2007 GMC SIERRA ECO mode

If your vehicle does not have a rear seat that will
accommodate a rear-facing child restraint, we
recommend that rear-facing child restraints not
be transported in your vehicle, even if the airbag
is off.
{CAUTION:
A child in a child restraint in the center
front seat can be badly injured or killed by
the right front passenger’s airbag if it
inates. Never secure a child restraint in
the center front seat. It is always better to
secure a child restraint in the rear seat.
Do not use child restraints in the center front seat
position. The restraints will not work properly.
There is limited space in the rear seating area of
an extended cab model. If you want to secure
a child restraint in a rear seating position of
an extended cab model, especially in the rear
center position, be sure to study the instructions
that came with your child restraint to see if there is
enough room to secure your seat properly.If your vehicle has the passenger sensing system
or the airbag off switch and you need to secure
a rear-facing child restraint in the right front
passenger’s seat, the passenger’s frontal airbag
must be off. SeePassenger Sensing System
on page 97,Airbag Off Switch on page 93, and
Securing a Child Restraint in the Right Front Seat
Position (With Airbag Off Switch) on page 70or
Securing a Child Restraint in the Right Front Seat
Position (With Passenger Sensing System) on
page 76for more on this, including important
safety information.
Wherever you install a child restraint, be sure to
secure the child restraint properly.
Keep in mind that an unsecured child restraint can
move around in a collision or sudden stop and
injure people in the vehicle. Be sure to properly
secure any child restraint in your vehicle — even
when no child is in it.
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Regular Cab Models
1. If the child restraint manufacturer recommends
that the top tether be attached, attach and
tighten the top tether to the top tether anchor,
if your vehicle has one. Refer to the child
restraint instructions and the following steps:
1.1. Pull the passenger seatback forward
by pulling the recliner handle upward to
access the top tether anchor. See
Reclining Seatbacks on page 15for
additional information.
1.2. Find the top tether anchor.
1.3. Remove the trim cover to expose the
anchor.1.4. Route, attach, and tighten the top tether
according to your child restraint
instructions and the following
instructions:
If the position you are
using has an adjustable
head restraint and
you are using a dual
tether, route the
tether around the head
restraint.
If the position you are
using has an adjustable
head restraint and
you are using a single
tether, raise the
head restraint and route
the tether under the
head restraint and
in between the head
restraint posts.
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Active Fuel Management™
Your vehicle’s V8 engine may have Active Fuel
Management™. This system allows the engine to
operate on either all or half of its cylinders,
depending on the driving conditions.
When less power is required, such as cruising at a
constant vehicle speed, the system will operate
in the half cylinder mode, allowing your vehicle to
achieve better fuel economy. When greater
power demands are required, such as accelerating
from a stop, passing, or merging onto a freeway,
the system will maintain full-cylinder operation.
Your vehicle has an Active Fuel Management™
indicator. For more information on using this
display seeDIC Operation and Displays (With DIC
Buttons) on page 268orDIC Operation and
Displays (Without DIC Buttons) on page 275.
Automatic Transmission Operation
If your vehicle is has an automatic transmission,
it has an electronic shift position indicator
within the instrument panel cluster. This display
comes on when the ignition key is turned to
the RUN position.There are several different positions for the
shift lever.
See “Range Selection Mode” later in this section.
PARK (P):This position locks your rear wheels. It
is the best position to use when you start the engine
because your vehicle cannot move easily.
Hydra-Matic®4-Speed Automatic Transmission
Allison Transmission®or Hydra-Matic®6-Speed
Automatic Transmission
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Grade Braking is not available when the Range
Selection Mode is active. SeeTow/Haul Mode on
page 144.
While using the Range Selection mode feature,
cruise control and the Tow/Haul mode can
be used.
Notice:Spinning the tires or holding the
vehicle in one place on a hill using only the
accelerator pedal may damage the
transmission. The repair will not be covered by
your warranty. If you are stuck, do not spin
the tires. When stopping on a hill, use the
brakes to hold the vehicle in place.
Low Traction Mode
If your vehicle has the Allison Transmission®,or
the Hydra-Matic®6-Speed Automatic
Transmission, it has a Low Traction Mode that
assist in vehicle acceleration when road conditions
are slippery, such as with ice or snow. While
the vehicle is at a stop, select the second gear
range using the Range Selection system. This will
limit torque to the wheels after it detects wheel
slip, preventing the tires from spinning.
Tow/Haul Mode
If your vehicle has an automatic transmission, it
has a tow/haul mode. If your vehicle has an Allison
or Hydra-Matic
®6-speed automatic transmission
see “Tow/Haul Mode (Allison or Hydra-Matic®
6-Speed Automatic Transmission®) following.
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When Using the Manual Transfer Case

Shifting should be made using quick
motions. Shifting slowly may make it more
difficult to shift.
You may notice that it is harder to shift when
the vehicle is cold. After the vehicle warms
up the shifting will return to normal.
While in Four-Wheel High or Four-Wheel-Drive
Low you may experience reduced fuel
economy.
Avoid driving in Four-Wheel Drive on clean, dry
pavement. It may cause your tires to wear
faster, and make the transfer case harder to
shift and run noisier.
If the transfer case shifter is in the NEUTRAL
position and you have difficulty reaching the
selected transfer case mode, with the engine
running, shift the transmission momentarily to
drive and then back to NEUTRAL. This will
realign the gear teeth in the transfer case and
allow you to complete the shift.
Shifting from Two-Wheel-Drive High to
Four-Wheel-Drive High

Shifts between Two-Wheel-Drive High and
Four-Wheel-Drive High can be made at
any vehicle speed.
Shift the transfer case lever in one continuous
motion into either the Four-Wheel-Drive High
or Two-Wheel-Drive High position.
In extremely cold weather, it may be
necessary to slow or stop the vehicle to shift
into Four-wheel-Drive High until your
vehicle has warmed up.
While in Four-Wheel-Drive High, your vehicle
can be driven at any posted legal speed limit.
150

You must wait for the Four-Wheel-Drive Low
indicator light to stop ashing and remain on before
shifting your transmission in gear.
Notice:Shifting the transmission into gear
before the requested mode indicator light has
stopped ashing could damage the transfer
case. To help avoid damaging your vehicle,
always wait for the mode indicator lights
to stop ashing before shifting the
transmission into gear.
It is typical for your vehicle to exhibit signicant
engagement noise and bump when shifting
between Four-Wheel-Drive Low and
Four-Wheel-Drive High ranges or from NEUTRAL
with the engine running.
If the knob is turned to the Four-Wheel-Drive Low
position when your vehicle is in gear and/or
moving, the Four-Wheel-Drive Low indicator light
will ash for 30 seconds and not complete the
shift unless your vehicle is moving less than 3 mph
(5 km/h) and the transmission is in NEUTRAL (N).
After 30 seconds the transfer case will shift to
Four-Wheel-Drive High mode.Shifting Out of Four-Wheel-Drive Low
To shift from Four-Wheel-Drive Low to
Four-Wheel-Drive High, or Two-Wheel-Drive High,
your vehicle must be stopped or moving less
than 3 mph (5 km/h) with the transmission
in NEUTRAL (N) and the ignition in RUN. The
preferred method for shifting out of
Four-Wheel-Drive Low is to have your vehicle
moving 1 to 2 mph (1.6 to 3.2 km/h). Turn the knob
to the Four-Wheel-Drive High, or Two-Wheel-Drive
High position. You must wait for the
Four-Wheel-Drive High, or Two-Wheel-Drive High
indicator light to stop ashing and remain on
before shifting the transmission into gear.
Notice:Shifting the transmission into gear
before the requested mode indicator light has
stopped ashing could damage the transfer
case. To help avoid damaging your vehicle,
always wait for the mode indicator lights
to stop ashing before shifting the
transmission into gear.
It is typical for your vehicle to exhibit signicant
engagement noise and bump when shifting
between Four-Wheel-Drive Low and
Four-Wheel-Drive High ranges or from NEUTRAL
with the engine running.
154

Shifting Out of NEUTRAL
To shift out of NEUTRAL do the following:
1. Set the parking brake and apply the regular
brake pedal.
2. Shift the transmission to NEUTRAL (N) and
turn the ignition to RUN with the engine off.
3. Turn the transfer case dial to
Two-Wheel-Drive High.
After the transfer case has shifted out of
NEUTRAL the 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 ashing could damage the transfer
case. To help avoid damaging your vehicle,
always wait for the mode indicator lights
to stop ashing before shifting the
transmission into gear.
5. Start the engine and shift the transmission to
the desired position.Excessively shifting the transfer case into or out of
the different modes may cause the transfer
case to enter the shift protection mode. This will
protect the transfer case from possible damage
and will only allow the transfer case to respond to
one shift per 10 seconds. The transfer case
may stay in this mode for up to three minutes.
Automatic Transfer Case
The transfer case knob
is located next to the
steering column.
For information on StabiliTrak
®, seeStabiliTrak®
System on page 381.
156

Use the dial to shift into and out of
Four-Wheel Drive.
You can choose among ve driving settings:
Indicator lights in the dial show which setting you
are in. The indicator lights will come on briey
when you turn on the ignition and one will stay on.
If the lights do not come on, you should take
your vehicle to your dealer for service. An indicator
light will ash while shifting the transfer case. It
will remain illuminated when the shift is complete.
If for some reason the transfer case cannot
make a requested shift, it will return to the last
chosen setting.
2
m(Two-Wheel-Drive High):This setting is
used for driving in most street and highway
situations. The front axle is not engaged in
Two-Wheel Drive. This setting also provides the
best fuel economy.AUTO (Automatic Four-Wheel Drive):This
setting is ideal for use when road surface traction
conditions are variable. When driving your
vehicle in AUTO, the front axle is engaged, but
the vehicle’s power is sent only to the front
and rear wheels automatically based on driving
conditions. Power is sent to the front and rear
wheels automatically based on driving conditions.
Driving in this mode results in slightly lower
fuel economy than Two-Wheel-Drive High.
4
m(Four-Wheel-Drive High):Use the
Four-Wheel-Drive High position when extra traction
is needed, such as on snowy or icy roads or in
most off-road situations. This setting also engages
the front axle to help drive your vehicle. This is
the best setting to use when plowing snow.
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