See “Range Selection Mode” later in this section.
P (Park):This position locks the rear wheels. It is the
best position to use when starting the engine because
the vehicle cannot move easily. When parked on a hill,
especially when the vehicle has a heavy load, you might
notice an increase in the effort to shift out of P (Park).
See Torque Lock (Automatic Transmission) under
Shifting Into Park on page 2-52for more information.
{CAUTION:
It is 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.
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). SeeShifting Into
Park on page 2-52. If you are pulling a trailer,
seeTowing a Trailer on page 4-51. Heavy Duty 6-Speed Automatic Transmission
Shown (Light Duty 6 Speed Similar)
2-29
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 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.
Grade Braking is not available when Range Selection
Mode is active. SeeTow/Haul Mode on page 2-34.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 your vehicle has the Allison Transmission®,orthe
Hydra-Matic®6-Speed Automatic Transmission, it has a
Low Traction Mode that can 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 Range Selection Mode. This will limit
torque to the wheels after it detects wheel slip, preventing
the tires from spinning.
2-33
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 andAutomatic
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 4-51for 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
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 4-45
Towing Your Vehicle on page 4-45
Notice: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.
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.
2-38
2m(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.
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.
SeeRecreational Vehicle Towing on page 4-45or
Towing Your Vehicle on page 4-45for 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.
2-42