2012 CHEVROLET SUBURBAN automatic transmission

Black plate (34,1)Chevrolet Tahoe/Suburban Owner Manual - 2012
9-34 Driving and Operating
If you manually select 2 (Second)
in an automatic transmission,
the transmission will start in
second gear. You can use this
feature for reducing the speed of the
rear wheels when you are trying to
start the vehicle from a stop on
slippery road surfaces.
1 (First):This position reduces
vehicle speed without using the
brakes. You can use it for major/
severe downgrades and off-road
driving where the vehicle would
otherwise accelerate due to
steepness of grade. When you shift
to 1 (First) it provides the lowest
gear appropriate to the vehicle's
current road speed and continues
to downshift as the vehicle slows,
eventually downshifting to
1 (First) gear.
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 the vehicle
warranty. If you are stuck, do not spin the tires. When stopping on
a hill, use the brakes to hold the
vehicle in place.
Manual Mode
Range Selection Mode
(Hydra-Matic®6-Speed
Transmission)
Base Trim Shown (Uplevel Similar)
The vehicle may have a Range
Selection Mode. The Range
Selection Mode helps control the
vehicle's transmission and vehicle
speed while driving down hill or
towing a trailer by letting you select
a desired range of gears. To use this feature, do the following:
1. Move the shift lever to
M (Manual Mode).
2. Press the plus/minus buttons, located on the steering column
shift lever, to select the desired
range of gears for the current
driving conditions.
When M (Manual Mode) is selected
a number displays next to the M,
indicating the current gear.
This number is the highest gear
that can be used. However, the
vehicle can automatically shift to
lower gears as it adjusts to driving
conditions. This means that all
gears below that number are
available. When 5 (Fifth) is selected,
1 (First) through 5 (Fifth) gears are
automatically shifted by the vehicle,
but 6 (Sixth) cannot be used until
the plus/minus button located on the
steering column lever is used to
change to the gear.

Black plate (35,1)Chevrolet Tahoe/Suburban Owner Manual - 2012
Driving and Operating 9-35
Grade Braking is not available when
Range Selection Mode is active.
SeeTow/Haul Mode on page 9‑35.
While using Range Selection Mode,
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 the vehicle
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 the vehicle has the Hydra-Matic®
6-Speed Automatic Transmission,
it has a Low Traction Mode that
assists 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 Range Selection Mode. This will limit
torque to the wheels after it detects
wheel slip, preventing the tires from
spinning.
Tow/Haul Mode
The vehicle has a Tow/Haul Mode.
The selector button is located on the
end of the column shift lever. You
can use this feature to assist when
driving down steep hills or mountain
grades, towing, or hauling a heavy
load, or if there is a need to charge
a battery installed in a trailer. See
Towing Equipment on page 9‑75
and
Hill and Mountain Roads on
page 9‑12 for more information.
When Tow/Haul Mode is selected
the tow/haul indicator light will come
on. SeeTow/Haul Mode Light on
page 5‑22.
The Tow/Haul Mode works with the
Autoride
®feature, if the vehicle
has this, to enhance the ride when
trailering or with a loaded vehicle.
See Continuous Damping Control
(CDC) on page 9‑48.
Grade Braking (Hydra-Matic®
6-Speed Automatic
Transmission)
The Grade Braking shift modes
can be activated by pressing the
button on the end of the shift control
lever. While in Range Selection
Mode, Grade Braking is deactivated
allowing the driver to select a
desired range of gears.

Black plate (36,1)Chevrolet Tahoe/Suburban Owner Manual - 2012
9-36 Driving and Operating
Grade Braking is only active while
the Tow/Haul Mode is selected and
you are not in the Range Selection
Mode. See“Tow/Haul Mode” listed
previously and Manual Mode on
page 9‑34 for more information on
the Range Selection Mode. Grade
Braking assists in maintaining
desired vehicle speeds when driving
on downhill grades by automatically
implementing a shift schedule that
utilizes the engine and transmission
to slow the vehicle. This reduces
wear on the braking system and
increases control of the vehicle.
Grade Braking monitors vehicle
speed, acceleration, engine torque
and brake pedal usage. Using this
information, it detects when the
truck is on a downhill grade and the
driver desires to slow the vehicle by
pressing the brake.
Also see Towing Equipment on
page 9‑75 for more information.Drive Systems
Four-Wheel Drive
(Two Speed Automatic
Transfer Case)
If the vehicle has four-wheel drive,
you can send the engine's driving
power to all four wheels for extra
traction. Read the following before
using four-wheel drive.
Notice:Driving on clean, dry
pavement in Four-Wheel Drive
High or Four-Wheel Drive Low
for an extended period of time
may cause premature wear on
the vehicle's powertrain. Do not
drive on clean, dry pavement
in Four-Wheel Drive High or
Four-Wheel Drive Low for
extended periods of time. While driving on clean dry pavement
and during tight turns, you may
experience a vibration in the
steering system.
The vehicle has StabiliTrak
®.
Shifting into Four-Wheel Drive Low
will turn Traction Control and
StabiliTrak off. See StabiliTrak
®
System on page 9‑45.
Front Axle
The front axle engages and
disengages automatically when you
shift the transfer case. Some delay
for the axle to engage or disengage
is normal.

Black plate (38,1)Chevrolet Tahoe/Suburban Owner Manual - 2012
9-38 Driving and Operating
The vehicle has StabiliTrak. Shifting
into Four-Wheel Drive Low will turn
Traction Control and StabiliTrak
off. SeeStabiliTrak
®System on
page 9‑45.
{WARNING
Shifting the transfer case to
N (Neutral) can cause the vehicle
to roll even if the transmission is
in P (Park). You or someone else
could be seriously injured. Be
sure to set the parking brake
before placing the transfer case in
N (Neutral). See Parking Brake on
page 9‑44.
N (Neutral): Shift the vehicle's
transfer case to N (Neutral) only
when towing the vehicle. See
Recreational Vehicle Towing on
page 10‑87 orTowing the Vehicle
on page 10‑87 for more information.
If the SERVICE 4 WHEEL DRIVE
message stays on, you should
take the vehicle to your dealer for service. See
“SERVICE 4 WHEEL
DRIVE” message under
Transmission Messages on
page 5‑43.
Shifting Into Four-Wheel Drive
High or AUTO (Automatic
Four-Wheel Drive)
Turn the knob to the Four-Wheel
Drive High or AUTO position. This
can be done at any speed, except
when shifting from Four-Wheel
Drive Low. The indicator light will
flash while shifting. It will remain on
when the shift is completed.
Shifting Into Two-Wheel
Drive High
Turn the knob to the Two-Wheel
Drive High position. This can be
done at any speed, except when
shifting from Four-Wheel Drive Low.
See “Shifting Out of Four-Wheel
Drive Low” in this section for more
information. Shifting Into Four-Wheel
Drive Low
When Four-Wheel Drive Low is
engaged, vehicle speed should
be kept below 72 km/h (45 mph).
Extended high-speed operation
in 4L may damage or shorten the life
of the drivetrain.
To shift to the Four-Wheel Drive
Low position, the ignition must be in
ON/RUN and the vehicle must be
stopped or moving less than 5 km/h
(3 mph) with the transmission in
N (Neutral). The preferred method
for shifting into Four-Wheel Drive
Low is to have the vehicle moving
1.6 to 3.2 km/h (1 to 2 mph). Turn
the knob to the Four-Wheel Drive
Low position. You must wait for the
Four-Wheel Drive Low indicator light
to stop flashing and remain on
before shifting the transmission
into gear.

Black plate (42,1)Chevrolet Tahoe/Suburban Owner Manual - 2012
9-42 Driving and Operating
You can choose among three
driving settings:
Indicator lights in the switch show
you which setting you are in. The
indicator lights will come on briefly
when you turn on the ignition and
the last chosen setting will stay on.
If the lights do not come on, you
should take the vehicle to your
dealer for service. An indicator light
will flash while shifting. It will stay on
when the shift is completed. 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 the vehicle in AUTO, the
front axle is engaged, and the
vehicle's 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 you need extra traction, such
as on snowy or icy roads or in most
off-road situations. This setting also
engages the front axle to help drive
the vehicle. This is the best setting
to use when plowing snow.
Service Four‐Wheel Drive
If the SERVICE 4 WHEEL DRIVE
message stays on, you should
take the vehicle to your dealer for
service. See “SERVICE 4 WHEEL
DRIVE” message under
Transmission Messages on
page 5‑43. Shifting Into Four-Wheel Drive
High or AUTO (Automatic
Four-Wheel Drive)
Turn the knob to the Four-Wheel
Drive High or AUTO position. This
can be done at any speed. The
indicator light will flash while
shifting. It will remain on when the
shift is completed.
Shifting Into Two-Wheel
Drive High
Turn the knob to the Two-Wheel
Drive High position. This can be
done at any speed. The indicator
light will flash while shifting. It
will remain on when the shift is
completed.
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.

Black plate (47,1)Chevrolet Tahoe/Suburban Owner Manual - 2012
Driving and Operating 9-47
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 9‑15.
When the transfer case is in 4LO,
the stability system is automatically
disabled, the StabiliTrak light comes
on, and the appropriate message
will appear on the DIC. Both
traction control and StabiliTrak are
automatically disabled in this
condition.Traction Control Operation
The TCS 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 TCS 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.
The TCS may activate on dry or
rough roads or under conditions
such as heavy acceleration while
turning or abrupt upshifts/downshifts
of the transmission. When this
happens, a reduction in acceleration
may be noticed, or a noise or
vibration may be heard. This is
normal.
If cruise control is being used when
the system activates, the StabiliTrak
light will flash and cruise control will
automatically disengage. Cruise
control may be reengaged when
road conditions allow. See Cruise
Control on page 9‑49.

Black plate (51,1)Chevrolet Tahoe/Suburban Owner Manual - 2012
Driving and Operating 9-51
Using Cruise Control on Hills
How well the cruise control works
on hills depends on the vehicle
speed, the load, and the steepness
of the hills. When going up steep
hills, pressing the accelerator pedal
may be necessary to maintain
vehicle speed.
While going downhill, the Cruise
Grade Braking feature may
automatically shift to a lower gear
to keep the vehicle's speed down.
It may be necessary to apply
the brake or manually shift the
transmission to a lower gear. The
vehicle may shift to a higher gear
when grade braking assistance is
no longer required. Cruise Grade
Braking is not available while in
Range Selection Mode. See "Range
Selection Mode" underManual
Mode on page 9‑34. When the brakes are manually
applied the cruise control is
disengaged.
Ending Cruise Control
There are three ways to end cruise
control:
.To disengage cruise control,
step lightly on the brake pedal.
.Press the[on the steering
wheel.
.To turn off the cruise control,
press
Ion the steering wheel.
Erasing Speed Memory
The cruise control set speed is
erased from memory by pressing
the
Ibutton or if the ignition is
turned off.
Object Detection
Systems
Ultrasonic Parking Assist
If available, the Ultrasonic Rear
Parking Assist (URPA) system uses
sensors on the rear bumper to
assist with parking and avoiding
objects while in R (Reverse).
{WARNING
The URPA system does not
detect pedestrians, bicyclists,
animals, or any other objects
located below the bumper or that
are too close or too far from the
vehicle. To prevent injury, death,
or vehicle damage, even with
URPA, always check behind the
vehicle and check all mirrors
before backing.

Black plate (68,1)Chevrolet Tahoe/Suburban Owner Manual - 2012
9-68 Driving and Operating
Backing Up
Hold the bottom of the steering
wheel with one hand. Then, 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 Light on
page 5‑22.
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)
for a few minutes before turning the
engine off. If the overheat warning
comes on, see
Engine Overheating
on page 10‑19.
Parking on Hills
{WARNING
Parking the vehicle on a hill
with the trailer attached can be
dangerous. If something goes
wrong, the rig could start to move.
People can be injured, and both
the vehicle and the trailer can be
damaged. When possible, always
park the rig on a flat surface.