
This light comes on briefly while starting the engine.
If it does not, have the vehicle serviced by your
dealer/retailer. If the system is working normally
the indicator light then goes off.
If the light comes on and stays on, it means that oil is
not flowing through the engine properly. The vehicle
could be low on oil and it might have some other system
problem.
Security Light
For information regarding
this light and the vehicle’s
security system, see
PASS-Key
®III+ Electronic
Immobilizer Operation
on page 2-17.
Cruise Control Light
The cruise control light
comes on whenever the
cruise control is set.
The light goes out when the cruise control is turned off.
SeeCruise Control on page 3-9for more information.
Highbeam On Light
This light comes on when
the high-beam headlamps
are in use.
SeeHeadlamp High/Low-Beam Changer on page 3-8
for more information.
3-39

SERVICE THEFT DETERRENT SYSTEM
This message displays when there is a problem with
the theft-deterrent system. The vehicle may or may
not restart so you may want to take the vehicle to
your dealer/retailer before turning off the engine.
SeePASS-Key
®III+ Electronic Immobilizer Operation
on page 2-17for more information.
SERVICE TIRE MONITOR SYSTEM
If your vehicle has the Tire Pressure Monitor System
(TPMS), this message displays if a part on the system is
not working properly. The tire pressure light also flashes
and then remains on during the same ignition cycle.
SeeTire Pressure Light on page 3-34. Several conditions
may cause this message to appear. SeeTire Pressure
Monitor Operation on page 5-65for more information.
If the warning comes on and stays on, there may be a
problem with the TPMS. See your dealer/retailer.
SERVICE TRACTION CONTROL
If your vehicle has StabiliTrak, this message displays
when there is a problem with the Traction Control
System (TCS). When this message displays, the system
will not limit wheel spin. Adjust your driving accordingly.
See your dealer/retailer for service. SeeStabiliTrak
®
System on page 4-5for more information.
SERVICE TRANSMISSION
This message displays when there is a problem with the
transmission. See your dealer/retailer for service.
SERVICE VEHICLE SOON
This message displays when a non-emissions related
malfunction occurs. Have the vehicle serviced by
your dealer/retailer as soon as possible.
STABILITRAK NOT READY
If your vehicle has StabiliTrak, this message may
display and the StabiliTrak indicator light on the
instrument panel cluster may be on after first driving the
vehicle and exceeding 20 mph (32 km/h) for 30 seconds.
The StabiliTrak system is not functional until the light
has turned off. SeeStabiliTrak
®System on page 4-5
for more information.
3-54

Press and hold the
StabiliTrak button located
on the instrument panel
for more than five seconds
to turn off StabiliTrak
and part of the traction
control system.
The StabiliTrak light comes
on the instrument panel
cluster when the system
is turned off or requires
service.
For more information, seeStabiliTrak
®Indicator Light
on page 3-33.For your safety, the system can only be disabled when
the vehicle speed is less than 20 mph (32 km/h).
Three chimes will be heard and the StabiliTrak light
comes on.
To turn on the StabiliTrak system, press the StabiliTrak
button again. StabiliTrak will automatically turn back on
when the vehicle speed exceeds 20 mph (32 km/h).
One chime is heard and the StabiliTrak light will turn off.
When the StabiliTrak system has been turned off,
system noises may still be heard as a result of the
brake-traction control coming on.
It is recommended to leave the system on for normal
driving conditions, but it may be necessary to turn
the system off if the vehicle is stuck in sand, mud, ice or
snow, and you want to “rock” the vehicle to attempt to
free it. SeeIf Your Vehicle is Stuck in Sand, Mud, Ice, or
Snow on page 4-18.
4-6

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 Speci cations
At a minimum, gasoline should meet ASTM
specification 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.
California Fuel
If the vehicle is certified to meet California Emissions
Standards, it is designed to operate on fuels that meet
California specifications. See the underhood emission
control label. If this fuel is not available in states adopting
California emissions standards, the vehicle will operate
satisfactorily on fuels meeting federal specifications, but
emission control system performance might be affected.
The malfunction indicator lamp could turn on and the
vehicle might fail a smog-check test. SeeMalfunction
Indicator Lamp on page 3-34. 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 the vehicle warranty.
5-6

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 the vehicle experiences
problems due to dirty injectors or valves, look for gasoline
that 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 specifications 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:This 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 the
vehicle 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 Identification Number (VIN)
shows the code letter or number that identifies the
vehicle’s engine. The VIN is at the top left of the
instrument panel. SeeVehicle Identification
Number (VIN) on page 5-104.
If the vehicle has the 5.3L V8 engine (VIN Code 4) and
the N15 flexible fuel option, you can use either unleaded
gasoline or ethanol fuel containing up to 85% ethanol
(E85). SeeFuel on page 5-5. For the 5.3L V8 engine
(VIN Code 4) without the N15 option and all other
gasoline engines, use only the unleaded gasoline
described underGasoline Octane on page 5-6.
Only vehicles that have the 5.3L V8 engine
(VIN Code 4) and the N15 flexible fuel option 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 findE85 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 Specification
D 5798. By definition, 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 specifications can affect driveability and could
cause the malfunction indicator lamp to come on.
To ensure quick starts in the wintertime, the E85 fuel
must be formulated properly for your climate according to
ASTM specification D 5798. If you have trouble starting
on E85, it could be because the E85 fuel is not properly
formulated for your climate. If this happens, switching to
gasoline or adding gasoline to the fuel tank can improve
starting. For good starting and heater efficiency below
32°F (0°C), the fuel mix in the fuel tank should contain
no more than 70% ethanol. It is best not to alternate
repeatedly between gasoline and E85. If you do switch
fuels, it is recommended that you add as much fuel as
possible — do not add less than three gallons (11 L)
when refueling. You should drive the vehicle immediately
after refueling for at least seven miles (11 km) to allow the
vehicle to adapt to the change in ethanol concentration.
5-8

Radiator Pressure Cap
The radiator pressure cap is located near the center of
the engine compartment. SeeEngine Compartment
Overview on page 5-14for more information on location.
Notice:If the pressure cap is not tightly installed,
coolant loss and possible engine damage may
occur. Be sure the cap is properly and tightly
secured.
Engine Overheating
If your vehicle has the DURAMAX Diesel engine, see
the DURAMAX Diesel manual for more information.
The vehicle has an indicator to warn of engine
overheating.
You will find an engine coolant temperature gage on
your vehicle’s instrument panel. SeeEngine Coolant
Temperature Gage on page 3-33for more information.You may decide not to lift the hood when this warning
appears, but instead get service help right away.
SeeRoadside Assistance Program on page 7-7.
If you do decide to lift the hood, make sure the vehicle
is parked on a level surface.
Then check to see if the engine cooling fans are
running. If the engine is overheating, both fans should
be running. If they are not, do not continue to run
the engine and have the vehicle serviced.
See if the engine cooling fan speed increases when idle
speed is doubled by pushing the accelerator pedal down.
If it does not, your vehicle needs service. Turn off the
engine.
Notice:Engine damage from running the engine
without coolant is not covered by the warranty.
Notice:If the engine catches re because of being
driven with no coolant, your vehicle can be badly
damaged. The costly repairs would not be covered
by the vehicle warranty.
5-31

Brake Wear
This vehicle has disc brakes. Disc brake pads have
built-in wear indicators that make a high-pitched warning
sound when the brake pads are worn and new pads
are needed. The sound can come and go or be heard
all the time the vehicle is moving, except when applying
the brake pedal firmly.
{CAUTION:
The brake wear warning sound means that soon
the brakes will not work well. That could lead to an
accident. When the brake wear warning sound is
heard, have the vehicle serviced.
Notice:Continuing to drive with worn-out brake
pads could result in costly brake repair.Some driving conditions or climates can cause a brake
squeal when the brakes are first applied or lightly
applied. This does not mean something is wrong
with the brakes.
Properly torqued wheel nuts are necessary to help
prevent brake pulsation. When tires are rotated, inspect
brake pads for wear and evenly tighten wheel nuts
in the proper sequence to torque specifications
inCapacities and Specifications on page 5-111.
Brake linings should always be replaced as complete
axle sets.Brake Pedal Travel
See your dealer/retailer if the brake pedal does not
return to normal height, or if there is a rapid increase in
pedal travel. This could be a sign that brake service
might be required.
Brake Adjustment
Every brake stop, the brakes adjust for wear.
5-38