
Black plate (45,1)GMC Sierra Owner Manual - 2011
Instruments and Controls 5-45
Engine Oil Messages
CHANGE ENGINE OIL SOON
This message displays when the
engine oil needs to be changed.
When you change the engine oil,
be sure to reset the CHANGE
ENGINE OIL SOON message.
SeeEngine Oil Life System on
page 10‑11 for information on how
to reset the message. See Engine
Oil on page 10‑7 andScheduled
Maintenance on page 11‑2 for
more information.
ENGINE OIL HOT IDLE
ENGINE
This message displays when the
engine oil becomes hotter than the
normal operating temperature. Stop
and allow the vehicle to idle until it
cools down. See Engine Coolant
Temperature Gauge on page 5‑17.
OIL PRESSURE LOW STOP
ENGINE
Notice: If you drive the 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. See Engine Oil on
page 10‑7 for more information.
This message displays if low oil
pressure levels occur. 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 the oil as soon
as possible and have the vehicle
serviced by your dealer. See Engine
Oil on page 10‑7.
Engine Power Messages
ENGINE POWER IS REDUCED
This message displays and a
chime may sound when the cooling
system temperature gets too hot
and the engine further enters the
engine coolant protection mode.
See Engine Overheating on
page 10‑25 for more information.
This message also displays when
the vehicle's engine power is
reduced. Reduced engine power
can affect the vehicle's ability
to accelerate. If this message
is on, but there is no reduction
in performance, proceed to your
destination. The performance may
be reduced the next time the vehicle
is driven. The vehicle may be driven
at a reduced speed while this
message is on, but acceleration and
speed may be reduced. Anytime
this message stays on, the vehicle
should be taken to your dealer for
service as soon as possible.

Black plate (93,1)GMC Sierra Owner Manual - 2011
Driving and Operating 9-93
Passing
More passing distance is
needed when towing a trailer.
The combination will not accelerate
as quickly and is longer so it is
necessary to go much farther
beyond the passed vehicle before
returning to the lane.
Backing Up
Hold the bottom of the steering
wheel with one hand. To move the
trailer to the left, move that hand
to the left. To move the trailer to
the right, move your hand to the
right. Always back up slowly and,
if possible, have someone
guide you.
Making Turns
Notice:Making very sharp turns
while trailering could cause the
trailer to come in contact with
the vehicle. The vehicle could be
damaged. Avoid making very
sharp turns while trailering.
When turning with a trailer,
make wider turns than normal.
Do this so the trailer will not strike
soft shoulders, curbs, road signs,
trees, or other objects. Avoid jerky
or sudden maneuvers. Signal well
in advance.
If the trailer turn signal bulbs burn
out, the arrows on the instrument
panel will still flash for turns. It is
important to check occasionally to
be sure the trailer bulbs are still
working.
Driving on Grades
Reduce speed and shift to a
lower gear beforestarting down
a long or steep downgrade. If the
transmission is not shifted down,
the brakes might get hot and no
longer work well.
Vehicles can tow in D (Drive).
Shift the transmission to a lower
gear if the transmission shifts too
often under heavy loads and/or
hilly conditions.
The Tow/Haul Mode may be used
if the transmission shifts too often.
See Tow/Haul Mode on page 9‑51.
When towing at high altitude on
steep uphill grades, consider the
following: Engine coolant will boil
at a lower temperature than at
normal altitudes. If the engine is
turned off immediately after towing
at high altitude on steep uphill
grades, the vehicle may show
signs similar to engine overheating.

Black plate (10,1)GMC Sierra Owner Manual - 2011
10-10 Vehicle Care
Use of oils that do not meet the
dexos specification, however, may
result in reduced performance under
certain circumstances.
Viscosity Grade
SAE 5W-30 is the best viscosity
grade for the vehicle. Do not
use other viscosity oils such as
SAE 10W‐30, 10W‐40, or 20W-50.Cold Temperature Operation: In an
area of extreme cold, where the
temperature falls below−29°C
(−20°F), an SAE 0W-30 oil
should be used. An oil of this
viscosity grade will provide easier
cold starting for the engine at
extremely low temperatures.
When selecting an oil of the
appropriate viscosity grade, be
sure to always select an oil that
meets the required specification,
dexos. See “Specification” earlier
in this section for more information.

Black plate (11,1)GMC Sierra Owner Manual - 2011
Vehicle Care 10-11
Engine Oil Additives/Engine
Oil Flushes
Do not add anything to the oil.
The recommended oils with the
dexos specification and displaying
the dexos certification mark are all
that is needed for good performance
and engine protection.
Engine oil system flushes are not
recommended and could cause
engine damage not covered by
the vehicle warranty.
What to Do with Used Oil
Used engine oil contains certain
elements that can be unhealthy for
your skin and could even cause
cancer. Do not let used oil stay on
your skin for very long. Clean your
skin and nails with soap and water,
or a good hand cleaner. Wash or
properly dispose of clothing or rags
containing used engine oil. See the
manufacturer's warnings about the
use and disposal of oil products.
Used oil can be a threat to the
environment. If you change your
own oil, be sure to drain all the
oil from the filter before disposal.
Never dispose of oil by putting it
in the trash or pouring it on the
ground, into sewers, or into streams
or bodies of water. Recycle it by
taking it to a place that collects
used oil.
Engine Oil Life System
When to Change Engine Oil
This vehicle has a computer system
that indicates when to change the
engine oil and filter. This is based
on engine revolutions and engine
temperature, and not on mileage.
Based on driving conditions, the
mileage at which an oil change is
indicated can vary considerably.
For the oil life system to work
properly, the system must be reset
every time the oil is changed.
On some vehicles, when the system
has calculated that oil life has been
diminished, a CHANGE ENGINE
OIL SOON message comes on
to indicate that an oil change is
necessary. SeeEngine Oil
Messages on page 5‑45. Change
the oil as soon as possible within
the next 1 000 km (600 miles).

Black plate (13,1)GMC Sierra Owner Manual - 2011
Vehicle Care 10-13
Automatic
Transmission Fluid
(4-Speed Transmission)
When to Check and Change
Automatic Transmission Fluid
A good time to check the automatic
transmission fluid level is when the
engine oil is changed.
Change the fluid and filter at
the intervals listed inScheduled
Maintenance on page 11‑2 and be
sure to use the transmission fluid
listed in Recommended Fluids and
Lubricants on page 11‑8.
How to Check Automatic
Transmission Fluid
Because this operation can be a
little difficult, it may be best to have
this done at the dealer service
department.
If not taken to the dealer, be sure to
follow all the instructions here or a
false reading on the dipstick could
result.
Notice: Too much or too
little fluid can damage the
transmission. Too much can
mean that some of the fluid could
come out and fall on hot engine
parts or exhaust system parts,
starting a fire. Too little fluid
could cause the transmission
to overheat. Be sure to get an
accurate reading if checking
the transmission fluid. Wait at least 30 minutes before
checking the transmission fluid
level if you have been driving:.When outside temperatures are
above 32°C (90°F).
.At high speed for quite a while.
.In heavy traffic
—especially in
hot weather.
.While pulling a trailer.
To get the right reading, the fluid
should be at normal operating
temperature, which is 82°C to 93°C
(180°F to 200°F).
Get the vehicle warmed up by
driving about 24 km (15 miles) when
outside temperatures are above
10°C (50°F). If it is colder than 10°C
(50°F), drive the vehicle in 3 (Third)
until the engine temperature gauge
moves and then remains steady for
10 minutes.

Black plate (19,1)GMC Sierra Owner Manual - 2011
Vehicle Care 10-19
5. Safe operating level is within theHOT cross hatch band on the
dipstick. If the fluid level is not
within the HOT band, and the
transmission temperature is
between 71°C and 93°C (160°F
and 200°F), add or drain fluid as
necessary to bring the level into
the HOT band. If the fluid level
is low, add only enough fluid
to bring the level into the HOT
band. It does not take much
fluid, generally less than 0.5 L
(1 pint). Do not overfill.
6. If the fluid level is in the acceptable range, push the
dipstick back in all the way,
then flip the handle down to
lock the dipstick in place.
Consistency of Readings
Always check the fluid level at least
twice using the procedure described
previously. Consistency (repeatable
readings) is important to maintaining
proper fluid level. If readings are still
inconsistent, contact the dealer.
Engine Air Cleaner/Filter
If the vehicle has a diesel engine,
see “Pickup Models” under“Engine
Air Cleaner/Filter” in the Duramax
®
Diesel Supplement for the correct
inspection and replacement
procedures.
SeeEngine Compartment Overview
on page 10‑6 for the location of the
engine air cleaner/filter.
When to Inspect the Engine Air
Cleaner/Filter
Inspect the air cleaner/filter at
the scheduled maintenance
intervals and replace it at the first
oil change after each 80 000 km
(50,000 mi) interval. See Scheduled
Maintenance on page 11‑2 for more
information. If driving on dusty/dirty
conditions, inspect the filter at each
engine oil change.
How to Inspect the Engine Air
Cleaner/Filter
To inspect the air cleaner/filter,
remove the engine air cleaner/
filter from the vehicle by following
Steps 1 through 6. When the engine
air cleaner/filter is removed, lightly
shake it to release loose dust and
dirt. If the engine air cleaner/filter
remains covered with dirt, a new
filter is required. Never use
compressed air to clean the filter.

Black plate (22,1)GMC Sierra Owner Manual - 2011
10-22 Vehicle Care
Engine Coolant
The cooling system in the vehicle
is filled with DEX-COOL®engine
coolant. This coolant is designed to
remain in the vehicle for 5 years or
240 000 km (150,000 mi), whichever
occurs first.
The following explains the cooling
system and how to check and add
coolant when it is low. If there is a
problem with engine overheating,
see Engine Overheating on
page 10‑25.
What to Use
{WARNING
Adding only plain water or some
other liquid to the cooling system
can be dangerous. Plain water
and other liquids, can boil before
the proper coolant mixture will.
The coolant warning system is
set for the proper coolant mixture.
With plain water or the wrong
mixture, the engine could get too
hot but you would not get the
overheat warning. The engine
could catch fire and you or
others could be burned. Use a
50/50 mixture of clean, drinkable
water and DEX-COOL coolant. Use a 50/50 mixture of clean,
drinkable water and DEX-COOL
coolant. If using this mixture,
nothing else needs to be added.
This mixture:.Gives freezing protection down
to
−37°C (−34°F), outside
temperature
.Gives boiling protection
up to 129°C (265°F), engine
temperature
.Protects against rust and
corrosion
.Will not damage aluminum parts
.Helps keep the proper engine
temperature
Notice: If an improper coolant
mixture is used, the engine could
overheat and be badly damaged.
The repair cost would not be
covered by the vehicle warranty.
Too much water in the mixture
can freeze and crack the engine,
radiator, heater core, and other
parts.

Black plate (28,1)GMC Sierra Owner Manual - 2011
10-28 Vehicle Care
Overheated Engine
Protection
Operating Mode
If an overheated engine condition
exists and the ENGINE POWER IS
REDUCED message displays, an
overheat protection mode which
alternates firing groups of cylinders
helps to prevent engine damage.
In this mode, a loss in power and
engine performance will be noticed.
This operating mode allows the
vehicle to be driven to a safe
place in an emergency. Driving
extended km (mi) and/or towing a
trailer in the overheat protection
mode should be avoided.
Notice:After driving in the
overheated engine protection
operating mode, to avoid engine
damage, allow the engine to cool
before attempting any repair.
The engine oil will be severely
degraded. Repair the cause
of coolant loss, change the oil
and reset the oil life system.
See Engine Oil on page 10‑7.
Engine Fan
If the vehicle has a clutched engine
cooling fan, when the clutch is
engaged, the fan spins faster to
provide more air to cool the engine.
In most everyday driving conditions,
the fan is spinning slower and
the clutch is not fully engaged.
This improves fuel economy and
reduces fan noise. Under heavy
vehicle loading, trailer towing,
and/or high outside temperatures,
the fan speed increases as the
clutch more fully engages, so an
increase in fan noise may be heard.
This is normal and should not be
mistaken as the transmission
slipping or making extra shifts.
It is merely the cooling system
functioning properly. The fan will
slow down when additional cooling
is not required and the clutch
disengages. This fan noise may also be heard
when starting the engine. It will go
away as the fan clutch partially
disengages.
If the vehicle has electric cooling
fans, the fans may be heard
spinning at low speed during
most everyday driving. The fans
may turn off if no cooling is required.
Under heavy vehicle loading, trailer
towing, high outside temperatures,
or operation of the air conditioning
system, the fans may change to
high speed and an increase in fan
noise may be heard. This is normal
and indicates that the cooling
system is functioning properly.
The fans will change to low speed
when additional cooling is no
longer required.