2011 GMC SIERRA ECO mode

Black plate (67,1)GMC Sierra Owner Manual - 2011
Driving and Operating 9-67
6. Turn the transfer case dialclockwise to N (Neutral) until
it stops and hold it there until
the N (Neutral) light starts
blinking. This will take at least
10 seconds. Then slowly release
the dial to the four low position.
The N (Neutral) light will come
on when the transfer case shift
to N (Neutral) is complete.
7. If the engine is running, make sure that the transfer case is
in N (Neutral) by shifting the
transmission to R (Reverse)
for one second, then shift the
transmission to D (Drive) for
one second.
8. Turn the ignition to ACC/ACCESSORY, which
will turn the engine off.
9. Place the transmission shift lever in P (Park). 10. Release the parking brake prior
to moving the vehicle.
11. Turn the ignition to LOCK/OFF.
Shifting Out of Neutral
To shift out of N (Neutral) do the
following:
1. Set the parking brake and apply the regular brake pedal.
2. Turn the ignition to ON/RUN with the engine off, and shift the
transmission to N (Neutral).
3. Turn the transfer case dial to Two-Wheel Drive High,
Four-Wheel Drive High,
or AUTO.
After the transfer case has
shifted out of N (Neutral), the
N (Neutral) light will go out. 4. Release the parking brake prior
to moving the vehicle.
Notice: Shifting the transmission
into gear before the requested
mode indicator light has stopped
flashing could damage the
transfer case. To help avoid
damaging the vehicle, always
wait for the mode indicator lights
to stop flashing before shifting
the transmission into gear.
5. Start the engine and shift the transmission to the desired
position.

Black plate (72,1)GMC Sierra Owner Manual - 2011
9-72 Driving and Operating
When TCS or StabiliTrak is
turned off, the StabiliTrak light
and the appropriate message
will be displayed on the DIC to
warn the driver. The vehicle will
still have brake-traction control
when traction control is off, but will
not be able to use the engine speed
management system. See“Traction
Control Operation” next for more
information.
When the traction control system
has been turned off, system noises
may still be heard as a result of the
brake-traction control coming on.
It is recommended to leave the
system on for normal driving
conditions, but it may be necessary
to turn the system off if the vehicle
is stuck in sand, mud, ice or snow,
and you want to “rock”the vehicle
to attempt to free it. It may also be
necessary to turn off the system
when driving in extreme off-road
conditions where high wheel spin
is required. See If the Vehicle is
Stuck on page 9‑23. When the transfer case is in 4LO,
the stability system is automatically
disabled, the StabiliTrak light comes
on, and the STABILITRAK OFF
message will appear on the DIC.
Both traction control and StabiliTrak
are automatically disabled in this
condition.
Traction Control Operation
The traction control system is part
of the StabiliTrak system. Traction
control limits wheel spin by reducing
engine power to the wheels (engine
speed management) and by
applying brakes to each individual
wheel (brake-traction control) as
necessary.
The traction control system is
enabled automatically when the
vehicle is started. It will activate
and the StabiliTrak light will flash
if it senses that any of the wheels
are spinning or beginning to lose
traction while driving. If traction
control is turned off, only the
brake-traction control portion
of traction control will work.
The engine speed management
will be disabled. In this mode,
engine power is not reduced
automatically and the driven
wheels can spin more freely.
This can cause the brake-traction
control to activate constantly.
Notice:
If the wheel(s) of one axle
is allowed to spin excessively
while the StabiliTrak
®, ABS, brake
warning lights, and any relevant
DIC messages are displayed, the
transfer case could be damaged.
The repairs would not be covered
by the vehicle warranty. Reduce
engine power and do not spin
the wheel(s) excessively while
these lights and messages are
displayed.

Black plate (89,1)GMC Sierra Owner Manual - 2011
Driving and Operating 9-89
{WARNING
Fuel can spray out on you if you
open the fuel cap too quickly.
If you spill fuel and then
something ignites it, you could be
badly burned. This spray can
happen if the tank is nearly full,
and is more likely in hot weather.
Open the fuel cap slowly and wait
for any hiss noise to stop. Then
unscrew the cap all the way.
If the vehicle is a dual fuel tank
chassis cab model, and it runs out
of fuel, refuel the front fuel tank first
to ensure a quick restart.
Be careful not to spill fuel. Do not
top off or overfill the tank and wait a
few seconds after you have finished pumping before removing the
nozzle. Clean fuel from painted
surfaces as soon as possible.
See
Exterior Care on page 10‑108.
When replacing the fuel cap, turn it
clockwise until it clicks. It will require
more effort to turn the fuel cap on
the last turn as you tighten it. Make
sure the cap is fully installed. The
diagnostic system can determine if
the fuel cap has been left off or
improperly installed. This would
allow fuel to evaporate into the
atmosphere. See Malfunction
Indicator Lamp on page 5‑25.
The TIGHTEN GAS CAP message
displays on the Driver Information
Center (DIC) if the fuel cap is not
properly installed. See Fuel System
Messages on page 5‑46 for more
information.
{WARNING
If a fire starts while you are
refueling, do not remove the
nozzle. Shut off the flow of fuel
by shutting off the pump or by
notifying the station attendant.
Leave the area immediately.
Notice: If a new fuel cap is
needed, be sure to get the right
type of cap from your dealer.
The wrong type of fuel cap might
not fit properly, might cause the
malfunction indicator lamp to
light, and could damage the
fuel tank and emissions system.
See Malfunction Indicator Lamp
on page 5‑25.

Black plate (96,1)GMC Sierra Owner Manual - 2011
9-96 Driving and Operating
Trailering is different than just
driving the vehicle by itself.
Trailering means changes in
handling, acceleration, braking,
durability, and fuel economy.
Successful, safe trailering takes
correct equipment, and it has to
be used properly.
The following information has many
time-tested, important trailering tips
and safety rules. Many of these are
important for your safety and that of
your passengers. So please read
this section carefully before pulling
a trailer.Weight of the Trailer
How heavy can a trailer safely be?
It depends on how the rig is used.
Speed, altitude, road grades,
outside temperature, and how much
the vehicle is used to pull a trailer
are all important. It can depend
on any special equipment on the
vehicle, and the amount of tongue
weight the vehicle can carry. See
“Weight of the Trailer Tongue”later
in this section for more information. Trailer weight rating (TWR) is
calculated assuming the tow vehicle
has only the driver but all required
trailering equipment. Weight of
additional optional equipment,
passengers, and cargo in the tow
vehicle must be subtracted from
the trailer weight rating.
Use the following chart to determine
how much the vehicle can weigh,
based upon the vehicle model and
options.
Weights listed apply for
conventional trailers and fifth-wheel
trailers unless otherwise noted.

Black plate (113,1)GMC Sierra Owner Manual - 2011
Driving and Operating 9-113
Fifth-Wheel and Gooseneck
Trailering
Fifth-wheel and gooseneck trailers
can be used with many pickup
models. These trailers place a
larger percentage of the weight
(kingpin weight) on the tow vehicle
than conventional trailers. Make
sure this weight does not cause the
vehicle to exceed GAWR or GVWR.
Fifth-wheel or gooseneck kingpin
weight should be 15 to 25 percent of
the trailer weight up to the maximum
amount specified in the trailering
chart for the vehicle. See“Weight of
the Trailer” underTrailer Towing on
page 9‑95 for more information. The hitch should be located in the
pickup bed so that its centerline is
over or slightly in front of the rear
axle. Take care that it is not so far
forward that it will contact the back
of the cab in sharp turns. This is
especially important for short box
pickups. Trailer pin box extensions
and sliding fifth-wheel hitch
assemblies can help this condition.
There should be at least six inches
of clearance between the top of the
pickup box and the bottom of the
trailer shelf that extends over
the box.
Make sure the hitch is attached to
the tow vehicle frame rails. Do not
use the pickup box for support.
Safety Chains
Always attach chains between the
vehicle and the trailer. Cross the
safety chains under the tongue
of the trailer to help prevent the
tongue from contacting the road
if it becomes separated from the
hitch. Instructions about safety
chains may be provided by the
hitch manufacturer or by the trailer
manufacturer. If the trailer being
towed weighs up to 2 271 kg
(5,000 lbs) with a factory-installed
step bumper, safety chains may
be attached to the attaching points
on the bumper; otherwise, safety
chains should be attached to holes
on the trailer hitch platform. Always
leave just enough slack so the
combination can turn. Never allow
safety chains to drag on the ground.

Black plate (115,1)GMC Sierra Owner Manual - 2011
Driving and Operating 9-115
Heavy-DutyTrailer Wiring Harness
Package
For vehicles equipped with heavy
duty trailering, the harness is
connected to a bracket on the hitch
platform. The seven-wire harness
contains the following trailer circuits:
.Yellow: Left Stop/Turn Signal
.Dark Green: Right Stop/Turn
Signal
.Brown: Taillamps
.White: Ground
.Light Green: Back-up Lamps
.Red: Battery Feed*
.Dark Blue: Trailer Brake*
*The fuses for these two circuits
are installed in the underhood
electrical center, but the wires are
not connected. They should be
connected by your dealer or a
qualified service center. The fuse
and wire for the ITBC is factory
installed and connected if the
vehicle is equipped with an ITBC.
The fuse for the battery feed is
not required if the vehicle has an
auxiliary battery. If the vehicle does
not have an auxiliary battery, have
your dealer or authorized service
center install the required fuse. If charging a remote (non-vehicle)
battery, press the Tow/Haul Mode
button, if equipped, located at
the end of the shift lever. This will
boost the vehicle system voltage
and properly charge the battery.
If the trailer is too light for Tow/
Haul Mode, or the vehicle is not
equipped with Tow/Haul, turn on
the headlamps as a second way
to boost the vehicle system and
charge the battery.

Black plate (117,1)GMC Sierra Owner Manual - 2011
Driving and Operating 9-117
If the vehicle is equipped with an
Integrated Trailer Brake Control
(ITBC) System, the blunt cuts
exist, but are not connected further
in the harness. If an aftermarket
trailer brake controller is installed,
the ITBC must be disconnected.
Do not power both ITBC and
aftermarket controllers to control
the trailer brakes at the same time.
Tow/Haul Mode
Pressing this button at the end of
the shift lever turns on and off the
Tow/Haul Mode.
This indicator light on the instrument
panel cluster comes on when the
Tow/Haul Mode is on.
Tow/Haul is a feature that assists
when pulling a heavy trailer or a
large or heavy load. SeeTow/Haul
Mode on page 9‑51 for more
information.
Tow/Haul is designed to be most
effective when the vehicle and
trailer combined weight is at least
75 percent of the vehicle's Gross
Combined Weight Rating (GCWR).
See “Weight of the Trailer” under
Trailer Towing on page 9‑95.
Tow/Haul is most useful under
the following driving conditions:
.When pulling a heavy trailer or
a large or heavy load through
rolling terrain.
.When pulling a heavy trailer
or a large or heavy load in
stop-and-go traffic.
.When pulling a heavy trailer
or a large or heavy load in busy
parking lots where improved low
speed control of the vehicle is
desired.
Operating the vehicle in Tow/Haul
when lightly loaded or with no
trailer at all will not cause damage.
However, there is no benefit to
the selection of Tow/Haul when
the vehicle is unloaded. Such a
selection when unloaded may
result in unpleasant engine and
transmission driving characteristics
and reduced fuel economy. Tow/
Haul is recommended only when
pulling a heavy trailer or a large
or heavy load.

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.