service GMC SIERRA 2008 Repair Manual

Electric Brake Control Wiring
Provisions
These wiring provisions are included with your vehicle
as part of the trailer wiring package. These provisions
are for an electric brake controller. The instrument panel
contains blunt cut wires near the data link connector
for the trailer brake controller. The harness contains the
following wires:
Dark Blue: Brake Signal to Trailer Connector
Red/Black: Battery
Light Blue/White: Brake Switch
White: Ground
It should be installed by your dealer or a qualied
service center.
If your vehicle is equipped with an ITBC, the blunt cuts
exist, but are not connected further in the harness. If
you install an aftermarket trailer brake controller,
the ITBC must be disconnected. Do not power both
ITBC and aftermarket controllers to control the trailer
brakes at the same time.
Auxiliary Battery
The auxiliary battery provision can be used to supply
electrical power to additional equipment that you
may choose to add, such as a slide-in camper. If your
vehicle has this provision, this relay will be located
on the driver’s side of the vehicle, next to the underhood
electrical center.
Be sure to follow the proper installation instructions that
are included with any electrical equipment that you
install.
Notice:Leaving electrical equipment on for
extended periods will drain the battery. Always turn
off electrical equipment when not in use and do
not use equipment that exceeds the maximum
amperage rating for the auxiliary battery provision.
4-93

Service............................................................5-4
Accessories and Modications..........................5-4
California Proposition 65 Warning.....................5-4
California Perchlorate Materials Requirements.....5-5
Doing Your Own Service Work.........................5-5
Adding Equipment to the Outside of Your
Vehicle......................................................5-6
Fuel................................................................5-6
Gasoline Octane............................................5-6
Gasoline Specications....................................5-6
California Fuel...............................................5-7
Additives.......................................................5-7
Fuel E85 (85% Ethanol)..................................5-8
Fuels in Foreign Countries...............................5-9
Filling the Tank............................................5-10
Filling a Portable Fuel Container.....................5-12
Checking Things Under the Hood....................5-12
Hood Release..............................................5-13
Engine Compartment Overview.......................5-14
Engine Oil (Gasoline Engine)..........................5-15
Engine Oil Life System..................................5-18
Engine Air Cleaner/Filter
(Gasoline Engines)....................................5-19Automatic Transmission Fluid
(6-Speed Transmission)..............................5-22
Automatic Transmission Fluid
(4-Speed Transmission)..............................5-25
Engine Coolant.............................................5-28
Coolant Surge Tank Pressure Cap..................5-30
Engine Overheating.......................................5-30
Overheated Engine Protection Operating Mode
(V8 Engines Only).....................................5-33
Cooling System............................................5-34
Engine Fan Noise.........................................5-39
Power Steering Fluid.....................................5-39
Windshield Washer Fluid................................5-40
Brakes........................................................5-42
Battery........................................................5-45
Jump Starting...............................................5-46
Rear Axle.......................................................5-51
Four-Wheel Drive............................................5-52
Front Axle......................................................5-54
Noise Control System.....................................5-56
Tampering with Noise Control System
Prohibited.................................................5-56
Section 5 Service and Appearance Care
5-1

Headlamp Aiming...........................................5-56
Bulb Replacement..........................................5-59
Halogen Bulbs..............................................5-59
Headlamps..................................................5-60
Center High-Mounted Stoplamp (CHMSL) and
Cargo Lamp.............................................5-61
Pickup Box Identication and Fender
Marker Lamps...........................................5-62
Taillamps, Turn Signal, Stoplamps and
Back-up Lamps.........................................5-62
License Plate Lamp......................................5-64
Replacement Bulbs.......................................5-65
Windshield Wiper Blade Replacement..............5-65
Tires..............................................................5-66
Tire Sidewall Labeling...................................5-67
Tire Terminology and Denitions.....................5-71
Ination - Tire Pressure.................................5-74
Dual Tire Operation.......................................5-76
Tire Pressure Monitor System.........................5-76
Tire Pressure Monitor Operation.....................5-78
Tire Inspection and Rotation...........................5-81
When It Is Time for New Tires.......................5-84
Buying New Tires.........................................5-84Different Size Tires and Wheels......................5-86
Uniform Tire Quality Grading..........................5-86
Wheel Alignment and Tire Balance..................5-88
Wheel Replacement......................................5-88
Tire Chains..................................................5-90
If a Tire Goes Flat........................................5-91
Changing a Flat Tire.....................................5-92
Removing the Spare Tire and Tools................5-93
Removing the Flat Tire and Installing the
Spare Tire................................................5-98
Secondary Latch System..............................5-105
Storing a Flat or Spare Tire and Tools...........5-108
Spare Tire.................................................5-112
Appearance Care
..........................................5-112
Interior Cleaning.........................................5-112
Fabric/Carpet..............................................5-114
Leather......................................................5-114
Instrument Panel, Vinyl, and Other Plastic
Surfaces.................................................5-115
Care of Safety Belts....................................5-115
Weatherstrips.............................................5-115
Washing Your Vehicle..................................5-116
Cleaning Exterior Lamps/Lenses....................5-116
Finish Care................................................5-116
Section 5 Service and Appearance Care
5-2

Windshield and Wiper Blades.......................5-117
Aluminum or Chrome-Plated
Wheels and Trim.....................................5-118
Tires.........................................................5-119
Sheet Metal Damage...................................5-119
Finish Damage...........................................5-119
Underbody Maintenance...............................5-119
Chemical Paint Spotting...............................5-120
Vehicle Care/Appearance Materials................5-120
Vehicle Identication.....................................5-121
Vehicle Identication Number (VIN)................5-121
Service Parts Identication Label...................5-122Electrical System..........................................5-122
Add-On Electrical Equipment.........................5-122
Windshield Wiper Fuses...............................5-123
Power Windows and Other Power Options......5-123
Fuses and Circuit Breakers..........................5-123
Instrument Panel Fuse Block........................5-124
Center Instrument Panel Fuse Block..............5-125
Underhood Fuse Block................................5-126
Capacities and Specications........................5-130
Section 5 Service and Appearance Care
5-3

Service
For service and parts needs, visit your dealer/retailer.
You will receive genuine GM parts and GM-trained and
supported service people.
Genuine GM parts have one of these marks:
Accessories and Modications
When non-dealer/non-retailer accessories are added to
your vehicle they can affect your vehicle’s performance
and safety, including such things as, airbags, braking,
stability, ride and handling, emissions systems,
aerodynamics, durability, and electronic systems like
antilock brakes, traction control and stability control.
Some of these accessories could even cause
malfunction or damage not covered by warranty.
GM Accessories are designed to complement and
function with other systems on your vehicle. Your GM
dealer/retailer can accessorize your vehicle using
genuine GM Accessories. When you go to your GM
dealer/retailer and ask for GM Accessories, you will
know that GM-trained and supported service technicians
will perform the work using genuine GM Accessories.
Also, seeAdding Equipment to Your Airbag-Equipped
Vehicle on page 1-85.
California Proposition 65 Warning
Most motor vehicles, including this one, contain and/or
emit chemicals known to the State of California to
cause cancer and birth defects or other reproductive
harm. Engine exhaust, many parts and systems
(including some inside the vehicle), many uids, and
some component wear by-products contain and/or emit
these chemicals.
5-4

California Perchlorate Materials
Requirements
Certain types of automotive applications, such as airbag
initiators, seat belt pretensioners, and lithium batteries
contained in remote keyless entry transmitters, may
contain perchlorate materials. Special handling may be
necessary. For additional information, see
www.dtsc.ca.gov/hazardouswaste/perchlorate.
Doing Your Own Service Work
{CAUTION:
You can be injured and your vehicle could be
damaged if you try to do service work on a
vehicle without knowing enough about it.
CAUTION: (Continued)
CAUTION: (Continued)

Be sure you have sufficient knowledge,
experience, the proper replacement parts,
and tools before you attempt any vehicle
maintenance task.
Be sure to use the proper nuts, bolts, and
other fasteners. English and metric
fasteners can be easily confused. If you
use the wrong fasteners, parts can later
break or fall off. You could be hurt.
If you want to do some of your own service work, you
should use the proper service manual. It tells you much
more about how to service your vehicle than this
manual can. To order the proper service manual, see
Service Publications Ordering Information on page 7-15.
Your vehicle has an airbag system. Before attempting
to do your own service work, seeServicing Your
Airbag-Equipped Vehicle on page 1-84.
You should keep a record with all parts receipts and list
the mileage and the date of any service work you
perform. SeeMaintenance Record on page 6-19.
5-5

Adding Equipment to the Outside of
Your Vehicle
Things you might add to the outside of your vehicle can
affect the airow around it. This can cause wind noise
and can affect fuel economy and windshield washer
performance. Check with your dealer/retailer before
adding equipment to the outside of your vehicle.
Fuel
If your vehicle has a diesel engine, see “Diesel Fuel
Requirements and Fuel System” in the DURAMAX®
Diesel manual.
For vehicles with gasoline engines, please read this.
Gasoline
Use of the recommended fuel is an important part of the
proper maintenance of your vehicle. To help keep the
engine clean and maintain optimum vehicle
performance, we recommend the use of gasoline
advertised as TOP TIER Detergent Gasoline.
The 8th digit of the Vehicle Identication Number (VIN)
shows the code letter or number that identies your
vehicle’s engine. The VIN is at the top left of the
instrument panel. SeeVehicle Identification Number
(VIN) on page 5-121.If your vehicle has the 5.3L V8 engine (VIN Code 0) or
the 5.3L V8 engine (VIN Code 3), you can use either
regular unleaded gasoline or ethanol fuel containing up
to 85% ethanol (E85); also seeFuel E85 (85% Ethanol)
on page 5-8. In all other gasoline engines, use only
regular unleaded gasoline.
Gasoline Octane
Use regular unleaded gasoline with a posted octane
rating of 87 or higher. If the octane rating is less than 87,
you might notice an audible knocking noise when you
drive, commonly referred to as spark knock. If this
occurs, use a gasoline rated at 87 octane or higher as
soon as possible. If you are using gasoline rated at
87 octane or higher and you hear heavy knocking, the
engine needs service.
Gasoline Specications
At a minimum, gasoline should meet ASTM specication
D 4814 in the United States or CAN/CGSB-3.5 or 3.511
in Canada. Some gasolines contain an octane-enhancing
additive called methylcyclopentadienyl manganese
tricarbonyl (MMT). We recommend against the use of
gasolines containing MMT. SeeAdditives on page 5-7for
additional information.
5-6

California Fuel
If your vehicle is certied to meet California Emissions
Standards, it is designed to operate on fuels that meet
California specications. See the underhood emission
control label. If this fuel is not available in states adopting
California emissions standards, your vehicle will operate
satisfactorily on fuels meeting federal specications, but
emission control system performance might be affected.
The malfunction indicator lamp could turn on and your
vehicle might fail a smog-check test. SeeMalfunction
Indicator Lamp on page 3-48. If this occurs, return to your
authorized dealer/retailer for diagnosis. If it is determined
that the condition is caused by the type of fuel used,
repairs might not be covered by your warranty.
Additives
To provide cleaner air, all gasolines in the United States
are now required to contain additives that help prevent
engine and fuel system deposits from forming, allowing
the emission control system to work properly. In most
cases, you should not have to add anything to the fuel.
However, some gasolines contain only the minimum
amount of additive required to meet U.S. Environmental
Protection Agency regulations. To help keep fuel injectors
and intake valves clean, or if your vehicle experiences
problems due to dirty injectors or valves, look for gasolinethat is advertised as TOP TIER Detergent Gasoline. Also,
your dealer/retailer has additives that will help correct and
prevent most deposit-related problems.
Gasolines containing oxygenates, such as ethers and
ethanol, and reformulated gasolines might be available
in your area. We recommend that you use these
gasolines, if they comply with the specications
described earlier. However, E85 (85% ethanol) and
other fuels containing more than 10% ethanol must
not be used in vehicles that were not designed for
those fuels.
Notice:Your vehicle was not designed for fuel that
contains methanol. Do not use fuel containing
methanol. It can corrode metal parts in the fuel
system and also damage plastic and rubber parts.
That damage would not be covered under your
warranty.
Some gasolines that are not reformulated for low
emissions can contain an octane-enhancing additive
called methylcyclopentadienyl manganese tricarbonyl
(MMT); ask the attendant where you buy gasoline
whether the fuel contains MMT. We recommend against
the use of such gasolines. Fuels containing MMT can
reduce the life of spark plugs and the performance of the
emission control system could be affected. The
malfunction indicator lamp might turn on. If this occurs,
return to your dealer/retailer for service.
5-7

Fuel E85 (85% Ethanol)
The 8th digit of the Vehicle Identication Number (VIN)
shows the code letter or number that identies your
vehicle’s engine. The VIN is at the top left of the
instrument panel. SeeVehicle Identification Number
(VIN) on page 5-121.
If your vehicle has the 5.3L V8 engine (VIN Code 0) or
the 5.3L V8 engine (VIN Code 3), you can use either
regular unleaded gasoline or ethanol fuel containing up
to 85% ethanol (E85); also seeFuel on page 5-6.Inall
other engines, use only the unleaded gasoline described
underGasoline Octane on page 5-6.
Only vehicles that have the 5.3L V8 engine
(VIN Code 0) or the 5.3L V8 engine (VIN Code 3) can
use 85% ethanol fuel (E85). We encourage the use
of E85 in vehicles that are designed to use it. The
ethanol in E85 is a “renewable” fuel, meaning it is made
from renewable sources such as corn and other crops.Many service stations will not have an 85% ethanol fuel
(E85) pump available. The U. S. Department of
Energy has an alternative fuels website
(www.eere.energy.gov/afdc/infrastructure/locator.html)
that can help you nd E85 fuel. Those stations that
do have E85 should have a label indicating ethanol
content. Do not use the fuel if the ethanol content
is greater than 85%.
At a minimum, E85 should meet ASTM Specication
D 5798. By denition, this means that fuel labeled E85
will have an ethanol content between 70% and 85%.
Filling the fuel tank with fuel mixtures that do not meet
ASTM specications can affect driveability and could
cause the malfunction indicator lamp to come on.
5-8

Engine Oil Additives
Do not add anything to the oil. The recommended
oils with the starburst symbol that meet
GM Standard GM6094M are all you need for good
performance and engine protection.
Engine Oil Life System
When to Change Engine Oil
Your vehicle has a computer system that lets you know
when to change the engine oil and lter. This is based
on engine revolutions and engine temperature, and not
on mileage. Based on driving conditions, the mileage at
which an oil change will be indicated can vary
considerably. For the oil life system to work properly, you
must reset the system every time the oil is changed.
When the system has calculated that oil life has been
diminished, it will indicate that an oil change is
necessary. A CHANGE ENGINE OIL SOON message
will come on. SeeDIC Warnings and Messages on
page 3-63. Change the oil 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 oil life system might
not indicate that an oil change 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
people who will perform this work using genuine parts
and reset the system. It is also important to check the oil
regularly and keep it at the proper level.If the system is ever reset accidentally, you must
change the oil at 3,000 miles (5 000 km) since your last
oil change. Remember to reset the oil life system
whenever the oil is changed.
How to Reset the Engine Oil Life
System
The Engine Oil Life System calculates when to change
the engine oil and lter based on vehicle use. Whenever
the oil is changed, reset the system so it can calculate
when the next oil change is required. If a situation occurs
where you change the oil prior to a CHANGE ENGINE
OIL SOON message coming on, reset the system.
Always reset the engine oil life to 100% after every oil
change. It will not reset itself. To reset the Engine Oil
Life System:
1. Display the OIL LIFE REMAINING on the DIC. If
your vehicle does not have DIC buttons, the vehicle
must be in PARK (P) to access this display. SeeDIC
Operation and Displays (With DIC Buttons) on
page 3-55orDIC Operation and Displays
(Without DIC Buttons) on page 3-60.
2. Press and hold the SET/RESET button on the DIC,
or the trip odometer reset stem if your vehicle does
not have DIC buttons, for more than ve seconds.
The oil life will change to 100%.
If the CHANGE ENGINE OIL SOON message comes
back on when you start your vehicle, the Engine Oil Life
System has not reset. Repeat the procedure.
5-18