitor System (TPMS) operates on
a radio frequency and complies with Part 15 of the
FCC Rules. Operation is subject to the following
two conditions:
1. This device may not cause harmful interference.
2. This device must accept any interference received,
including interference that may cause undesired
operation.
The Tire Pressure Monitor System (TPMS) operates on
a radio frequency and complies with RSS-210 of
Industry and Science Canada. Operation is subject to
the following two conditions:
1. This device may not cause interference.
2. This device must accept any interference received,
including interference that may cause undesired
operation of the device.
Changes or modications to this system by other than
an authorized service facility could void authorization to
use this equipment.
5-63

(c)Visually inspect hoses and have them replaced if
they are cracked, swollen, or deteriorated. Inspect all
pipes, fittings, and clamps; replace with genuine parts as
needed. To help ensure proper operation, a pressure test
of the cooling system and pressure cap and cleaning the
outside of the radiator and air conditioning condenser is
recommended at least once a year.
(d)Inspect wiper blades for wear, cracking, or
contamination. Clean the windshield and wiper blades, if
contaminated. Replace wiper blades that are worn or
damaged. See Windshield Wiper Blade Replacement on
page 5-53 and Windshield, Backglass, and Wiper
Blades on page 5-103for more information.
(e)Make sure the safety belt reminder light and safety
belt assemblies 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. Also see Checking the Restraint
Systems on page 1-92.
(f)Lubricate all key lock cylinders, hood latch assembly,
secondary latch, pivots, spring anchor, release pawl,
door hinges, liftgate hinge, liftgate linkage, liftgate handle
pivot points, latch bolt, fuel door hinge, locks, and
folding seat hardware. More frequent lubrication may be
required when exposed to a corrosive environment.
Applying silicone grease on weatherstrips with a clean
cloth will make them last longer, seal better, and not stick
or squeak.(g)Inspect system. Check all fuel and vapor lines and
hoses for proper hook-up, routing, and condition.
Check that the purge valve works properly, if equipped.
Replace as needed.
(h)Change automatic transmission fluid and filter if the
vehicle is mainly driven under one or more of these
conditions:
In heavy city traffic where the outside temperature
regularly reaches 90°F (32°C) or higher.
In hilly or mountainous terrain.
When doing frequent trailer towing.
Uses such as found in taxi, police, or delivery
service.
(i)Drain, flush, and refill cooling system. This service
can be complex; you should have your dealer/retailer
perform this service. See Engine Coolant on page 5-23
for what to use. Inspect hoses. Clean radiator,
condenser, pressure cap, and filler neck. Pressure test
the cooling system and pressure cap.
(j)A fluid loss in any vehicle system could indicate a
problem. Have the system inspected and repaired and
the fluid level checked. Add fluid if needed.
(k)If you drive regularly under dusty conditions, inspect
the filter at each engine oil change.
(l)Visually inspect belt for fraying, excessive cracks, or
obvious damage. Replace belt if necessary.
(m)Check vent hose at transfer case for kinks and
proper installation.
6-8

Owner Checks and Services
These owner checks and services should be performed
at the intervals specied to help ensure the safety,
dependability, and emission control performance of your
vehicle. Your dealer/retailer can assist you with these
checks and services.
Be sure any necessary repairs are completed at once.
Whenever any uids or lubricants are added to your
vehicle, make sure they are the proper ones, as shown
inRecommended Fluids and Lubricants on page 6-12.
At Each Fuel Fill
It is important to perform these underhood checks at
each fuel fill.
Engine Oil Level Check
Notice:It is important to check the engine oil
regularly and keep it at the proper level. Failure to
keep the engine oil at the proper level can cause
damage to the engine not covered by your warranty.
Check the engine oil level and add the proper oil if
necessary. SeeEngine Oil on page 5-13.
Engine Coolant Level Check
Check the engine coolant level and add DEX-COOL®
coolant mixture if necessary. SeeEngine Coolant
on page 5-23.
Windshield Washer Fluid Level Check
Check the windshield washer uid level in the windshield
washer uid reservoir and add the proper uid if
necessary.
At Least Once a Month
Tire Ination Check
Inspect your vehicle’s tires and make sure they are
inated to the correct pressures. Do not forget to check
the spare tire. SeeInflation - Tire Pressure on
page 5-60. Check to make sure the spare tire is stored
securely. SeeChanging a Flat Tire on page 5-78.
Tire Wear Inspection
Tire rotation may be required for high mileage highway
drivers prior to the Engine Oil Life System service
notication. Check the tires for wear and, if necessary,
rotate the tires. SeeTire Inspection and Rotation on
page 5-67.
6-9

G
Gage
Engine Coolant Temperature.........................3-41
Fuel..........................................................3-48
Oil Pressure...............................................3-45
Speedometer..............................................3-33
Tachometer.................................................3-33
Voltmeter Gage...........................................3-38
Garage Door Opener.......................................2-50
Gasoline
Octane........................................................ 5-5
Specications............................................... 5-5
Glove Box.....................................................2-58
GM Mobility Reimbursement Program.................. 7-6
H
Hazard Warning Flashers................................... 3-6
Head Restraints............................................... 1-8
Headlamp
Aiming.......................................................5-48
Headlamps
Bulb Replacement.......................................5-50
Daytime Running Lamps...............................3-17
Exterior Lamps............................................3-16
Flash-to-Pass............................................... 3-9Headlamps (cont.)
Halogen Bulbs............................................5-50
High/Low Beam Changer................................ 3-9
On Reminder..............................................3-17
Heated Seats................................................... 1-4
Heated Steering Wheel..................................... 3-7
Heater...........................................................3-23
Highbeam On Light.........................................3-47
High-Speed Operation, Tires.............................5-62
Highway Hypnosis...........................................4-27
Hill and Mountain Roads..................................4-28
Hood
Checking Things Under................................5-10
Release.....................................................5-10
Horn............................................................... 3-6
How to Wear Safety Belts Properly...................1-33I
Ignition Positions.............................................2-26
Infants and Young Children, Restraints...............1-52
Ination - Tire Pressure...................................5-60
Instrument Panel
Overview..................................................... 3-4
Storage Area..............................................2-59
6

Instrument Panel (I/P)
Brightness..................................................3-19
Cluster.......................................................3-32
J
Jump Starting.................................................5-40
K
Keyless Entry System....................................... 2-4
Keys............................................................... 2-3
L
Labeling, Tire Sidewall.....................................5-56
Lamps
Dome........................................................3-19
Dome Lamp Override...................................3-20
Front Reading.............................................3-20
Lap Belt........................................................1-47
Lap-Shoulder Belt...........................................1-41
LATCH System
Child Restraints...........................................1-60
Level Control..................................................4-41
License Plate Lamps.......................................5-52Liftgate, Power...............................................2-15
Liftgate/Liftglass..............................................2-13
Liftglass/Liftgate..............................................2-13
Light
Airbag Readiness........................................3-34
Antilock Brake System Warning.....................3-40
Brake System Warning.................................3-39
Charging System.........................................3-37
Cruise Control.............................................3-47
Fog Lamp..................................................3-47
Highbeam On.............................................3-47
Low Fuel Warning.......................................3-48
Malfunction Indicator....................................3-42
Oil Pressure...............................................3-46
Passenger Airbag Status Indicator..................3-35
Safety Belt Reminders..................................3-33
Security.....................................................3-46
StabiliTrak®Indicator....................................3-40
Tire Pressure..............................................3-41
Tow/Haul Mode...........................................3-47
Lighting
Entry.........................................................3-20
Exit...........................................................3-20
Lights
Exterior Lamps............................................3-16
Flash-to-Pass............................................... 3-9
High/Low Beam Changer................................ 3-9
On Reminder..............................................3-17
7