automatic transmission RAM CHASSIS CAB 2019 User Guide

254 STARTING AND OPERATING
(Continued)(Continued)AUTOMATIC TRANSMISSION
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 reverse. 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.
• The transmission may not engage PARK if the vehicle
is moving. Always bring the vehicle to a complete stop
before shifting to PARK, and verify that the transmis -
sion gear position indicator solidly indicates PARK (P)
without blinking. Ensure that the vehicle is completely
stopped, and the PARK position is properly indicated,
before exiting the vehicle. • 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 igni -
tion is in the OFF mode) the transmission is locked in
PARK, securing the vehicle against unwanted move -
ment.
• When leaving the vehicle, always make sure the igni -
tion 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 move -
ment 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 exiting
the vehicle. WARNING! (Continued)

256 STARTING AND OPERATING
Vehicles With Mechanical Key:
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 OFF (key removal) position. The
key can only be removed from the ignition when the ignition
is in the OFF position, and the transmission is locked in
PARK whenever the ignition is in the OFF position. If the
vehicle's battery becomes discharged, the key will be
trapped in the ignition even when the gear selector is in
PARK. Recharge the battery to allow key removal.
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. For vehicles
with 8-speed transmission, to shift the transmission out of
PARK, the engine must be running and the brake pedal must
be pressed. The brake pedal must also be pressed to shift
from NEUTRAL into DRIVE or REVERSE when the vehicle is stopped or moving at low speeds. For vehicles with
6-speed transmission, 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 may use the AS66RC transmission
(which is equipped with a Power Take-Off (PTO) access
cover on the side of the transmission case).
The transmission gear position display (located in the instru -
ment 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 precise
shift schedule. The transmission electronics are self-cali -
brating; therefore, the first few shifts on a new vehicle may
be somewhat abrupt. This is a normal condition, and preci -
sion shifts will develop within a few hundred miles (kilome -
ters).

260 STARTING AND OPERATING
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 transmis -
sion into PARK if you must exit the vehicle.
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) Opera -
tion” 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 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 converter
clutch engagement. This is done to prevent transmission
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.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 “In Case Of Emergency” for further
information.

262 STARTING AND OPERATING
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 your authorized dealer at your earliest possible
convenience. Your 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
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, 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 posi -
tion, the transmission will operate automatically, shifting
between all available gears. Tapping the ERS (-) switch will activate ERS mode, display the current gear in the instru -
ment cluster, and set that gear as the top available gear. Once
in ERS mode, tapping (-) or (+) will change the top available
gear.
Electronic Range Select
To exit ERS mode, simply push and hold the ERS (+) switch
until the gear limit display disappears from the instrument
cluster. 1 — GEAR + Switch 2 — GEAR – Switch

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 265
Eight-Speed Automatic Transmission
The transmission is controlled using a rotary electronic gear
selector located on the instrument panel. The transmission
gear range (PRND) is displayed both above the gear selector
and in the instrument cluster. To select a gear range, simply
rotate the gear selector. You must press the brake pedal to
shift the transmission out of PARK (or NEUTRAL, when the
vehicle is stopped or moving at low speeds). To shift past
multiple gear ranges at once (such as PARK to DRIVE),
simply rotate the gear selector to the appropriate detent.
Select the DRIVE range for normal driving. NOTE:
In the event of a mismatch between the gear selector position
and the actual transmission gear (for example, driver selects
PARK while driving), the position indicator will blink
continuously until the selector is returned to the proper posi -
tion, or the requested shift can be completed.
The electronically-controlled transmission adapts its shift
schedule based on driver inputs, along with environmental
and road conditions. 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 positions. Manual downshifts can be
made using the Electronic Range Select (ERS) shift control.
Pressing the GEAR-/GEAR+ switches (on the steering
wheel) 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 to “ElectronicWARNING!
Do not use the “TOW/HAUL” feature when driving in
icy or slippery conditions. The increased engine braking
can cause the rear wheels to slide, and the vehicle to
swing around with the possible loss of vehicle control,
which may cause an accident possibly resulting in
personal injury or death.
5

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