Malfunction Indicator Lamp
Check Engine Light
A computer system called OBD II (On-Board
Diagnostics-Second Generation) monitors operation
of the fuel, ignition, and emission control systems.
It ensures that emissions are at acceptable levels for
the life of the vehicle, helping to produce a cleaner
environment.
This light should come on
when the ignition is on, but
the engine is not running,
as a check to show it
working. If it does not, have
the vehicle serviced by your
dealer/retailer.If the check engine light comes on and stays on, while
the engine is running, this indicates that there is an
OBD II problem and service is required.
Malfunctions often are indicated by the system before any
problem is apparent. Being aware of the light can prevent
more serious damage to the vehicle. This system assists
the service technician in correctly diagnosing any
malfunction.
Notice:If the vehicle is continually driven with this
light on, after a while, the emission controls might
not work as well, the vehicle’s fuel economy might
not be as good, and the engine might not run as
smoothly. This could lead to costly repairs that
might not be covered by the vehicle warranty.
3-36
Oil Pressure Light
{CAUTION:
Do not keep driving if the oil pressure is low. The
engine can become so hot that it catches fire.
Someone could be burned. Check the oil as soon
as possible and have the vehicle serviced.Notice:Lack of proper engine oil maintenance
can damage the engine. The repairs would not be
covered by the vehicle warranty. Always follow
the maintenance schedule in this manual for
changing engine oil.
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.
3-40
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 4-6for
more information.
STABILITRAK OFF
If your vehicle has StabiliTrak, this message displays
when you turn off StabiliTrak, or when the stability control
has been automatically disabled. To limit wheel spin and
realize the full benefits of the stability enhancement
system, you should normally leave StabiliTrak on.
However, you should turn StabiliTrak off if your vehicle
gets stuck in sand, mud, ice, or snow and you want to
rock your vehicle to attempt to free it, or if you are driving
in extreme off-road conditions and require more wheel
spin. SeeIf Your Vehicle is Stuck in Sand, Mud, Ice, or
Snow on page 4-17. To turn the StabiliTrak system on or
off, seeStabiliTrak
®System on page 4-6.There are several conditions that can cause this
message to appear.
•One condition is overheating, which could occur if
StabiliTrak activates continuously for an extended
period of time.
•The message also displays if the brake system
warning light is on. SeeBrake System Warning
Light on page 3-33.
•The message could display if the stability system
takes longer than usual to complete its diagnostic
checks due to driving conditions.
•The message displays if an engine or vehicle
related problem has been detected and the vehicle
needs service. See your dealer/retailer.
•The message also displays if the vehicle is shifted
into 4LO.
The message turns off as soon as the conditions that
caused the message to be displayed are no longer
present.
3-57
STARTING DISABLED SERVICE
THROTTLE
This message displays if the starting of the engine is
disabled due to the electronic throttle control system.
Have your vehicle serviced by your dealer/retailer
immediately.
This message only appears while the ignition is in
ON/RUN, and will not disappear until the problem is
resolved.
This message cannot be acknowledged.
TIGHTEN GAS CAP
This message may display and a chime may be heard
along with the check engine light on the instrument
panel cluster if the vehicle’s fuel cap is not tightened
properly. SeeMalfunction Indicator Lamp on page 3-36.
Reinstall the fuel cap fully. SeeFilling the Tank on
page 5-10. The diagnostic system can determine if the
fuel cap has been left off or improperly installed. A
loose or missing fuel cap allows fuel to evaporate into
the atmosphere. A few driving trips with the cap properly
installed should turn this light and message off.
TIRE LEARNING ACTIVE
If your vehicle has the Tire Pressure Monitor System
(TPMS), this message displays when the system is
re-learning the tire positions on your vehicle. SeeDIC
Operation and Displays on page 3-43for more
information. The tire positions must be re-learned after
rotating the tires or after replacing a tire or sensor. See
Tire Inspection and Rotation on page 5-69,Tire Pressure
Monitor System on page 5-64, andInflation - Tire
Pressure on page 5-62for more information.
TRACTION CONTROL OFF
If your vehicle has StabiliTrak, this message displays
when the Traction Control System (TCS) is turned
off. Adjust your driving accordingly. SeeStabiliTrak
®
System on page 4-6for more information.
TRANSMISSION HOT IDLE ENGINE
Notice:If you drive your vehicle while the
transmission uid is overheating and the
transmission temperature warning is displayed on
the instrument panel cluster and/or DIC, you
can damage the transmission. This could lead to
costly repairs that would not be covered by
your warranty. Do not drive your vehicle with
overheated transmission uid or while the
transmission temperature warning is displayed.
3-58
StabiliTrak®System
The vehicle may have a vehicle stability enhancement
system called StabiliTrak. It is an advanced computer
controlled system that assists the driver with directional
control of the vehicle in difficult driving conditions.
StabiliTrak activates when the computer senses a
discrepancy between the intended path and the direction
the vehicle is actually traveling. StabiliTrak selectively
applies braking pressure at any one of the vehicle’s
brakes to assist the driver with keeping the vehicle on
the intended path.
When the vehicle is started and begins to move, the
system performs several diagnostic checks to insure
there are no problems. The system may be heard or felt
while it is working. This is normal and does not mean
there is a problem with the vehicle. The system should
initialize before the vehicle reaches 20 mph (32 km/h). In
some cases, it may take approximately 2 miles (3.2 km)
of driving before the system initializes.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 3-34.
4-6
If the vehicle has the 5.3L V8 engine (VIN Code 4) and
the N15 flexible fuel option, you can use either regular
unleaded gasoline or ethanol fuel containing up to 85%
ethanol (E85). SeeFuel E85 (85% Ethanol) on page 5-8.
For the 5.3L V8 engine (VIN Code 4) without the N15
option and 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 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 5-7
for 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 3-36. 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 5-103.
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 find
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 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.
5-8