2005 CHEVROLET SILVERADO service

At approximately 265°F (130°C), the driver information
center will display a TRANSMISSION HOT message
and the transmission will enter a transmission protection
mode. When the transmission enters the protection
mode, you may notice a change in the transmission
shifting patterns. The transmission will return to normal
shifting patterns when the transmission uid temperature
falls below 260°F (127°C).
SeeDriver Information Center (DIC) on page 3-50for
further information.
If your vehicle has an Allison transmission, and the uid
reaches temperatures of approximately 275°F (135°C)
or greater, the driver information center will display
a TRANS HOT IDLE ENGINE warning message and
a chime will sound until the temperature falls below
265°F (129°C). Pull the vehicle off the roadway when
it is safe to do so. Set the parking brake, place the
transmission in PARK (P) and allow the engine to
idle until the transmission temperature falls below
265°F (129°C). If the transmission continues to operate
above 265°F (130°C), contact your nearest dealer or
the GM Roadside Assistance Center. SeeRoadside
Assistance Program on page 7-6.Notice:If you drive your vehicle with the
transmission temperature gage above normal
operating range, you can damage the transmission.
This could lead to costly repairs that would not
be covered by your warranty. Do not drive your
vehicle while the transmission temperature gage
reading is above normal. See your dealer for service.
The following situations can cause the transmission to
operate at higher temperatures:
Towing a trailer
Hot outside air temperatures
Vehicle overloading
Hauling a large or heavy load
Low transmission uid level
High transmission uid level
Restricted air ow to the radiator and the auxiliary
transmission oil cooler (if equipped).
A temporary solution to hotter transmission operating
temperatures may be to let the transmission cool down.
If the transmission is operated at higher temperatures
on a frequent basis, seeScheduled Maintenance
(Gasoline Engine) on page 6-4for the proper
transmission maintenance intervals.
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Malfunction Indicator Lamp
Check Engine Light
Your vehicle is equipped
with a computer which
monitors operation of the
fuel, ignition, and emission
control systems.
This system is called OBD II (On-Board
Diagnostics-Second Generation) and is intended to
assure that emissions are at acceptable levels for the
life of the vehicle, helping to produce a cleaner
environment. The check engine light comes on to
indicate that there is a problem and service is required.
Malfunctions often will be indicated by the system
before any problem is apparent. This may prevent more
serious damage to your vehicle. This system is also
designed to assist your service technician in correctly
diagnosing any malfunction.
Notice:If you keep driving your vehicle with this
light on, after awhile, your emission controls may not
work as well, your fuel economy may not be as good,
and your engine may not run as smoothly. This could
lead to costly repairs that may not be covered by
your warranty.Notice:Modications made to the engine,
transmission, exhaust, intake, or fuel system of
your vehicle or the replacement of the original tires
with other than those of the same Tire Performance
Criteria (TPC) can affect your vehicle’s emission
controls and may cause this light to come on.
Modications to these systems could lead to costly
repairs not covered by your warranty. This may
also result in a failure to pass a required Emission
Inspection/Maintenance test.
This light should come on, as a check to show you it is
working, when the ignition is on and the engine is
not running. If the light does not come on, have it
repaired. This light will also come on during a
malfunction in one of two ways:
Light Flashing— A misre condition has been
detected. A misre increases vehicle emissions
and may damage the emission control system on
your vehicle. Diagnosis and service may be
required.
Light On Steady— An emission control system
malfunction has been detected on your vehicle.
Diagnosis and service may be required.
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If the Light is Flashing
The following may prevent more serious damage to
your vehicle:
Reducing vehicle speed
Avoiding hard accelerations
Avoiding steep uphill grades
If you are towing a trailer, reduce the amount of
cargo being hauled as soon as it is possible
If the light stops ashing and remains on steady,
see “If the Light Is On Steady” following.
If the light continues to ash, when it is safe to do
so, stop the vehicle. Find a safe place to park your
vehicle. Turn the key off, wait at least 10 seconds and
restart the engine. If the light remains on steady, see
“If the Light Is On Steady” following. If the light is
still ashing, follow the previous steps, and see your
dealer for service as soon as possible.
If the Light Is On Steady
You may be able to correct the emission system
malfunction by considering the following:
Did you recently put fuel into your vehicle?
If so, reinstall the fuel cap, making sure to fully
install the cap. 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 will allow fuel to evaporate
into the atmosphere. A few driving trips with the cap
properly installed should turn the light off.
Did you just drive through a deep puddle of water?
If so, your electrical system may be wet. The condition
will usually be corrected when the electrical system
dries out. A few driving trips should turn the light off.
Have you recently changed brands of fuel?
If so, be sure to fuel your vehicle with quality fuel. See
Gasoline Octane on page 5-6. Poor fuel quality will
cause your engine not to run as efficiently as designed.
You may notice this as stalling after start-up, stalling
when you put the vehicle into gear, misring, hesitation
on acceleration, or stumbling on acceleration. (These
conditions may go away once the engine is warmed up.)
This will be detected by the system and cause the
light to turn on.
If you experience one or more of these conditions,
change the fuel brand you use. It will require at least
one full tank of the proper fuel to turn the light off.
If none of the above steps have made the light turn off,
your dealer can check the vehicle. Your dealer has
the proper test equipment and diagnostic tools to x
any mechanical or electrical problems that may
have developed.
3-45

A reading in the low pressure zone may be caused by
a dangerously low oil level or some other problem
causing low oil pressure. Check your oil as soon as
possible. See “OIL PRESSURE LOW” underDIC
Warnings and Messages on page 3-54andEngine Oil
(Gasoline Engine) on page 5-20.
{CAUTION:
Do not keep driving if the oil pressure is low.
If you do, your engine can become so hot that
it catches re. You or others could be burned.
Check your oil as soon as possible and have
your vehicle serviced.
Notice:Lack of proper engine oil maintenance
may damage the engine. The repairs would not
be covered by your warranty. Always follow
the maintenance schedule in this manual for
changing engine oil.
Security Light
This light ashes when the
vehicle security system is
activated.
Cruise Control Light
This light comes on
whenever you set your
cruise control.
The light will go out when the cruise control is turned
off. SeeCruise Control on page 3-10for more
information.
3-47

LOW COOLANT LEVEL
If your vehicle is equipped with a low coolant level
sensor, this message will appear on the DIC if
the engine coolant level is low. Adding coolant will
clear the message. SeeCooling System on page 5-40.
Pressing any of the four DIC buttons, if equipped,
will acknowledge the message and clear it from the
DIC display. If your vehicle is not equipped with the
four DIC buttons, pressing the trip odometer reset stem
will acknowledge the message and clear it from the
DIC display.
Notice:Engine damage from running your engine
without coolant is not covered by your warranty.
See “Overheated Engine Protection Operating
Mode” in the Index for information on driving to
a safe place in an emergency.
OIL LIFE RESET
This message will appear on the DIC for about
10 seconds after resetting the change engine oil
message. See “Engine Oil Life System” underDIC
Operation and Displays on page 3-51andEngine Oil
(Gasoline Engine) on page 5-20for more information.
OIL PRESSURE LOW
If low oil pressure levels occur, this message will be
displayed on the DIC and a chime will sound. Stop the
vehicle as soon as safely possible and do not operate
it until the cause of the low oil pressure has been
corrected. Check your oil as soon as possible and have
your vehicle serviced by your GM dealer. SeeEngine
Oil (Gasoline Engine) on page 5-20.
Notice:If you drive your vehicle while the engine
oil pressure is low, severe engine damage may
occur. If a low oil pressure warning appears on the
Driver Information Center (DIC), stop the vehicle
as soon as possible. Do not drive the vehicle until
the cause of the low oil pressure is corrected.
SeeEngine Oil (Gasoline Engine) on page 5-20for
more information.
PASSENGER DOOR AJAR
If the passenger’s door is not fully closed, this message
will appear on the display and you will hear a chime.
Stop and turn off the vehicle, check the door for
obstacles, and close the door again. Check to see if
the message still appears on the DIC. Pressing any of
the four DIC buttons, if equipped, will acknowledge
the message and clear it from the DIC display. If your
vehicle is not equipped with the four DIC buttons,
pressing the trip odometer reset stem will acknowledge
the message and clear it from the DIC display.
3-58

RANGE SHIFT INHIBITED
(Allison Transmission®Only)
If the transmission is unable to shift into a selected
gear, this message will appear on the DIC. The
electronic shift position indicator on the instrument panel
cluster may blink when this occurs. To make the
vehicle shift to the requested gear, you may have to
shift back to PARK (P) or NEUTRAL (N) and re-select
the desired gear.
REDUCED ENGINE POWER
This message is displayed when the cooling system
temperature gets too hot and the engine further enters
the engine coolant protection mode.
SeeEngine Overheating on page 5-38for additional
information.
RIGHT REAR DOOR AJAR (Crew Cab)
If the passenger’s side rear door is not fully closed,
this message will appear on the display and you
will hear a chime. Stop and turn off the vehicle, check
the door for obstacles, and close the door again.
Check to see if the message still appears on the DIC.
Pressing any of the four DIC buttons, if equipped,
will acknowledge the message and clear it from the
DIC display. If your vehicle is not equipped with the
four DIC buttons, pressing the trip odometer reset stem
will acknowledge the message and clear it from the
DIC display.
SERVICE 4WD (Four-Wheel-Drive)
If a problem occurs with the four-wheel-drive system,
this message will appear on the DIC. If this message
appears, stop as soon as possible and turn off the
vehicle. Restart the vehicle and check for the message
on the DIC display. If the message is still displayed
or appears again when you begin driving, the
four-wheel-drive system needs service. See your
GM dealer.
SERVICE 4 WHEEL STEER
If a problem occurs with the four-wheel steer system,
this message will appear on the DIC. If this message
appears, stop as soon as possible and turn off the
vehicle. Restart the vehicle and check for the message
on the DIC display. If the message is still displayed
or appears again when you begin driving, the four-wheel
steer system needs service. See your GM dealer. See
QUADRASTEER™ on page 4-14for more information.
Pressing any of the four DIC buttons, if equipped,
will acknowledge the message and clear it from the
DIC display. If your vehicle is not equipped with the
four DIC buttons, pressing the trip odometer reset stem
will acknowledge the message and clear it from the
DIC display.
3-59

SERVICE AIR BAG
If there is a problem with the airbag system, this
message will be displayed on the DIC. Have your
GM dealer inspect the system for problems. SeeAirbag
Readiness Light on page 3-34andAirbag System on
page 1-63for more information. Pressing any of the
four DIC buttons, if equipped, will acknowledge
the message and clear it from the DIC display. If your
vehicle is not equipped with the four DIC buttons,
pressing the trip odometer reset stem will acknowledge
the message and clear it from the DIC display.
SERVICE BRAKE BOOSTER
If your vehicle has vacuum assist power brakes, this
message will be displayed on the DIC when there is a
problem with the Supplemental Brake Assist system.
If the message is displayed immediately after starting
the vehicle or the message appears while driving,
your Supplemental Brake Assist system needs service.
See your GM dealer. SeeBrake System Warning
Light on page 3-40for additional information.
{CAUTION:
Your brake system may not be working
properly if the SERVICE BRAKE BOOSTER
message is displayed.
If the brake system warning light is also on,
you should have the vehicle towed for service.
SeeBrake System Warning Light on page 3-40.
If the brake system warning light is not on,
you still have brakes, but the supplemental
brake assist system on vehicles with rear disc
brakes may not operate properly. In the event
of a vacuum loss, you may not have vacuum
power assist for braking. The brake pedal
will be harder to push and it will take longer
to stop. If you continue to drive with this
message displayed it can lead to a crash.
Have the brake system serviced as soon as
possible.
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SERVICE BRAKE SYSTEM
If there is a problem with the brake system, this
message will be displayed on the DIC. If this message
appears, stop as soon as possible and turn off the
vehicle. Restart the vehicle and check for the message
on the DIC display. If the message is still displayed
or appears again when you begin driving, the brake
system needs service. See your GM dealer.
SERVICE CHARGING SYSTEM
On some vehicles, if there is a problem with the battery
charging system, this message will appear on the
DIC. Under certain conditions, the battery warning light
may also turn on in the instrument panel cluster.
SeeBattery Warning Light on page 3-38. The battery
will not be charging at an optimal rate and the vehicle
will lose the ability to enter the fuel economy mode.
The vehicle is safe to drive, however you should have
the electrical system checked by your GM dealer.
Pressing any of the four DIC buttons, if equipped,
will acknowledge the message and clear it from the
DIC display. If your vehicle is not equipped with the
four DIC buttons, pressing the trip odometer reset stem
will acknowledge the message and clear it from the
DIC display.
SERVICE RIDE CONTROL
If a problem occurs with the suspension system, this
message will appear on the DIC. If this message
appears, stop and turn off the vehicle. Restart the
vehicle and check for the message on the DIC display.
If this message is still displayed or appears again
when you begin driving, the air suspension system
needs service. See your GM dealer.
TIGHTEN FUEL CAP
If the vehicle’s fuel cap is not tightened properly, this
message may appear along with the check engine
light on the instrument panel cluster. SeeMalfunction
Indicator Lamp on page 3-44. 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
will allow fuel to evaporate into the atmosphere.
A few driving trips with the cap properly installed
should turn this light and message off.
TRACTION ACTIVE
When the traction control system had detected that
any of the vehicle’s wheels are slipping, the traction
control system will activate and this message will appear
on the DIC. SeeTraction Assist System (TAS) on
page 4-8for more information.
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