2019 RAM CHASSIS CAB automatic transmission

STARTING AND OPERATING 269
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 all forward 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), select TOW/HAUL mode or use the
Electronic Range Select (ERS) shift control (refer to "Elec -
tronic Range Select (ERS) Operation" in this section for
further information) to select a lower gear range. Under
these conditions, using a lower gear range will improve
performance and extend transmission life by reducing exces -
sive shifting and heat buildup.
During extremely cold temperatures (-22°F [-30°C] or
below), transmission operation may be modified depending
on engine and transmission temperature as well as vehicle
speed. Normal operation will resume once the transmission
temperature has risen to a suitable level. Transmission Limp Home Mode
Transmission function is monitored electronically for
abnormal conditions. If a condition is detected that could
result in transmission damage, Transmission Limp Home
Mode is activated. In this mode, the transmission may
operate only in certain gears, or may not shift at all. Vehicle
performance may be severely degraded and the engine may
stall. In some situations, the transmission may not re-engage
if the engine is turned off and restarted. The Malfunction
Indicator Light (MIL) may be illuminated. A message in the
instrument cluster will inform the driver of the more serious
conditions, and indicate what actions may be necessary.
In the event of a momentary problem, the transmission can
be reset to regain all forward gears by performing the
following steps:
NOTE:
In cases where the instrument cluster message indicates the
transmission may not re-engage after engine shutdown,
perform this procedure only in a desired location (prefer -
ably, at an authorized dealer).
1. Stop the vehicle.
2. Shift the transmission into PARK, if possible. If not, shift
the transmission to NEUTRAL. 5

270 STARTING AND OPERATING
3. Push and hold the ignition switch until the engine turns
OFF.
4. Wait approximately 30 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 recommend that
you visit an authorized dealer at your earliest possible
convenience. An authorized dealer has diagnostic equip -
ment to assess the condition of your transmission.
If the transmission cannot be reset, authorized dealer service
is required.
Electronic Range Select (ERS) Operation — Eight-Speed
Transmission
The Electronic Range Select (ERS) shift control allows the
driver to limit the highest available gear when the transmis -
sion is in DRIVE. For example, if you set the transmission
gear limit to 4 (fourth gear), the transmission will not shift above fourth gear (except to prevent engine overspeed), but
will shift through the lower gears normally.
You can switch between DRIVE and ERS mode at any
vehicle speed. When the transmission gear selector is in
DRIVE, the transmission will operate automatically, shifting
between all available gears. Tapping the GEAR- switch (on
the steering wheel) will activate ERS mode, display the
current gear in the instrument cluster, and set that gear as the
top available gear. Once in ERS mode, tapping the GEAR- or
GEAR+ switch will change the top available gear.
1 — GEAR + Switch 2 — GEAR – Switch

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

282 STARTING AND OPERATING
Stationary Mode
To operate the PTO in this mode the vehicle must meet the
following conditions:
• Transmission in PARK position.
• PTO switch has been activated.
• Brake pedal must not be applied.
• Vehicle engine must be running.
• No vehicle, or brake faults present.
• PTO must be correctly installed using the vehicle provided
circuits.
The instrument cluster will display a "PTO On" message for
five seconds if the above conditions are met. Otherwise, the
instrument cluster will display a message "To Operate PTO
Shift To Park" indicating what operator action should be
taken to engage the PTO mode.
The customer has the choice to operate the PTO by utilizing
the cruise control switches or by utilizing a remote control
(provided by the PTO supplier). To operate the feature using
the cruise control switches, the customer must first activate
the PTO switch which will turn on the PTO. In order to
increase or decrease the engine idle speed, to optimize the
PTO function, the “RESUME/ACCEL” and “DECEL” cruise switches can be used respectively. To disengage PTO opera -
tion and return to “standard vehicle operation” simply
toggle the PTO switch to the OFF position.
The torque converter clutch (TCC) will automatically engage
at engine speeds above 1,200 RPM (engine speed) in PTO
stationary mode. Once engaged, the TCC will remain
applied and will not disengage until the engine speed falls
below 1,000 RPM. TCC engagement is desirable for certain
types of PTO applications (Automatic Transmission Only).
To operate the PTO via a remote switch, the customer must
make sure the above conditions are met. It is vital for proper
operation that the PTO and remote have been installed
correctly, paying special attention to ensure the vehicle
provided wiring has been connected properly. This is the
responsibility of the installer of the PTO and switches/
remote system. It is the responsibility of the PTO manufac -
turer to ensure that their electrical (switches and remote)
system is compatible with the vehicle’s electrical architecture
and software functionality.
NOTE:
Single set speed can be programmed via the PTO menu on
the instrument cluster display. Further details are available
at the Ram Truck Bodybuilders web site located at rambody -
builder.com

290 STARTING AND OPERATING
Adaptive Cruise Control (ACC) Operation
The speed control buttons (located on the right side of the
steering wheel) operate the ACC system.
Adaptive Cruise Control Buttons
NOTE:
Any chassis/suspension or tire size modifications to the
vehicle will effect the performance of the Adaptive Cruise
Control and Forward Collision Warning System. Activating Adaptive Cruise Control (ACC)
You can only engage ACC if the vehicle speed is above
0 mph (0 km/h).
The minimum set speed for the ACC system is 20 mph
(32 km/h).
When the system is turned on and in the ready state, the
instrument cluster display will read “ACC Ready.”
When the system is off, the instrument cluster display will
read “Adaptive Cruise Control (ACC) Off.”
NOTE:
You cannot engage ACC under the following conditions:
• When in Four-Wheel Drive Low.
• When you apply the brakes.
• When the parking brake is applied.
• When the automatic transmission is in PARK, REVERSE or
NEUTRAL.
• When the vehicle speed is outside of the speed range.
• When the brakes are overheated.1 — Adaptive Cruise Control On/Off Button
2 — Distance Button

STARTING AND OPERATING 353
Seven-Pin Connector
Towing Tips
Before setting out on a trip, practice turning, stopping, and
backing up the trailer in an area located away from heavy
traffic. Automatic Transmission
The DRIVE range can be selected when towing. The trans -
mission controls include a drive strategy to avoid frequent
shifting when towing. However, if frequent shifting does
occur while in DRIVE, select TOW/HAUL mode or select a
lower gear range (using the Electronic Range Select (ERS)
shift control).
NOTE:
Using TOW/HAUL mode or selecting a lower gear range
(using the ERS shift control) while operating the vehicle
under heavy loading conditions will improve performance
and extend transmission life by reducing excessive shifting
and heat build up. This action will also provide better engine
braking.
Six-Speed Automatic Transmission Only
When towing a loaded trailer up steep grades at low speeds
(20 mph [32 km/h] or below), holding your vehicle in first
gear (using the ERS shift control) can help to avoid transmis -
sion overheating.1 — Battery 5 — Ground
2 — Backup Lamps 6 — Left Stop/Turn
3 — Right Stop/Turn 7 — Running Lamps
4 — Electric Brakes 5

354 STARTING AND OPERATING
If you regularly tow a trailer for more than 45 minutes of
continuous operation, then change the automatic transmis -
sion fluid and filter(s) as specified for "police, taxi, fleet, or
frequent trailer towing." Refer to the “Maintenance Plan” for
the proper maintenance intervals.
NOTE:
Check the automatic transmission fluid level before towing
(Six-speed automatic only).
Tow/Haul Mode
To reduce potential for automatic transmission overheating,
activate TOW/HAUL mode when driving in hilly areas, or
select a lower gear range (using the Electronic Range Select
(ERS) shift control) on more severe grades.
Speed Control — If Equipped
• Do not use on hilly terrain or with heavy loads.
• When using the speed control, if you experience speed
drops greater than 10 mph (16 km/h), disengage until you
can get back to cruising speed.
• Use speed control in flat terrain and with light loads to
maximize fuel efficiency. Cooling System
To reduce potential for engine and transmission over -
heating, take the following actions:
City Driving
• In city traffic — while stopped, place the transmission in
NEUTRAL, but do not increase engine idle speed.
Highway Driving
• Reduce speed.
• Temporarily turn off air conditioning.
Air Suspension System
To aid in attaching/detaching the trailer from the vehicle,
the air suspension system can be used. Refer to “Air Suspen -
sion System” in “Starting And Operating” for further infor -
mation.
NOTE:
The vehicle must remain in the engine running position
while attaching a trailer for proper leveling of the air suspen -
sion system.