
Black plate (72,1)GMC Sierra Owner Manual - 2013 - crc - 8/14/12
9-72 Driving and Operating
combination moving and then apply
the trailer brake controller by hand
to be sure the brakes work.
During the trip, check occasionally
to be sure that the load is secure
and the lamps and any trailer
brakes still work.
Following Distance
Stay at least twice as far behind the
vehicle ahead as you would when
driving the vehicle without a trailer.
This can help to avoid heavy
braking and sudden turns.
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 tothe 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
cluster 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 before starting 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 9‑37.
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. To avoid this,
let the engine run while parked,
preferably on level ground, with the
automatic transmission in P (Park)

Black plate (18,1)GMC Sierra Owner Manual - 2013 - crc - 8/14/12
10-18 Vehicle Care
WARNING (Continued)
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 improper coolant
mixture, inhibitors, or additives
are used in the vehicle cooling
system, the engine could
overheat and be damaged. Too
much water in the mixture can
freeze and crack engine cooling
parts. The repairs would not be
covered by the warranty. Use only
the proper mixture of engine
coolant for the cooling system.
See Recommended Fluids and
Lubricants on page 11‑12.
Never dispose of engine coolant by
putting it in the trash, pouring it on
the ground, or into sewers, streams,
or bodies of water. Have the coolant
changed by an authorized service
center, familiar with legal
requirements regarding used
coolant disposal. This will help
protect the environment and your
health.Checking Coolant
The coolant surge tank is located in
the engine compartment on the
passenger side of the vehicle. See
Engine Compartment Overview on
page 10‑5 for more information on
location.
The vehicle must be on a level
surface when checking the coolant
level.
Check to see if coolant is visible in
the coolant surge tank. If the coolant
inside the coolant surge tank is
boiling, do not do anything else until
it cools down. If coolant is visible
but the coolant level is not at or
above the FULL COLD mark, add a
50/50 mixture of clean, drinkable
water and DEX-COOL coolant at the
coolant surge tank, but be sure the
cooling system is cool before this
is done.

Black plate (20,1)GMC Sierra Owner Manual - 2013 - crc - 8/14/12
10-20 Vehicle Care
3. Fill the coolant surge tank withthe proper mixture to the FULL
COLD mark.
4. With the coolant surge tank pressure cap off, start the
engine and let it run until the
engine coolant temperature
gauge indicates approximately
90°C (195°F).
By this time, the coolant level
inside the coolant surge tank
may be lower. If the level is
lower, add more of the proper mixture to the coolant surge tank
until the level reaches the FULL
COLD mark.
5. Replace the pressure cap tightly.
6. Verify coolant level after the engine is shut off and the
coolant is cold. If necessary,
repeat coolant fill procedure
Steps 1 through 6.
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 the vehicle has the Duramax®
Diesel engine, see the Duramax
Diesel Supplement for more
information.
The vehicle has several indicators
to warn of engine overheating.
There is a coolant temperature
gauge on the vehicle's instrument
panel. See Engine Coolant
Temperature Gauge on page 5‑15. In addition, there are ENGINE
OVERHEATED STOP ENGINE,
ENGINE OVERHEATED IDLE
ENGINE, and ENGINE POWER IS
REDUCED messages in the Driver
Information Center (DIC) on the
instrument panel. See
Engine
Cooling System Messages on
page 5‑39 andEngine Power
Messages on page 5‑40.
If the decision is made not to lift the
hood when this warning appears,
get service help right away. See
Roadside Assistance Program
(Mexico) on page 13‑7 orRoadside
Assistance Program (U.S. and
Canada) on page 13‑11.
If the decision is made 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.

Black plate (21,1)GMC Sierra Owner Manual - 2013 - crc - 8/14/12
Vehicle Care 10-21
Notice:Running the engine
without coolant may cause
damage or a fire. Vehicle damage
would not be covered by the
warranty. See Overheated Engine
Protection Operating Mode on
page 10‑22 for information on
driving to a safe place in an
emergency.
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. 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.
(Continued)
WARNING (Continued)
If you keep driving when the
vehicles engine is overheated,
the liquids in it can catch fire. You
or others could be badly burned.
Stop the engine if it overheats,
and get out of the vehicle until the
engine is cool.
SeeOverheated Engine
Protection Operating Mode on
page 10‑22 for information on
driving to a safe place in an
emergency.
If No Steam is Coming from
the Engine Compartment
The ENGINE OVERHEATED STOP
ENGINE or the ENGINE
OVERHEATED IDLE ENGINE
message, along with a low coolant
condition, can indicate a serious
problem. If there is an engine overheat
warning, but no steam is seen or
heard, the problem may not be too
serious. Sometimes the engine can
get a little too hot when the vehicle:
.Climbs a long hill on a hot day
.Stops after high-speed driving
.Idles for long periods in traffic
.Tows a trailer; see
Trailer Towing
on page 9‑73.
If the ENGINE OVERHEATED
STOP ENGINE or the ENGINE
OVERHEATED IDLE ENGINE
message appears with no sign of
steam, try this for a minute or so:
1. Turn the air conditioning off.
2. Turn the heater on to the highest temperature and to the highest
fan speed. Open the windows as
necessary.
3. If stopped in a traffic jam, apply the brake, shift to N (Neutral);
otherwise, shift to the highest
gear while driving —D (Drive) or
3 (Third).

Black plate (22,1)GMC Sierra Owner Manual - 2013 - crc - 8/14/12
10-22 Vehicle Care
If the temperature overheat gauge is
no longer in the overheat zone or an
overheat warning no longer
displays, the vehicle can be driven.
Continue to drive the vehicle slowly
for about 10 minutes. Keep a safe
vehicle distance from the vehicle in
front. If the warning does not come
back on, continue to drive normally.
If the warning continues, pull over,
stop, and park the vehicle
right away.
If there is no sign of steam, idle the
engine for five minutes while
parked. If the warning is still
displayed, turn off the engine until it
cools down. Also, see“Overheated
Engine Protection Operating Mode”
later in this section.
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 10‑6.
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,

Black plate (3,1)GMC Sierra Owner Manual - 2013 - crc - 8/14/12
INDEX i-3
Charging System Light . . . . . . . . 5-20
CheckEngine Light . . . . . . . . . . . . . . . . . . 5-21
IgnitionTransmission Lock . . . . . . . . 10-32
Child Restraints Infants and Young
Children . . . . . . . . . . . . . . . . . . . . . 3-40
Lower Anchors and Tethers for Children . . . . . . . . . 3-45
Older Children . . . . . . . . . . . . . . . . 3-38
Securing . . . . . . . . . . 3-54, 3-56, 3-57
Systems . . . . . . . . . . . . . . . . . . . . . . 3-42
Cigarette Lighter . . . . . . . . . . . . . . . . 5-9
Circuit Breakers . . . . . . . . . . . . . . 10-39
Cleaning Exterior Care . . . . . . . . . . . . . . . 10-91
Interior Care . . . . . . . . . . . . . . . . 10-94
Climate Control Systems . . . 8-1, 8-4 Air Conditioning . . . . . . . . . . 8-1, 8-4
Dual Automatic . . . . . . . . . . . . . . . . 8-5
Heating . . . . . . . . . . . . . . . . . . . 8-1, 8-4
Clock . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-7
Cluster, Instrument . . . . . . . . . . . . 5-11
Collision Damage Repair . . . . . 13-14
Compass . . . . . . . . . . . . . . . . . . . . . . . 5-5 Connections
OnStar®. . . . . . . . . . . . . . . . . . . . . . 14-3
Control of a Vehicle . . . . . . . . . . . . . 9-3
Convex Mirrors . . . . . . . . . . . . . . . . 2-13
Coolant Engine . . . . . . . . . . . . . . . . . . . . . . 10-17
Engine TemperatureGauge . . . . . . . . . . . . . . . . . . . . . . 5-15
Cooling System . . . . . . . . . . . . . . . 10-16 Engine Messages . . . . . . . . . . . . 5-39
Courtesy Transportation
Program . . . . . . . . . . . . . . . . . . . . . 13-13
Cruise Control . . . . . . . . . . . . . . . . . 9-56 Light . . . . . . . . . . . . . . . . . . . . . . . . . . 5-28
Cupholders . . . . . . . . . . . . . . . . . . . . . 4-1
Customer Assistance . . . . . . . . . . 13-6 Offices . . . . . . . . . . . . . . . . . . . . . . . . 13-5
Text Telephone (TTY)Users . . . . . . . . . . . . . . . . . . . . . . . 13-6
Customer Information Service Publications
Ordering Information . . . . . . 13-16
Customer Satisfaction Procedure . . . . . . . . . . . . . . 13-2, 13-4D
Damage Repair, Collision . . . . . 13-14
Danger, Warnings, andCautions . . . . . . . . . . . . . . . . . . . . . . . . iv
Data Recorders, Event . . . . . . . 13-19
Daytime Running Lamps (DRL) . . . . . . . . . . . . . . . . . . 6-3
Defensive Driving . . . . . . . . . . . . . . . 9-3
Delayed Locking . . . . . . . . . . . . . . . . 2-7
Devices Auxiliary . . . . . . . . . . . . . . . . . . . . . . 7-33
Diagnostics OnStar
®. . . . . . . . . . . . . . . . . . . . . . 14-5
Distracted Driving . . . . . . . . . . . . . . . 9-2
Dome Lamps . . . . . . . . . . . . . . . . . . . 6-7
Door Ajar Messages . . . . . . . . . . . . . . . 5-38
Delayed Locking . . . . . . . . . . . . . . . 2-7
Locks . . . . . . . . . . . . . . . . . . . . . . . . . . 2-6
Power Locks . . . . . . . . . . . . . . . . . . . 2-7
Rear Doors . . . . . . . . . . . . . . . . . . . . 2-8
Drive Belt Routing, Engine . . . . . 12-6
Driver Information Center (DIC) . . . . . . . . . . . . . . . . . 5-28

Black plate (4,1)GMC Sierra Owner Manual - 2013 - crc - 8/14/12
i-4 INDEX
DrivingCharacteristics and
Towing Tips . . . . . . . . . . . . . . . . . 9-71
Defensive . . . . . . . . . . . . . . . . . . . . . . 9-3
Drunk . . . . . . . . . . . . . . . . . . . . . . . . . . 9-3
For Better Fuel Economy . . . . . 1-33
Highway Hypnosis . . . . . . . . . . . . 9-11
Hill and Mountain Roads . . . . . . 9-11
If the Vehicle is Stuck . . . . . . . . . 9-14
Loss of Control . . . . . . . . . . . . . . . . 9-5
Off-Road . . . . . . . . . . . . . . . . . . . . . . 9-5
Off-Road Recovery . . . . . . . . . . . . 9-4
Vehicle Load Limits . . . . . . . . . . . 9-15
Wet Roads . . . . . . . . . . . . . . . . . . . 9-10
Winter . . . . . . . . . . . . . . . . . . . . . . . . 9-12
Dual Automatic Climate
Control System . . . . . . . . . . . . . . . . 8-5
Dual Tire Rotation . . . . . . . . . . . . . . . . . . . . 10-63
DVD Rear Seat Entertainment
System . . . . . . . . . . . . . . . . . . . . . . 7-38
DVD/CD Player . . . . . . . . . . . . . . . . 7-23E
E85 Fuel . . . . . . . . . . . . . . . . . . . . . . . 9-68
Electrical Equipment, Add-On . . . . . . . . . . . . . . . . . . . . . 9-101
Electrical System Engine CompartmentFuse Block . . . . . . . . . . . . . . . . 10-39
Fuses and Circuit Breakers . . . . . . . . . . . . . . . . . . 10-39
Instrument Panel Fuse Block . . . . . . . . . . . . . . . . . . . . . . 10-43
Overload . . . . . . . . . . . . . . . . . . . 10-38
Emergency OnStar
®. . . . . . . . . . . . . . . . . . . . . . 14-2
Engine Air Cleaner/Filter . . . . . . . . . . . 10-15
Check and Service Engine
Soon Light . . . . . . . . . . . . . . . . . . 5-21
Compartment Overview . . . . . . . 10-5
Coolant . . . . . . . . . . . . . . . . . . . . . 10-17
Coolant Heater . . . . . . . . . . . . . . . 9-28
Coolant Temperature Gauge . . . . . . . . . . . . . . . . . . . . . . 5-15 Engine (cont'd)
Cooling System . . . . . . . . . . . . . 10-16
Cooling System Messages . . . 5-39
Drive Belt Routing . . . . . . . . . . . . 12-6
Exhaust . . . . . . . . . . . . . . . . . . . . . . 9-31
Fan . . . . . . . . . . . . . . . . . . . . . . . . . 10-22
Oil Life System . . . . . . . . . . . . . . . 10-9
Oil Messages . . . . . . . . . . . . . . . . . 5-40
Oil Pressure Gauge . . . . . . . . . . 5-14
Overheated Protection
Operating Mode . . . . . . . . . . . 10-22
Overheating . . . . . . . . . . . . . . . . 10-20
Power Messages . . . . . . . . . . . . . 5-40
Pressure Light . . . . . . . . . . . . . . . . 5-26
Running While Parked . . . . . . . . 9-32
Starting . . . . . . . . . . . . . . . . . . . . . . . 9-25
Entry Lighting . . . . . . . . . . . . . . . . . . . 6-8
Equipment, Towing . . . . . . . . . . . . 9-89
Event Data Recorders . . . . . . . . 13-19
Exit Lighting . . . . . . . . . . . . . . . . . . . . 6-8
Extender, Safety Belt . . . . . . . . . . 3-19
Exterior Lamp Controls . . . . . . . . . 6-1
Exterior Lamps Off Reminder . . . 6-2

Black plate (5,1)GMC Sierra Owner Manual - 2013 - crc - 8/14/12
INDEX i-5
F
FanEngine . . . . . . . . . . . . . . . . . . . . . . 10-22
Fast Idle System . . . . . . . . . . . . . . . 9-27
Features Memory . . . . . . . . . . . . . . . . . . . . . . . 1-12
Filter,
Engine Air Cleaner . . . . . . . . . 10-15
Flash-to-Pass . . . . . . . . . . . . . . . . . . . 6-3
Flashers, Hazard Warning . . . . . . 6-5
Flat Tire . . . . . . . . . . . . . . . . . . . . . . 10-70 Changing . . . . . . . . . . . . . . . . . . . 10-72
Floor Mats . . . . . . . . . . . . . . . . . . . . 10-97
Fluid AutomaticTransmission . . . . . . . 10-10, 10-12
Brakes . . . . . . . . . . . . . . . . . . . . . . 10-25
Four-Wheel Drive Transfer Case . . . . . . . . . . . . . . . 9-38
Power Steering . . . . . . . . . . . . . 10-23
Washer . . . . . . . . . . . . . . . . . . . . . 10-23
Fog Lamps Bulb Replacement . . . . . . . . . . . . . 6-6
Folding Mirrors . . . . . . . . . . . . . . . . 2-15 Four-Wheel Drive . . . . . . . 10-28, 9-38
Four-Wheel-Drive Light . . . . . . . . 5-25
Front Axle . . . . . . . . . . . . . . . . . . . . 10-29
Front Fog Lamp
Light . . . . . . . . . . . . . . . . . . . . . . . . . . 5-28
Front Seats Adjustment . . . . . . . . . . . . . . . . . . . . 3-3
Heated and Ventilated . . . . . . . . . 3-8
Fuel . . . . . . . . . . . . . . . . . . . . . . . . . . . 9-65 Additives . . . . . . . . . . . . . . . . . . . . . 9-67
E85 (85% Ethanol) . . . . . . . . . . . 9-68
Economy Driving . . . . . . . . . . . . . 1-33
Filling a Portable FuelContainer . . . . . . . . . . . . . . . . . . . 9-70
Filling the Tank . . . . . . . . . . . . . . . 9-68
Foreign Countries . . . . . . . . . . . . 9-66
Gasoline Specifications . . . . . . . 9-66
Gauge . . . . . . . . . . . . . . . . . . . . . . . . 5-13
Low Fuel Warning Light . . . . . . . 5-27
Management, Active . . . . . . . . . . 9-30
Recommended . . . . . . . . . . . . . . . 9-66
Requirements, California . . . . . 9-66
System Messages . . . . . . . . . . . . 5-41
Full-Size Spare Tire . . . . . . . . . . 10-82 Fuses
Engine Compartment
Fuse Block . . . . . . . . . . . . . . . . 10-39
Fuses and Circuit Breakers . . . . . . . . . . . . . . . . . . 10-39
Instrument Panel Fuse Block . . . . . . . . . . . . . . . . . . . . . . 10-43
G
Garage Door Opener . . . . . . . . . . 5-54
Programming . . . . . . . . . . . . . . . . . 5-54
Gasoline Specifications . . . . . . . . . . . . . . . . . 9-66
Gauges Engine CoolantTemperature . . . . . . . . . . . . . . . . 5-15
Engine Oil Pressure . . . . . . . . . . 5-14
Fuel . . . . . . . . . . . . . . . . . . . . . . . . . . 5-13
Odometer . . . . . . . . . . . . . . . . . . . . . 5-12
Speedometer . . . . . . . . . . . . . . . . . 5-12
Tachometer . . . . . . . . . . . . . . . . . . . 5-12
Trip Odometer . . . . . . . . . . . . . . . . 5-12
Voltmeter . . . . . . . . . . . . . . . . . . . . . 5-15
Warning Lights and Indicators . . . . . . . . . . . . . . . . . . . 5-10