2009 GMC SIERRA 1500 automatic transmission

Tow/Haul Mode (Allison Transmission®
or Hydra-Matic®6-Speed Automatic
Transmission)
Vehicles with an Allison or Hydra-Matic®6-speed
automatic transmission®have a tow/haul mode.
The tow/haul mode adjusts the transmission shift pattern
to reduce shift cycling, providing increased performance,
vehicle control, and transmission cooling when towing
or hauling heavy loads.Turn the tow/haul mode on and off by pressing the
button, located on the end of the shift lever. When the
tow/haul is on, a light on the instrument panel cluster
will come on.
SeeTow/Haul Mode Light on page 3-51for more
information.
Also see “Tow Haul Mode” underTowing a Trailer on
page 4-53for more information.
2-35

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

{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

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

The main components of the instrument panel are the following:
A.Outlet Adjustment on page 3-33.
B.Turn Signal/Multifunction Lever on page 3-9.
C.Driver Information Center (DIC) on page 3-53.
D.Hazard Warning Flashers on page 3-8.
E.Instrument Panel Cluster (US-Canada) on page 3-34.
F. Shift Lever. SeeAutomatic Transmission
Operation on page 2-28. Tow/Haul Selector
Button (If Equipped). SeeTow/Haul Mode on
page 2-34. Range Selection Mode (Allison
Transmission and Hydra-Matic
®6-Speed Button
(If Equipped). SeeAutomatic Transmission Operation
on page 2-28.
G.Audio System(s) on page 3-84.
H.Instrument Panel Storage on page 2-81.
I. Integrated Trailer Brake Controller (If Equipped).
SeeTowing a Trailer on page 4-53.
J.Exterior Lamps on page 3-16.
K.Hood Release on page 5-14.
L.Parking Brake on page 2-50.
M.Dome Lamp Override on page 3-20.Dome Lamps on
page 3-20.Fog Lamps on page 3-19(If Equipped).
N.Cruise Control on page 3-12.
O.Tilt Wheel on page 3-8.P.Horn on page 3-8.
Q.Audio Steering Wheel Controls on page 3-140
(If Equipped).
R. Automatic Transfer Case Control (If Equipped).
SeeFour-Wheel Drive on page 2-37.
S. Ashtray (If Equipped). SeeAshtray(s) and Cigarette
Lighter on page 3-23.
T.StabiliTrak
®System on page 4-6(If Equipped).
Ultrasonic Rear Parking Assist (URPA) on page 2-61
(If Equipped). Pedal Adjust Button (If Equipped).
SeeAdjustable Throttle and Brake Pedal on
page 2-26. Heated Windshield Washer Fluid Button
(If Equipped).Windshield Washer on page 3-12.
U.Accessory Power Outlet(s) on page 3-22.
V.Climate Control System (With Heater Only) on
page 3-24orClimate Control System (With Air
Conditioning) on page 3-25andDual Automatic
Climate Control System on page 3-27.
W. Power Take Off (PTO) Control (If Equipped).
See Power Take Off (PTO) in the Duramax
Diesel Supplement Index.
X. Passenger Airbag Off Control (If Equipped).
SeeAirbag Off Switch on page 1-81.
Y.Glove Box on page 2-80.
3-5

The main components of the instrument panel are the following:
A.Outlet Adjustment on page 3-33.
B.Turn Signal/Multifunction Lever on page 3-9.
C.Instrument Panel Cluster (US-Canada) on page 3-34.
D.Hazard Warning Flashers on page 3-8.
E. Shift Lever. SeeAutomatic Transmission Operation
on page 2-28.
F.Tow/Haul Mode on page 2-34(If Equipped).
G.Driver Information Center (DIC) on page 3-53.
H.Audio System(s) on page 3-84.
I.Exterior Lamps on page 3-16.
J. Integrated Trailer Brake Controller (If Equipped).
SeeTowing a Trailer on page 4-53.
K.Dome Lamp Override on page 3-20.Dome Lamps
on page 3-20.
L. Automatic Transfer Case Control. (If Equipped).
SeeFour-Wheel Drive on page 2-37.
M.Hood Release on page 5-14.
N.Parking Brake on page 2-50.
O.Cruise Control on page 3-12.P.Tilt Wheel on page 3-8.
Q.Horn on page 3-8.
R.Audio Steering Wheel Controls on page 3-140.
S.Climate Control System (With Heater Only)
on page 3-24orClimate Control System (With Air
Conditioning) on page 3-25orDual Automatic
Climate Control System on page 3-27(If Equipped).
T.Accessory Power Outlet(s) on page 3-22. Cigarette
Lighter (If Equipped). SeeAshtray(s) and Cigarette
Lighter on page 3-23.
U.StabiliTrak
®System on page 4-6(If Equipped). Pedal
Adjust Button (If Equipped). SeeAdjustable Throttle
and Brake Pedal on page 2-26.Ultrasonic Rear
Parking Assist (URPA) on page 2-61(If Equipped).
Heated Windshield Washer Fluid Button (If
Equipped). SeeWindshield Washer on page 3-12.
V. Passenger Airbag Off Control (If Equipped).
SeeAirbag Off Switch on page 1-81.
W.Glove Box on page 2-80.
3-7

With cruise control, a speed of about 25 mph (40 km/h)
or more can be maintained without keeping your foot
on the accelerator. Cruise control does not work
at speeds below about 25 mph (40 km/h).
When the brakes are applied, cruise control is
turned off.
For vehicles with an Allison
®or Hydra-Matic 6-speed
automatic transmission, see “Grade Braking and Cruise
Grade Braking (Allison Transmission) underTow/Haul
Mode on page 2-34for an explanation of how cruise
control interacts with the Range Selection Mode, tow/haul
and grade braking systems.
For vehicles with the StabiliTrak
®system that begins
to limit wheel spin while you are using cruise control,
the cruise control will automatically disengage. See
StabiliTrak
®System on page 4-6. When road conditions
allow the cruise control to be safely used again, it can be
turned back on.The cruise control buttons
are located on left side of
the steering wheel.
T(On/Off):Turns the system on or off. The indicator
light is on when cruise control is on and turns off
when cruise control is off.
+ RES (Resume/Accelerate):Press to make the
vehicle accelerate or resume to a previously set speed.
SET−(Set/Coast):Press to set the speed or make
the vehicle decelerate.
[(Cancel):Press to cancel cruise control without
erasing the set speed from memory.
3-13

;(Parking Lamps):Turns on the parking lamps
together with the following:
Instrument Panel Lights
Taillamps
License Plate Lamps
2(Headlamps):Turns on the headlamps together
with the following:
Parking Lamps
Instrument Panel Lights
Taillamps
License Plate Lamps
When the headlamps are turned on while the vehicle is
on, the headlamps turn off automatically 10 minutes after
the ignition is turned off. When the headlamps are turned
on while the vehicle is off, the headlamps will stay on for
10 minutes before automatically turning off to prevent the
battery from being drained. Turn the headlamp control to
off and then back to the headlamp on position to make
the headlamps stay on for an additional 10 minutes.
Push the turn signal/multifunction lever toward the
instrument panel to change the headlamps from low
beam to high beam.
Headlamps on Reminder
A reminder chime will sound when the headlamps or
parking lamps are manually turned on and the ignition
is off and a door is open. To disable the chime, turn the
light off.
Daytime Running Lamps (DRL)
Daytime Running Lamps (DRL) can make it easier for
others to see the front of your vehicle during the day.
Fully functional daytime running lamps are required on
all vehicles rst sold in Canada.
The DRL system will come on when the following
conditions are met:
The ignition is on.
The exterior lamps control is in AUTO.
The transmission is not in P (Park).
The light sensor determines it is daytime.
When the DRL are on, only the DRL lamps will be on.
The taillamps, sidemarker, instrument panel lights,
and other lamps will not be on.
When it begins to get dark, the automatic headlamp
system will switch from DRL to the headlamps.
To turn off the DRL lamps, turn the exterior lamps control
to the OFF position and then release. For vehicles rst
sold in Canada, the transmission must be in the P (Park)
position, before the DRL lamps can be turned off.
3-17