
STARTING AND OPERATING 263
NOTE:
To select the proper gear position for maximum deceleration
(engine braking), simply push and hold the ERS (-) switch.
The transmission will shift to the range from which the
vehicle can best be slowed down.
Overdrive Operation
The automatic transmission includes an electronically
controlled Overdrive (fifth and sixth gears). The transmis -
sion will automatically shift into Overdrive if the following
conditions are present:
• The gear selector is in the DRIVE position.
• The transmission fluid has reached an adequate temperature. • The engine coolant has reached an adequate temperature.
• Vehicle speed is sufficiently high.
• The TOW/HAUL switch has not been activated.
• The driver is not heavily pressing the accelerator.
Torque Converter Clutch
A feature designed to improve fuel economy has been
included in the automatic transmission on your vehicle. A
clutch within the torque converter engages automatically at
calibrated speeds. This may result in a slightly different
feeling or response during normal operation in the upper
gears. When the vehicle speed drops or during some acceler -
ations, the clutch automatically disengages.
NOTE:
• The torque converter clutch will not engage, until the
transmission fluid and engine coolant are warm [usually
after 1 to 3 miles (2 to 5 km) of driving]. Because engine
speed is higher when the torque converter clutch is not
engaged, it may seem as if the transmission is not shifting
properly when cold. This is normal. Using the Electronic
Range Select (ERS) shift control, when the transmission is
sufficiently warm, will demonstrate that the transmission
is able to shift into and out of Overdrive.WARNING!
Do not downshift for additional engine braking on a
slippery surface. The drive wheels could lose their grip
and the vehicle could skid, causing a collision or
personal injury.
CAUTION!
When using ERS for engine braking while descending
steep grades, be careful not to overspeed the engine.
Apply the brakes as needed to prevent engine overspeed. 5

STARTING AND OPERATING 275
3. When the shift is complete, the indicator light for the
selected position will stop flashing and remain ON.
If One Or More Of The Following Shift Conditions Are
Not Met:
1. The indicator light for the current position will remain
ON.
2. The newly selected position indicator light will continue
to flash.
3. The transfer case will not shift.
NOTE:
Before retrying a selection, make certain that all the neces -
sary requirements for selecting a new transfer case position
have been met. To retry the selection, push the current posi -
tion, wait five seconds, and retry selection. To find the shift
requirements, refer to the "Shifting Procedure" for your
transfer case, located in this section.
The “SVC 4WD Warning Light” monitors the electronic shift
four-wheel drive system. If this light remains on after engine
start up or illuminates during driving, it means that the
four-wheel drive system is not functioning properly and that
service is required. NOTE:
Do not attempt to make a shift while only the front or rear
wheels are spinning. This could cause damage to driveline
components.
When operating your vehicle in 4WD LOW, the engine
speed is approximately three times that of the 2WD or 4WD
HIGH positions at a given road speed. Take care not to over -
speed 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 in tire size can cause damage to the drive -
train.
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. WARNING!
Always engage the parking brake when powering down
the vehicle if the “SVC 4WD Warning Light” is
illuminated. Not engaging the parking brake may allow
the vehicle to roll which may cause personal injury or
death.
5

280 STARTING AND OPERATING
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
momentarily release the accelerator pedal after completing
the shift. Apply a constant force when shifting the transfer
case lever.
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 transmis -
sion 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.

STARTING AND OPERATING 281
LIMITED-SLIP DIFFERENTIAL
The limited-slip differential provides additional traction on
snow, ice, mud, sand and gravel, particularly when there is
a difference between the traction characteristics of the
surface under the right and left rear wheels. During normal
driving and cornering, the limited-slip unit performs simi -
larly to a conventional differential. On slippery surfaces,
however, the differential delivers more of the driving effort
to the rear wheel having the better traction.
The limited-slip differential is especially helpful during slip -
pery driving conditions. With both rear wheels on a slippery
surface, a slight application of the accelerator will supply
maximum traction. When starting with only one rear wheel
on an excessively slippery surface, slight momentary appli -
cation of the parking brake may be necessary to gain
maximum traction. Care should be taken to avoid sudden accelerations when
both rear wheels are on a slippery surface. This could cause
both rear wheels to spin, and allow the vehicle to slide side -
ways on the crowned surface of a road or in a turn.
POWER TAKE OFF OPERATION — IF EQUIPPED
(CHASSIS CAB ONLY)
This vehicle when equipped with PTO Prep and the AS66RC
automatic six-speed, will allow for an aftermarket upfit with
a transmission driven PTO (power take off). The customer
will have the ability to operate the PTO in either a
“stationary” or “mobile” mode. The vehicles will be factory
set to the “stationary” mode. To select “mobile” mode, you
will need to enter the commercial vehicle menu on the instru -
ment cluster screen and select mobile PTO mode. Details of
the PTO selection modes and further PTO information is
available at the Ram Truck Bodybuilders web site:
www.rambodybuilder.com .
AS66RC Six-Speed Automatic Transmission Only
The PTO drive gear (part of the AS66RC) operates at torque
converter turbine speed. The turbine speed will be less than
engine speed when the torque converter clutch is not
engaged and will be same as engine speed when the torque
converter clutch is engaged.WARNING!
On vehicles equipped with a limited-slip differential
never run the engine with one rear wheel off the ground
since the vehicle may drive through the rear wheel
remaining on the ground. You could lose control of the
vehicle. 5

288 STARTING AND OPERATING
To Resume Speed
To resume a previously set speed, push the RES (+) button
and release. Resume can be used at any speed above 20 mph
(32 km/h).
To Deactivate
A soft tap on the brake pedal, pushing the CANCEL button,
or normal brake pressure while slowing the vehicle will
deactivate the Speed Control without erasing the set speed
from memory.
Pushing the On/Off button, or returning the ignition to OFF,
erases the set speed from memory.
ADAPTIVE CRUISE CONTROL (ACC) — IF EQUIPPED
Adaptive Cruise Control (ACC) increases the driving conve -
nience provided by cruise control while traveling on high -
ways and major roadways. However, it is not a safety system
and not designed to prevent collisions. Speed Control func -
tion performs differently. Please refer to the proper section
within this chapter.
ACC will allow you to keep cruise control engaged in light
to moderate traffic conditions without the constant need to
reset your cruise control. ACC utilizes a radar sensor and a forward facing camera designed to detect a vehicle directly
ahead of you.
NOTE:
• If the sensor does not detect a vehicle ahead of you, ACC
will maintain a fixed set speed.
• If the ACC sensor detects a vehicle ahead, ACC will apply
limited braking or accelerate (not to exceed the original set
speed) automatically to maintain a preset following
distance, while matching the speed of the vehicle ahead.
The Cruise Control system has two control modes:
• Adaptive Cruise Control mode for maintaining an appro -
priate distance between vehicles.
• Normal (Fixed Speed) Cruise Control mode for cruising at
a constant preset speed. For additional information, refer
to “Normal (Fixed Speed) Cruise Control Mode” in this
section.
NOTE:
Normal (Fixed Speed) Cruise Control will not react to
preceding vehicles. Always be aware of the mode selected.
You can change the mode by using the Cruise Control
buttons. The two control modes function differently. Always
confirm which mode is selected.

STARTING AND OPERATING 297
Distance Setting 1 Bar (Short)
The system automatically defaults to the longest distance
setting. To decrease the distance setting, push the Distance
Button and release. Each time the button is pushed, the
distance setting decreases by one bar. Once the shortest
setting is reached, if the button is pushed again it will reset
to the default setting (longest).
If there is no vehicle ahead, the vehicle will maintain the set
speed. If a slower moving vehicle is detected in the same
lane, the instrument cluster displays the “Sensed Vehicle
Indicator” icon, and the system adjusts vehicle speed auto -
matically to maintain the distance setting, regardless of the
set speed. The vehicle will then maintain the set distance until:
• The vehicle ahead accelerates to a speed above the set
speed.
• The vehicle ahead moves out of your lane or view of the
sensor.
• The distance setting is changed.
• The system disengages. (Refer to the information on ACC
Activation).
The maximum braking applied by ACC is limited; however,
the driver can always apply the brakes manually, if neces -
sary.
NOTE:
The brake lights will illuminate whenever the ACC system
applies the brakes.
A Proximity Warning will alert the driver if ACC predicts
that its maximum braking level is not sufficient to maintain
the set distance. If this occurs, a visual alert “BRAKE” will
flash in the instrument cluster display and a chime will
sound while ACC continues to apply its maximum braking
capacity. 5

STARTING AND OPERATING 349
Integrated Trailer Brake Module — If Equipped
Your vehicle may have an Integrated Trailer Brake Module
(ITBM) for Electric and Electric Over Hydraulic (EOH) trailer
brakes.
NOTE:
This module has been designed and verified with electric
trailer brakes and new electric over hydraulic systems. Some
previous EOH systems may not be compatible with ITBM.
Integrated Trailer Brake Module (ITBM) The user interface consists of the following:
Manual Brake Control Lever
Slide the manual brake control lever to the left to activate
power to the trailer's electric brakes independent of the tow
vehicle's brakes. If the manual brake control lever is acti -
vated while the brake is also applied, the greater of the two
inputs determines the power sent to the trailer brakes.
The trailer and the vehicle’s stop lamps will come on when
braking normally with the vehicle brake pedal. Only the
trailer stop lamps will come on when the manual brake
control lever is applied.
Trailer Brake Status Indicator Light
This light indicates the trailer electrical connection status.
If no electrical connection is detected after the ignition is
turned on, pushing the GAIN adjustment button or sliding
the manual brake control lever will display the GAIN setting
for 10 seconds and the “Trailer Brake Status Indicator Light”
will not be displayed.
If a fault is detected in the trailer wiring or the Integrated
Trailer Brake Module (ITBM), the “Trailer Brake Status Indi -
cator Light” will flash.1 — GAIN Adjustment Button
2 — GAIN Adjustment Button
3 — Manual Brake Control Lever 5

STARTING AND OPERATING 351
Repeat steps 8 and 9 until the GAIN setting is at a point just below trailer wheel lockup. If towing a heavier trailer, trailer wheel
lockup may not be attainable even with the maximum GAIN setting of 10.
* The suggested selection depends and may change
depending on the customer preferences for braking perfor -
mance. Condition of the trailer brakes, driving and road state
may also affect the selection.
Display Messages
The trailer brake control interacts with the instrument cluster
display. Display messages, along with a single chime, will be
displayed when a malfunction is determined in the trailer
connection, trailer brake control, or on the trailer. Refer to
“Instrument Cluster Display” in “Getting To Know Your
Instrument Panel” for further information. Light Electric Heavy Electric Light EOH Heavy EOH
Type of Trailer Brakes Electric Trailer Brakes Electric Trailer Brakes Electric over Hydraulic
Trailer Brakes Electric over Hydraulic
Trailer Brakes
Load *Under 10,000 lbs *Above 10,000 lbs *Under 10,000 lbs *Above 10,000 lbs
WARNING!
Connecting a trailer that is not compatible with the
ITBM system may result in reduced or complete loss of
trailer braking. There may be a increase in stopping
distance or trailer instability which could result in
personal injury.
CAUTION!
Connecting a trailer that is not compatible with the
ITBM system may result in reduced or complete loss of
trailer braking. There may be a increase in stopping
distance or trailer instability which could result in
damage to your vehicle, trailer, or other property. 5