
When the Light is On Steady
This indicates that one or more of the tires are
significantly underinflated.
A tire pressure message in the Driver Information
Center (DIC), can accompany the light. SeeDriver
Information Center (DIC) on page 4-37for more
information. Stop and check the tires as soon as it is
safe to do so. If underinflated, inflate to the proper
pressure. SeeIn ation - Tire Pressure on page 6-63for
more information.
When the Light Flashes First and Then is
On Steady
This indicates that there may be a problem with the Tire
Pressure Monitor System. The light flashes for about
a minute and stays on steady for the remainder of
the ignition cycle. This sequence repeats with every
ignition cycle. SeeTire Pressure Monitor Operation on
page 6-66for more information.
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
is 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.
4-31

Oil Pressure Light
{WARNING:
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.
Security Light
For information regarding
this light and the vehicle’s
security system, see
PASS-Key
®III+ Electronic
Immobilizer Operation
on page 3-20.
4-35

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 5-5for 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 32 km/h (20 mph) for 30 seconds.The StabiliTrak system is not functional until the light
has turned off. SeeStabiliTrak
®System on page 5-5for
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 5-16. To turn
the StabiliTrak system on or off, seeStabiliTrak
®
System on page 5-5.
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 4-28.
4-50

•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 turns off as soon as the conditions that
caused the message to be displayed are no longer
present.
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 4-31.Reinstall the fuel cap fully. SeeFilling the Tank on
page 6-10. 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 4-38for more
information. The tire positions must be re-learned after
rotating the tires or after replacing a tire or sensor.
SeeTire Inspection and Rotation on page 6-69,
Tire Pressure Monitor System on page 6-65, and
In ation - Tire Pressure on page 6-63for 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 5-5for more information.
4-51

Using ABS
Do not pump the brakes. Just hold the brake pedal
down firmly and let antilock work. The brakes might
vibrate or some noise might be heard, but this is normal.
Braking in Emergencies
ABS allows the driver to steer and brake at the same
time. In many emergencies, steering can help more than
even the very best braking.
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 shouldinitialize 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 4-29.
5-5

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.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 Identi cation Number
(VIN) on page 6-103.
If the vehicle has the 4.8L V8 engine (VIN Code A), the
5.3L V8 (VIN Code 4), or the 6.0L V8 engine (VIN
Code G) and the N15 flexible fuel option, you can use
either unleaded gasoline or ethanol fuel containing up to
85% ethanol (E85). SeeFuel on page 6-5. For all
other gasoline engines, use only the unleaded gasoline
described underGasoline Octane on page 6-6.
Only vehicles that have the 4.8L V8 engine (VIN Code A),
the 5.3L V8 (VIN Code 4), or the 6.0L V8 engine (VIN
Code G) 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%.
6-8

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 4-30for 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 8-6.
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.
If Steam Is Coming From The Engine
Compartment
{WARNING:
Steam from an overheated engine can burn you
badly, even if you just open the hood. Stay away
from the engine if you see or hear steam coming
from it. Just turn it off and get everyone away from
the vehicle until it cools down. Wait until there is no
sign of steam or coolant before you open the hood.
If you keep driving when your engine is overheated,
the liquids in it can catch fire. You or others could
be badly burned. Stop your engine if it overheats,
and get out of the vehicle until the engine is cool.
6-33

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.
{WARNING:
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 in
Capacities and Speci cations on page 6-110.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.
Replacing Brake System Parts
The braking system on a vehicle is complex. Its many
parts have to be of top quality and work well together if
the vehicle is to have really good braking. The vehicle
was designed and tested with top-quality brake parts.
When parts of the braking system are replaced — for
example, when the brake linings wear down and new
ones are installed — be sure to get new approved
replacement parts. If this is not done, the brakes might
not work properly. For example, if someone puts in brake
linings that are wrong for the vehicle, the balance
between the front and rear brakes can change — for the
worse. The braking performance expected can change in
many other ways if the wrong replacement brake parts
are installed.
6-39