towing GMC SIERRA 1500 2009 User Guide

Grade Braking (Allison Transmission®
or 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.
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
Automatic Transmission Operation on page 2-28for
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 seeTowing a Trailer on page 4-53for more
information.
Cruise Grade Braking (Allison
Transmission®or Hydra-Matic®
6-Speed Automatic Transmission)
Cruise Grade Braking assists when driving on a downhill
grade. It maintains vehicle speed by automatically
implementing a shift schedule that uses the engine and
the transmission to slow the vehicle. Cruise Grade
Braking operates while Cruise Control is engaged in
Tow/Haul mode to assist in maintaining vehicle speed
under loaded vehicle conditions. It utilizes vehicle
acceleration and deviation from desired speed to
determine the correct gear for the operating condition.
If vehicle speed is above the desired speed the
transmission will downshift to slow the vehicle. If vehicle
speed is near or below desired speed the trans will
upshift, allowing vehicle speed to increase.
While in the Range Select Mode (RSM) mode, cruise
grade braking is not available.
SeeAutomatic Transmission Operation on page 2-28.
2-36

A Four-Wheel Drive
indicator light comes on
when you shift into
four-wheel drive and the
front axle engages.
SeeFour-Wheel-Drive
Light on page 3-51.
Some delay between shifting and when the indicator
light comes on is normal.
Recommended Transfer Case Settings
Driving ConditionsTransfer Case Settings
2m4m4nN
Normal YES
Severe YES
Extreme YES
Vehicle in Tow* YES
*SeeRecreational Vehicle Towing on page 4-47
Towing Your Vehicle on page 4-47Notice:Driving on clean, dry pavement in
four-wheel drive for an extended period of time can
cause premature wear on the vehicle’s powertrain.
Do not drive on clean, dry pavement in Four-Wheel
Drive for extended periods of time.
4
n(Four-Wheel-Drive Low):This setting also
engages the front axle and delivers extra torque.
You may never need Four-Wheel-Drive Low. It sends
maximum power to all four wheels. You might choose
Four-Wheel-Drive Low if you are driving off-road in deep
sand, deep mud, deep snow, and while climbing or
descending steep hills.
If the vehicle has StabiliTrak
®, shifting into
Four-Wheel-Drive Low will turn Traction Control and
StabiliTrak
®off. SeeStabiliTrak®System on page 4-6.
2-38

A parking brake symbol
is located next to the
N (Neutral) symbol as
a reminder to set the
parking brake before
shifting the transfer case
into N (Neutral).
{CAUTION:
Shifting the transfer case to 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 Neutral. SeeParking Brake on
page 2-50.N (Neutral):Shift to this setting only when the vehicle
needs to be towed. SeeRecreational Vehicle Towing
on page 4-47orTowing Your Vehicle on page 4-47.
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.
4
m(Four-Wheel-Drive High):Use this setting 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 your vehicle. This is the best
setting to use when plowing snow.
You can shift from Two-Wheel-Drive High to
Four-Wheel-Drive High or Four-Wheel-Drive High to
Two-Wheel-Drive High while the vehicle is moving.
In extremely cold weather, it may be necessary to stop
or slow the vehicle to shift into Four-Wheel-Drive High.
2-39

Electronic Transfer Case
The transfer case knob
is located next to the
steering column.
Use the dial to shift into and out of four-wheel drive.
Recommended Transfer Case Settings
Driving ConditionsTransfer Case Settings
2m4m4nN
Normal YES
Severe YES
Extreme YES
Vehicle in Tow* YES
*SeeRecreational Vehicle Towing on page 4-47
Towing Your Vehicle on page 4-47You can choose among four 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 the vehicle to your
dealer/retailer for service. An indicator light ashes while
shifting the transfer case and remains 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.
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 the vehicle. This is the best
setting to use when plowing snow.
4
n(Four-Wheel-Drive Low):This setting also engages
the front axle and delivers extra torque. You may
never need this setting. It sends maximum power to
all four wheels. You might choose Four-Wheel-Drive
Low while driving off-road in deep sand, deep mud, deep
snow, and while climbing or descending steep hills.
2-42

If the vehicle has StabiliTrak®, shifting into
Four-Wheel-Drive Low will turn Traction Control and
StabiliTrak
®off. SeeStabiliTrak®System on page 4-6.
{CAUTION:
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).
SeeParking Brake on page 2-50.
N (Neutral):Shift the vehicle’s transfer case to
N (Neutral) only when towing the vehicle. See
Recreational Vehicle Towing on page 4-47orTowing
Your Vehicle on page 4-47for more information.
If the SERVICE 4–Wheel Drive message stays on,
you should take the vehicle to your dealer/retailer for
service. See “Service 4–Wheel Drive message”
underDIC Warnings and Messages on page 3-66.
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 for more information.
Shifting Into Four-Wheel Drive Low
When Four-Wheel-Drive Low is engaged, vehicle speed
should be kept below 45 mph. Extended high-speed
operation in Four-Wheel-Drive Low 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 3 mph (5 km/h) with
the transmission in N (Neutral). The preferred method
for shifting into Four-Wheel-Drive Low is to have
the vehicle moving 1 to 2 mph (1.6 to 3.2 km/h).
Turn the knob to the Four-Wheel-Drive Low position.
You must wait for the Four-Wheel-Drive Low indicator
light to stop ashing and remain on before shifting
the 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 the vehicle, always wait for the mode
indicator lights to stop ashing before shifting the
transmission into gear.
2-43

{CAUTION:
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).
SeeParking Brake on page 2-50.
N (Neutral):Shift the vehicle’s transfer case to
N (Neutral) only when towing the vehicle. See
Recreational Vehicle Towing on page 4-47orTowing
Your Vehicle on page 4-47for more information.
If the SERVICE 4–Wheel Drive message stays on, you
should take the vehicle to your dealer/retailer for
service. See “Service 4–Wheel Drive message” under
DIC Warnings and Messages on page 3-66.
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 ash 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. The indicator light will ash while
shifting. It will remain on when the shift is completed.
Shifting Into Four-Wheel-Drive Low
When Four-Wheel-Drive Low is engaged, vehicle speed
should be kept below 45 mph. Extended high-speed
operation in Four-Wheel-Drive Low 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 3 mph (5 km/h) with
the transmission in N (Neutral). The preferred method
for shifting into Four-Wheel-Drive Low is to have
the vehicle moving 1 to 2 mph (1.6 to 3.2 km/h).
Turn the knob to the Four-Wheel-Drive Low position.
You must wait for the Four-Wheel-Drive Low 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 the vehicle, always wait for the mode
indicator lights to stop ashing before shifting the
transmission into gear.
2-47

Parking Brake
For vehicles with a release handle, set the parking
brake by holding the regular brake pedal down,
then pushing down the parking brake pedal.If the ignition is on, the brake system warning light
will come on. SeeBrake System Warning Light
on page 3-42.
A chime sounds and the warning light ashes when the
parking brake is applied and the vehicle is moving at
least 5 mph (8 km/h).
To release the parking brake, hold the regular brake
pedal down. Then pull the bottom edge of the lever with
the parking brake symbol, located above the parking
brake pedal.
If the ignition is on when the parking brake is released,
the brake system warning light goes off.
Notice:Driving with the parking brake on can
overheat the brake system and cause premature
wear or damage to brake system parts. Make sure
that the parking brake is fully released and the brake
warning light is off before driving.
If you are towing a trailer and are parking on any hill,
seeTowing a Trailer on page 4-53.
2-50

For vehicles without a release handle, set the parking
brake by holding the regular brake pedal down,
then pushing down the parking brake pedal.If the ignition is on, the brake system warning light
will come on. SeeBrake System Warning Light
on page 3-42.
Notice:Driving with the parking brake on can
overheat the brake system and cause premature
wear or damage to brake system parts. Make sure
that the parking brake is fully released and the brake
warning light is off before driving.
To release the parking brake, hold the regular brake
pedal down, then push down momentarily on the parking
brake pedal until you feel the pedal release. Slowly
pull your foot up off the park brake pedal. If the parking
brake is not released when you begin to drive, the
brake system warning light will ash and a chime will
sound warning you that the parking brake is still on.
If you are towing a trailer and are parking on a hill,
seeTowing a Trailer on page 4-53.
2-51

Shifting Into Park
{CAUTION:
It can be dangerous to get out of the vehicle if the
shift lever is not fully in P (Park) with the parking
brake rmly set. The vehicle can roll. If you have
left the engine running, the vehicle can move
suddenly. You or others could be injured. To be
sure the vehicle will not move, even when you are
on fairly level ground, use the steps that follow.
With four-wheel drive, if the transfer case is in
N (Neutral), the vehicle will be free to roll, even if
the shift lever is in P (Park). So, be sure the
transfer case is in a drive gear — not in
N (Neutral). If you are pulling a trailer, seeTowing
a Trailer on page 4-53.
1. Hold the brake pedal down, then set the parking
brake.
SeeParking Brake on page 2-50for more
information.
2. Move the shift lever into the P (Park) position by
pulling the shift lever toward you and moving it up
as far as it will go.3. Be sure the transfer case is in a drive gear — not
in N (Neutral).
4. Turn the ignition key to LOCK/OFF.
5. Remove the key and take it with you. If you can
leave the vehicle with the ignition key in your
hand, the vehicle is in P (Park).
Leaving the Vehicle With the Engine
Running
{CAUTION:
It can be dangerous to leave the vehicle with the
engine running. The vehicle could move suddenly
if the shift lever is not fully in P (Park) with the
parking brake rmly set.
If you have four-wheel drive and the transfer case is
in N (Neutral), the vehicle will be free to roll, even if
the shift lever is in P (Park). So be sure the transfer
case is in a drive gear — not in N (Neutral).
CAUTION: (Continued)
2-52

Running the Vehicle While Parked
It is better not to park with the engine running. But if you
ever have to, here are some things to know.
{CAUTION:
Idling a vehicle in an enclosed area with poor
ventilation is dangerous. Engine exhaust may
enter the vehicle. Engine exhaust contains Carbon
Monoxide (CO) which cannot be seen or smelled.
It can cause unconsciousness and even death.
Never run the engine in an enclosed area that has
no fresh air ventilation. For more information,
seeEngine Exhaust on page 2-55.
{CAUTION:
It can be dangerous to get out of the vehicle if
the automatic transmission shift lever is not fully
in P (Park) with the parking brake rmly set.
CAUTION: (Continued)
CAUTION: (Continued)
The vehicle can roll. Do not leave the vehicle when
the engine is running unless you have to. If you
have left the engine running, the vehicle can move
suddenly. You or others could be injured. To be
sure the vehicle will not move, even when you are
on fairly level ground, always set the parking brake
and move the shift lever to P (Park).
{CAUTION:
Four-wheel drive vehicles with the transfer case in
N (Neutral) will allow the vehicle to roll, even if the
automatic transmission shift lever is in P (Park). So,
be sure the transfer case is in a drive gear — not in
N (Neutral). Always set the parking brake.
Follow the proper steps to be sure the vehicle will not
move. SeeShifting Into Park on page 2-52.
If pulling a trailer, seeTowing a Trailer on page 4-53.
2-56