NOTE: If the ignition switch is left in the ACC or RUN
(engine not running) position and the transmission is in
PARK, the system will automatically time out after 30
minutes of inactivity and the ignition will switch to the
OFF position.
Idle Shutdown — 6.4L Engine Only
This feature can be enabled so that the truck will automati-
cally shutdown when the truck has been idling for a set
period of time when the engine is at operating tempera-
ture. Idle time can be set in 5 minute increments between 5
and 60 minutes. See your local authorized dealer to enable
this feature.
NOTE: The idle shut down timer is disabled while the PTO
is active.
ENGINE START/STOP Button Functions — With
Driver ’s Foot OFF The Brake Pedal (In PARK Or
NEUTRAL Position)
The ENGINE START/STOP button operates similar to an
ignition switch. It has three positions, OFF, ACC, RUN. To
change the ignition switch positions without starting the
vehicle and use the accessories follow these steps:
1. Starting with the ignition in the OFF position: 2. Push the ENGINE START/STOP button once to change
the ignition to the ACC position.
3. Push the ENGINE START/STOP button a second time
to change the ignition to the RUN position.
4. Push the ENGINE START/STOP button a third time to
return the ignition to the OFF position.
Extreme Cold Weather (Below –20°F or 29°C)
To ensure reliable starting at these temperatures, use of an
externally powered electric engine block heater (available
from your authorized dealer) is recommended.
If Engine Fails To Start
If the engine fails to start after you have followed the
“Normal Starting” procedure, it may be flooded. Push the
accelerator pedal all the way to the floor and hold it there
while the engine is cranking. This should clear any excess
fuel in case the engine is flooded.
The starter motor will engage automatically, run for 10
seconds, and then disengage. Once this occurs, release the
accelerator pedal and the brake pedal, wait 10 to 15
seconds, then repeat the “Normal Starting” procedure. 5STARTING AND OPERATING 323
It includes a removable cap that is secured by a tethered
strap. It also has a c-clip that is used for storage when not in
use for the Winter months. During Winter months, remove
the heater cord wiring assembly from itself on the c-clip.
The engine block heater must be plugged in at least one
hour to have an adequate warming effect on the engine.
WARNING!Remember to disconnect the engine block heater cord
before driving. Damage to the 110-115 Volt electrical
cord could cause electrocution.
AUTOMATIC TRANSMISSION
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.
WARNING!• 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
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 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 un-
wanted movement. (Continued) 5STARTING AND OPERATING 325
WARNING! (Continued)• 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 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 leav-
ing 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
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. (Continued) WARNING! (Continued)• 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.
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.326 STARTING AND OPERATING
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 turned to
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
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 (refer to “Electronic Range Select [ERS] Operation”
in this section for further information). 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. Some models will display both the selected gear
limit, and the actual current gear, while in ERS mode.
Gear Ranges
DO NOT race the engine when shifting from PARK or
NEUTRAL into another gear range. 5STARTING AND OPERATING 327
WARNING! (Continued)• 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 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
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 (Continued) WARNING! (Continued)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 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. 5STARTING AND OPERATING 329
• 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 leave the vehicle.
WARNING!Do not coast in NEUTRAL and never turn off the
ignition to coast down a hill. These are unsafe practices
that limit your response to changing traffic or road
conditions. You might lose control of the vehicle and
have a collision. CAUTION!Towing the vehicle, coasting, or driving for any other
reason with the transmission in NEUTRAL can cause
severe transmission damage. Refer to “Recreational
Towing” in “Starting And Operating” and “Towing A
Disabled Vehicle” in “What To Do In Emergencies” for
further information.
DRIVE (D)
This range should be used for most city and highway
driving. It provides the smoothest upshifts and downshifts,
and the best fuel economy. The transmission automatically
upshifts through underdrive first, second, and third gears,
direct fourth gear and overdrive fifth and sixth gears. The
DRIVE position provides optimum driving characteristics
under all normal operating conditions.
When frequent transmission shifting occurs (such as when
operating the vehicle under heavy loading conditions, in
hilly terrain, traveling into strong head winds, or while
towing a heavy trailer), use the Electronic Range Select
(ERS) shift control (refer to “Electronic Range Select (ERS)
Operation” in this section for further information) to select
a lower gear range. Under these conditions, using a lower330 STARTING AND OPERATING
gear range will improve performance and extend transmis-
sion life by reducing excessive shifting and heat buildup.
If the transmission temperature exceeds normal operating
limits, the powertrain controller will modify the transmis-
sion shift schedule and expand the range of torque con-
verter clutch engagement. This is done to prevent trans-
mission damage due to overheating.
If the transmission becomes extremely hot or is in danger
of overheating, the “Transmission Temperature Warning
Light” may illuminate and the transmission may operate
differently until the transmission cools down.
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 sig-
nificant additional heat load on the cooling system. Down-
shifting 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. 5STARTING AND OPERATING 331
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.
2. Shift the transmission into PARK.
3. Turn the ignition to the OFF position.
4. Wait approximately 10 seconds. 5. Restart the engine.
6. Shift into the desired gear range. If the problem is no
longer detected, the transmission will return to normal
operation.
NOTE: Even if the transmission can be reset, we recom-
mend that you visit your authorized dealer at your earliest
possible convenience. Your authorized dealer has diagnos-
tic equipment to determine if the problem could recur.
If the transmission cannot be reset, authorized dealer
service is required.
Electronic Range Select (ERS) Operation
The Electronic Range Select (ERS) shift control allows the
driver to limit the highest available gear when the trans-
mission is in DRIVE. For example, if you set the transmis-
sion gear limit to 4 (fourth gear), the transmission will not
shift above fourth gear, but will shift through the lower
gears normally.
You can switch between DRIVE and ERS mode at any
vehicle speed. When the gear selector is in the DRIVE
position, the transmission will operate automatically, shift-
ing between all available gears. Tapping the ERS (-) switch
will activate ERS mode, display the current gear in the332 STARTING AND OPERATING