CAUTION!
Damage to the transmission may occur if the following
precautions are not observed:
•Shift into or out of PARK or REVERSE only after the
vehicle has come to a complete stop.
• Do not shift between PARK, REVERSE, NEUTRAL,
or DRIVE when the engine is above idle speed.
• Before shifting into any gear, make sure your foot is
firmly pressing the brake pedal.
NOTE: You must press and hold the brake pedal while
shifting out of PARK.
Key Ignition Park Interlock
This vehicle is equipped with a Key Ignition Park Interlock
which requires the transmission to be in PARK before the
ignition can be turned to the LOCK/OFF (key removal)
position. The key fob can only be removed from the
ignition when the ignition is in the LOCK/OFF position,
and the transmission is locked in PARK whenever the
ignition is in the LOCK/OFF position. NOTE:
If a malfunction occurs, the system will trap the
key fob in the ignition to warn you that this safety feature
is inoperable. The engine can be started and stopped but
the key fob cannot be removed until you obtain service.
Brake/Transmission Shift Interlock System
This vehicle is equipped with a Brake Transmission Shift
Interlock system (BTSI) that holds the transmission gear
selector in PARK unless the brakes are applied. To shift the
transmission out of PARK, the ignition must be in the
ON/RUN mode (engine running or not) and the brake
pedal must be pressed.
Six–Speed Automatic Transmission — If Equipped
Chassis Cab models (with automatic transmission) may
use either the AS66RC transmission (which is equipped
with a Power Take-Off (PTO) access cover on the side of the
transmission case), or the 66RFE transmission (which has
no PTO access cover).
The transmission gear position display (located in the
instrument cluster) indicates the transmission gear range.
The gear selector is mounted on the right side of the
steering column. You must press the brake pedal to move
the gear selector out of PARK (refer to “Brake/
Transmission Shift Interlock System” in this section). To
248 STARTING AND OPERATING
drive, move the gear selector from PARK or NEUTRAL to
the DRIVE position. Pull the gear selector toward you
when shifting into REVERSE or PARK, or when shifting
out of PARK.
The electronically-controlled transmission provides a pre-
cise shift schedule. The transmission electronics are self-
calibrating; therefore, the first few shifts on a new vehicle
may be somewhat abrupt. This is a normal condition, and
precision shifts will develop within a few hundred miles
(kilometers).
Only shift from DRIVE to PARK or REVERSE when the
accelerator pedal is released and the vehicle is stopped. Be
sure to keep your foot on the brake pedal when shifting
between these gears.
The transmission gear selector has only PARK, REVERSE,
NEUTRAL, and DRIVE shift positions. Manual downshifts
can be made using the Electronic Range Select (ERS) shift
control. Pushing the ERS (-/+) switches (on the gear
selector) while in the DRIVE position will select the highest
available transmission gear, and will display that gear limit
in the instrument cluster as 1, 2, 3, etc. Refer toElectronic
Range Select (ERS) Operation in this section for further
information. Some models will display both the selected
gear limit, and the actual current gear, while in ERS mode.Gear Ranges
Do not depress the accelerator pedal when shifting from
PARK or NEUTRAL into another gear range.
NOTE: After selecting any gear range, wait a moment to
allow the selected gear to engage before accelerating. This
is especially important when the engine is cold.
PARK (P)
This range supplements the parking brake by locking the
transmission. The engine can be started in this range.
Never attempt to use PARK while the vehicle is in motion.
Apply the parking brake when exiting the vehicle in this
range.
When parking on a level surface, you may shift the
transmission into PARK first, and then apply the parking
brake.
When parking on a hill, apply the parking brake before
shifting the transmission to PARK, otherwise the load on
the transmission locking mechanism may make it difficult
to move the gear selector out of PARK. As an added
precaution, turn the front wheels toward the curb on a
downhill grade and away from the curb on an uphill grade.
6
STARTING AND OPERATING 249
NOTE:On four-wheel drive vehicles be sure that the
transfer case is in a drive position.
When exiting the vehicle, always:
• Apply the parking brake.
• Shift the transmission into PARK.
• Turn the engine OFF.
• Remove the key fob.
WARNING!
•Never use the PARK position as a substitute for the
parking brake. Always apply the parking brake fully
when exiting the vehicle to guard against vehicle
movement and possible injury or damage.
• Your vehicle could move and injure you and others if
it is not in PARK. Check by trying to move the gear
selector out of PARK with the brake pedal released.
Make sure the transmission is in PARK before exit-
ing the vehicle.
• It is dangerous to shift out of PARK or NEUTRAL if
the engine speed is higher than idle speed. If your
foot is not firmly pressing the brake pedal, the
(Continued)
WARNING! (Continued)
vehicle could accelerate quickly forward or in re-
verse. You could lose control of the vehicle and hit
someone or something. Only shift into gear when the
engine is idling normally and your foot is firmly
pressing the brake pedal.
• Unintended movement of a vehicle could injure
those in or near the vehicle. As with all vehicles, you
should never exit a vehicle while the engine is
running. Before exiting a vehicle, always come to a
complete stop, then apply the parking brake, shift
the transmission into PARK, turn the engine OFF,
and remove the key fob. When the ignition is in the
LOCK/OFF (key removal) position (or, with Keyless
Enter-N-Go, when the ignition is in the OFF mode),
the transmission is locked in PARK, securing the
vehicle against unwanted movement.
• When leaving the vehicle, always make sure the
ignition is in the OFF mode, remove the key fob from
the vehicle, and lock the vehicle.
• Never leave children alone in a vehicle, or with
access to an unlocked vehicle. Allowing children to
be in a vehicle unattended is dangerous for a number
(Continued)
250 STARTING AND OPERATING
WARNING!(Continued)
of reasons. A child or others could be seriously or
fatally injured. Children should be warned not to
touch the parking brake, brake pedal or the trans-
mission gear selector.
• Do not leave the key fob in or near the vehicle (or in
a location accessible to children), and do not leave
the ignition (in a vehicle equipped with Keyless
Enter-N-Go) in the ACC or ON/RUN mode. A child
could operate power windows, other controls, or
move the vehicle.
CAUTION!
• Before moving the transmission gear selector out of
PARK, you must turn the ignition to the ON/RUN
mode, and also press the brake pedal. Otherwise,
damage to the gear selector could result.
• DO NOT race the engine when shifting from PARK
or NEUTRAL into another gear range, as this can
damage the drivetrain. The following indicators should be used to ensure that you
have properly engaged the transmission into the PARK
position:
•
When shifting into PARK, pull the gear selector toward
you and move it all the way counterclockwise until it
stops.
• Release the gear selector and make sure it is fully seated
in the PARK gate.
• Look at the transmission gear position display and
verify that it indicates the PARK position (P).
• With brake pedal released, verify that the gear selector
will not move out of PARK.
REVERSE (R)
This range is for moving the vehicle backward. Shift into
REVERSE only after the vehicle has come to a complete
stop.
NEUTRAL (N)
Use this range when the vehicle is standing for prolonged
periods with the engine running. The engine may be
started in this range. Apply the parking brake and shift the
transmission into PARK if you must exit the vehicle.
6
STARTING AND OPERATING 251
NOTE:Use caution when operating a heavily loaded vehicle
at low speeds (such as towing a trailer up a steep grade, or in
stop-and-go traffic) during hot weather. In these conditions,
torque converter slip can impose a significant additional heat
load on the cooling system. Downshifting the transmission to
the lowest possible gear (when climbing a grade), or shifting
to NEUTRAL (when stopped in heavy traffic) can help to
reduce this excess heat generation.
During cold temperatures, transmission operation may be
modified depending on engine and transmission tempera-
ture as well as vehicle speed. This feature improves warm
up time of the engine and transmission to achieve maxi-
mum efficiency. Engagement of the torque converter clutch
is inhibited until the transmission fluid is warm (refer to
the “Note” under “Torque Converter Clutch” in this sec-
tion).
On models with 66RFE transmission, top overdrive gear is
also inhibited until the transmission fluid is warm, and
during extremely cold temperatures (-16°F [-27°C] or be-
low), operation may briefly be limited to first and direct
gears only. On trucks with AS66RC transmission, fifth and
sixth gears may be inhibited briefly on cold starts below
41°F (5°C), and during very cold temperatures (-4°F [-20°C]
or below), operation may briefly be limited to third gear only. During this condition, the ability of the vehicle to
accelerate under heavily loaded conditions may be re-
duced. In all cases, normal operation will resume once the
transmission temperature has risen to a suitable level.
Transmission Limp Home Mode
Transmission function is monitored electronically for ab-
normal conditions. If a condition is detected that could
result in transmission damage, Transmission Limp Home
Mode is activated. In this mode, the transmission remains
in fourth gear (for 66RFE transmission) or third gear (for
AS66RC transmission) regardless of which forward gear is
selected. If an AS66RC equipped truck enters Limp Home
Mode at highway speeds, it will initially engage fifth gear,
until the vehicle slows to a speed where third gear can be
engaged. PARK, REVERSE, and NEUTRAL will continue
to operate. The Malfunction Indicator Light (MIL) may be
illuminated. Limp Home Mode allows the vehicle to be
driven to an authorized dealer for service without damag-
ing the transmission.
In the event of a momentary problem, the transmission can
be reset to regain all forward gears by performing the
following steps:
1. Stop the vehicle.
6
STARTING AND OPERATING 253
4L
Four-Wheel Drive Low Range — This range locks the front
and rear driveshafts together forcing the front and rear
wheels to rotate at the same speed. Additional traction and
maximum pulling power for loose, slippery road surfaces
only. Do not exceed 25 mph (40 km/h).
This transfer case is intended to be driven in the 2H
position for normal street and highway conditions such as
dry, hard surfaced roads.
When additional traction is required, the 4H and 4L
positions can be used to lock the front and rear driveshafts
together and force the front and rear wheels to rotate at the
same speed. This is accomplished by simply moving the
gear selector to the desired positions once the appropriate
speed and gear requirements are met, refer to “Shifting
Procedure – Manually Shifted Transfer Case” in this section
for further information.
The 4H and 4L positions are intended for loose, slippery
road surfaces only. Driving in the 4H and 4L positions on
dry, hard surfaced roads may cause increased tire wear and
damage to the driveline components.
The “Transfer Case Position Indicator Light” in the instru-
ment cluster will alert the driver that the vehicle is infour-wheel drive and that the front and rear driveshafts are
locked together. This light will illuminate when the transfer
case is shifted into either the 4H or 4L position. There is no
light for the 2H or NEUTRAL positions on some models.
When operating your vehicle in 4L, the engine speed is
approximately three times that of the 2H or 4H positions at
a given road speed. Take care not to overspeed the engine
and do not exceed 25 mph (40 km/h).
Proper operation of four-wheel drive vehicles depends on
tires of equal size, type and circumference on each wheel.
Any difference will adversely affect shifting and can cause
damage to the drivetrain.
NOTE:
Do not attempt to make a shift while only the front
or rear wheels are spinning, as this can cause damage to
driveline components.
Because four-wheel drive provides improved traction,
there is a tendency to exceed safe turning and stopping
speeds. Do not go faster than road conditions permit.
NOTE: Delayed shifts out of four-wheel drive may be
experienced due to uneven tire wear, low or uneven tire
pressures, excessive vehicle loading, or cold temperatures.
258 STARTING AND OPERATING
WARNING!
You or others could be injured or killed if you leave the
vehicle unattended with the transfer case in the NEU-
TRAL position without first fully engaging the park-
ing brake. The transfer case NEUTRAL position disen-
gages both the front and rear drive shafts from the
powertrain and will allow the vehicle to roll, even if
the transmission is in PARK. The parking brake
should always be applied when the driver is not in the
vehicle.
Two-Wheel Drive High Range (2H)
Rear-Wheel Drive High Range — This range is for normal
street and highway driving on dry hard surfaced roads.
Four-Wheel Drive High Range (4H)
Four-Wheel Drive High Range — This range locks the front
and rear driveshafts together forcing the front and rear
wheels to rotate at the same speed. Additional traction for
loose, slippery road surfaces only.
Neutral (N)
Neutral — This range disengages the front and rear
driveshafts from the powertrain. To be used for flat towingbehind another vehicle. Refer to “Recreational Towing” in
“Starting And Operating” for further information.
Four-Wheel Drive Low Range (4L)
Four-Wheel Drive Low Range — This range locks the front
and rear driveshafts together forcing the front and rear
wheels to rotate at the same speed. Additional traction and
maximum pulling power for loose, slippery road surfaces
only. Do not exceed 25 mph (40 km/h).
CAUTION!
Do not use 4L (Low) range when operating the vehicle
on dry pavement. Driveline hardware damage can
result.
Shifting Procedure — Manually Shifted Transfer
Case
2H To 4H
Shifting between 2H and 4H can be made with the vehicle
stopped or in motion. If the vehicle is in motion, shifts can be
made up to 55 mph (88 km/h). With the vehicle in motion,
the transfer case will engage/disengage faster if you momen-
tarily release the accelerator pedal after completing the shift.
Apply a constant force when shifting the transfer case lever.
6
STARTING AND OPERATING 259
2H Or 4H To 4L
NOTE:When shifting into or out of 4L some gear noise
may be heard. This noise is normal and is not detrimental
to the vehicle or occupants.
With the vehicle rolling at 2 to 3 mph (3 to 5 km/h), shift
the transmission into NEUTRAL. While the vehicle is
coasting at 2 to 3 mph (3 to 5 km/h), shift the transfer case
lever firmly to the desired position. Do not pause in
transfer case NEUTRAL.
NOTE:
•
Pausing in transfer case NEUTRAL in vehicles equipped
with an automatic transmission may require shutting the
engine OFF to avoid gear clash while completing the shift.
If difficulty occurs, shift the transmission into NEUTRAL,
hold your foot on the brake, and turn the engine OFF.
Complete the range shift to the desired mode.
•Shifting into or out of 4L is possible with the vehicle
completely stopped, however difficulty may occur due to
the mating clutch teeth not being properly aligned. Several
attempts may be required for clutch teeth alignment and
shift completion to occur. The preferred method is with
the vehicle rolling 2 to 3 mph (3 to 5 km/h). Avoid
attempting to engage or disengage 4L with the vehicle
moving faster than 2 to 3 mph (3 to 5 km/h).
• Do not attempt to shift into or out of 4L while the
transmission is in gear.
Transfer Case Position Indicator Light
The “Transfer Case Position Indicator Light” in the instru-
ment cluster is used to alert the driver that the front axle is
fully engaged and all four wheels are driving.
Electronically Shifted Transfer Case (Four-Position
Switch) — If Equipped
The electronic shift transfer case is operated by the 4WD
Control Switch (Transfer Case Switch), which is located on
the instrument panel.
Four-Position/Part Time Transfer Case
260 STARTING AND OPERATING