check engine GMC YUKON DENALI 2008 Workshop Manual

Capacities and Specications
The following approximate capacities are given in English and metric conversions. SeeRecommended Fluids and
Lubricants on page 6-12for more information.
ApplicationCapacities
English Metric
Air Conditioning RefrigerantFor the air conditioning system refrigerant charge
amount, see the refrigerant caution label located
under the hood. See your dealer/retailer for more
information.
Cooling System 18.1 qt 17.1 L
Engine Oil with Filter 6.0 qt† 5.7 L†
Fuel Tank
Regular 26.0 gal 98.4 L
Extended 31.5 gal 119.2 L
Transmission Fluid (Pan Removal and Filter Replacement) 6.0 qt 5.7 L
Transfer Case Fluid 1.5 qt 1.4 L
Wheel Nut Torque 140 lbft 190Y
†Oil lter should be changed at every oil change.
After rell, the level must be rechecked. Add enough engine coolant so that the uid is within the proper
operating range.
Engine Specications
Engine VIN Code Transmission Spark Plug Gap
6.2L V8 8 Automatic 0.040 in (1.01 mm)
5-114

Maintenance Schedule......................................6-2
Introduction...................................................6-2
Maintenance Requirements..............................6-2
Your Vehicle and the Environment....................6-2
Using the Maintenance Schedule......................6-2
Scheduled Maintenance...................................6-4
Additional Required Services............................6-6
Maintenance Footnotes...................................6-7Owner Checks and Services............................6-9
At Each Fuel Fill............................................6-9
At Least Once a Month...................................6-9
At Least Once a Year...................................6-10
Recommended Fluids and Lubricants...............6-12
Maintenance Replacement Parts.....................6-14
Engine Drive Belt Routing..............................6-15
Maintenance Record.....................................6-16
Section 6 Maintenance Schedule
6-1

Maintenance Schedule
Introduction
Important: Keep engine oil at the proper level and
change as recommended.
Have you purchased the GM Protection Plan? The Plan
supplements your new vehicle warranties. See your
Warranty and Owner Assistance booklet or your
dealer/retailer for details.
Maintenance Requirements
Notice:Maintenance intervals, checks, inspections,
replacement parts, and recommended uids and
lubricants as prescribed in this manual are
necessary to keep your vehicle in good working
condition. Any damage caused by failure to follow
scheduled maintenance might not be covered
by warranty.
Your Vehicle and the Environment
Proper vehicle maintenance not only helps to keep your
vehicle in good working condition, but also helps the
environment. All recommended maintenance is
important. Improper vehicle maintenance can even
affect the quality of the air we breathe. Improper uid
levels or the wrong tire ination can increase the level of
emissions from your vehicle. To help protect our
environment, and to keep your vehicle in good condition,
be sure to maintain your vehicle properly.
Using the Maintenance Schedule
We want to help you keep your vehicle in good working
condition. But we do not know exactly how you will
drive it. You might drive very short distances only a few
times a week. Or you might drive long distances all the
time in very hot, dusty weather. You might use your
vehicle in making deliveries. Or you might drive it to work,
to do errands, or in many other ways.
Because of all the different ways people use their
vehicles, maintenance needs vary. You might need more
frequent checks and replacements. So please read the
following and note how you drive. If you have any
questions on how to keep your vehicle in good condition,
see your dealer/retailer.
6-2

Scheduled Maintenance
When the CHANGE ENGINE OIL SOON message
comes on, it means that service is required for your
vehicle. Have your vehicle serviced as soon as possible
within the next 600 miles (1 000 km). It is possible that,
if you are driving under the best conditions, the engine oil
life system may not indicate that vehicle service is
necessary for over a year. However, the engine oil and
lter must be changed at least once a year and at this
time the system must be reset. Your dealer/retailer has
trained service technicians who will perform this work
using genuine parts and reset the system.
If the engine oil life system is ever reset accidentally,
you must service your vehicle within 3,000 miles
(5 000 km) since your last service. Remember to reset
the oil life system whenever the oil is changed. See
Engine Oil Life System on page 5-16for information on
the Engine Oil Life System and resetting the system.When the CHANGE ENGINE OIL SOON message
appears, certain services, checks, and inspections are
required. Required services are described in the
following for “MaintenanceI” and “MaintenanceII.”
Generally, it is recommended that your rst service be
MaintenanceI, your second service be MaintenanceII,
and that you alternate MaintenanceIand MaintenanceII
thereafter. However, in some cases, MaintenanceII
may be required more often.
MaintenanceI— Use MaintenanceIif the CHANGE
ENGINE OIL SOON message comes on within
10 months since the vehicle was purchased or
MaintenanceIIwas performed.
MaintenanceII— Use MaintenanceIIif the previous
service performed was MaintenanceI. Always use
MaintenanceIIwhenever the message comes on
10 months or more since the last service or if the
message has not come on at all for one year.
6-4

Scheduled Maintenance
Service MaintenanceIMaintenanceII
Change engine oil and lter. SeeEngine Oil on page 5-13. Reset oil life
system. SeeEngine Oil Life System on page 5-16.An Emission Control
Service.••
Lubricate chassis components.See footnote #.••
Visually check for any leaks or damage.See footnote (j).••
Inspect engine air cleaner lter or change indicator (if equipped). If necessary,
replace lter. SeeEngine Air Cleaner/Filter on page 5-17.See footnote (k).•
Rotate tires and check ination pressures and wear. SeeTire Inspection and
Rotation on page 5-67and “Tire Wear Inspection” inAt Least Once a Month
on page 6-9.••
Inspect brake system.See footnote (a).••
Check engine coolant and windshield washer uid levels and add uid as
needed.••
Perform any needed additional services. SeeAdditional Required Services
on page 6-6.••
Inspect suspension and steering components.See footnote (b).•
Inspect engine cooling system.See footnote (c).•
Inspect wiper blades.See footnote (d).•
Inspect restraint system components.See footnote (e).•
Lubricate body components.See footnote (f).•
Check transfer case uid level and add uid as needed.•
6-5

Additional Required Services (cont’d)
Service and Miles (Kilometers)25,000
(40 000)50,000
(80 000)75,000
(120 000)100,000
(160 000)125,000
(200 000)150,000
(240 000)
Replace spark plugs and inspect
spark plug wires.An Emission Control
Service.•
Engine cooling system service (or every
ve years, whichever occurs rst).
An Emission Control Service.
See footnote (i).•
Inspect engine accessory drive belt.
An Emission Control Service.
See footnote (l).•
Maintenance Footnotes
†The U.S. Environmental Protection Agency or the
California Air Resources Board has determined that the
failure to perform this maintenance item will not nullify
the emission warranty or limit recall liability prior to the
completion of the vehicle’s useful life. We, however, urge
that all recommended maintenance services be
performed at the indicated intervals and the maintenance
be recorded.
#Lubricate the front suspension, steering linkage, and
parking brake cable guides. Control arm ball joints
are maintenance-free.(a)Visually 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.
(b)Visually inspect front and rear suspension and
steering system for damaged, loose, or missing parts,
signs of wear, or lack of lubrication. Inspect power
steering lines and hoses for proper hook-up, binding,
leaks, cracks, chafing, etc. Visually check constant
velocity joints, rubber boots, and axle seals for leaks.
6-7

(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

At Least Once a Year
Starter Switch Check
{CAUTION:
When you are doing this inspection, the
vehicle could move suddenly. If the vehicle
moves, you or others could be injured.
1. Before you start, be sure you have enough room
around the vehicle.
2. Firmly apply both the parking brake and the
regular brake. SeeParking Brake on page 2-35.
Do not use the accelerator pedal, and be ready to
turn off the engine immediately if it starts.
3. Try to start the engine in each gear. The vehicle
should start only in PARK (P) or NEUTRAL (N).
If the vehicle starts in any other position, contact
your dealer/retailer for service.
Automatic Transmission Shift Lock
Control System Check
{CAUTION:
When you are doing this inspection, the
vehicle could move suddenly. If the vehicle
moves, you or others could be injured.
1. Before you start, be sure you have enough room
around the vehicle. It should be parked on a level
surface.
2. Firmly apply the parking brake. SeeParking Brake
on page 2-35.
Be ready to apply the regular brake immediately if
the vehicle begins to move.
3. With the engine off, turn the ignition to ON/RUN,
but do not start the engine. Without applying the
regular brake, try to move the shift lever out
of PARK (P) with normal effort. If the shift lever
moves out of PARK (P), contact your dealer/retailer
for service.
6-10

Ignition Transmission Lock Check
While parked, and with the parking brake set, try to turn
the ignition to LOCK/OFF in each shift lever position.
The ignition should turn to LOCK/OFF only
when the shift lever is in PARK (P).
The ignition key should come out only in
LOCK/OFF.
Contact your dealer/retailer if service is required.
Parking Brake and Automatic
Transmission Park (P) Mechanism Check
{CAUTION:
When you are doing this check, your vehicle
could begin to move. You or others could be
injured and property could be damaged. Make
sure there is room in front of your vehicle in
case it begins to roll. Be ready to apply the
regular brake at once should the vehicle begin
to move.Park on a fairly steep hill, with the vehicle facing
downhill. Keeping your foot on the regular brake, set the
parking brake.
To check the parking brake’s holding ability:
With the engine running and transmission in
NEUTRAL (N), slowly remove foot pressure from
the regular brake pedal. Do this until the vehicle is
held by the parking brake only.
To check the PARK (P) mechanism’s holding ability:
With the engine running, shift to PARK (P). Then
release the parking brake followed by the regular
brake.
Contact your dealer/retailer if service is required.
Hood and Liftgate Support Gas Strut
Service
Visually inspect gas strut for signs of wear, corrosion,
cracks, loss of lubricant, or other damage. Check
the hold open ability of gas strut. If necessary, replace
with genuine parts from your dealer/retailer.
Underbody Flushing Service
At least every spring, use plain water to ush any
corrosive materials from the underbody. Take care to
clean thoroughly any areas where mud and other debris
can collect.
6-11