Page 410 of 675

LOCK/OFF position, and the transmission is locked in
PARK whenever the ignition switch is in the LOCK/OFF
position.
NOTE: If a malfunction occurs, the system will trap the
Key Fob in the ignition switch 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 gear selector in
PARK unless the brakes are applied. To shift the trans-
mission out of PARK, the ignition must be turned to the
ON/RUN position (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.408 STARTING AND OPERATING
Page 415 of 675

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 down-
shifts, 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 driv-
ing characteristics under all normal operating conditions.
When frequent transmission shifting occurs (such as
when operating the vehicle under heavy loading condi-
tions, in hilly terrain, traveling into strong head winds, or
while towing heavy trailers), use the Electronic Range
Select (ERS) shift control (refer to “Electronic Range
Select (ERS) Operation” in this section for further infor-
mation) to select a lower gear range. Under these condi-
tions, using a lower gear range will improve performance
and extend transmission life by reducing excessive shift-
ing and heat buildup. 5STARTING AND OPERATING 413
Page 418 of 675

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
transmission is in DRIVE. For example, if you set the
transmission gear limit to 4 (fourth gear), the transmis-
sion 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,
shifting between all available gears. Tapping the ERS (-)
switch 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 (-) or (+) will
change the top available gear. To exit ERS mode, simply push and hold the ERS (+)
switch until the gear limit display disappears from the
instrument cluster. Column Gear Selector416 STARTING AND OPERATING
Page 419 of 675

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.
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.
CAUTION!When using ERS for engine braking while descend-
ing steep grades, be careful not to overspeed the
engine. Apply the brakes as needed to prevent en-
gine overspeed. Overdrive Operation
The automatic transmission includes an electronically
controlled Overdrive (fifth and sixth gears). The trans-
mission 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 tem-
perature.
• The engine coolant has reached an adequate tempera-
ture.
• Vehicle speed is sufficiently high.
• The TOW/HAUL switch has not been activated.
• The driver is not heavily pressing the accelerator. 5STARTING AND OPERATING 417
Page 420 of 675
When To Use TOW/HAUL Mode
When driving in hilly areas, towing a trailer, carrying a
heavy load, etc., and frequent transmission shifting oc-
curs, push the TOW/HAUL switch to activate TOW/
HAUL mode. This will improve performance and reduce
the potential for transmission overheating or failure due
to excessive shifting. When operating in TOW/HAUL
mode, transmission upshifts are delayed, and the trans-
mission will automatically downshift (for engine brak-
ing) when the throttle is closed and/or during steady
braking maneuvers.
The “TOW/HAUL Indicator Light” will illuminate in the
instrument cluster to indicate that TOW/HAUL mode
has been activated. Pushing the switch a second time
restores normal operation. Normal operation is always
the default at engine start-up. If TOW/HAUL mode is TOW/HAUL Switch418 STARTING AND OPERATING
Page 421 of 675

desired, the switch must be pushed each time the engine
is started.
WARNING!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 possi-
bly resulting in personal injury or death.
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 automati-
cally 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 accelerations, the clutch automatically disengages.
NOTE:
• The torque converter clutch will not engage (and
66RFE-equipped trucks will not shift to sixth gear),
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 con-
verter 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.
• If the vehicle has not been driven for several days, the
first few seconds of operation after shifting the trans-
mission into gear may seem sluggish. This is due to the
fluid partially draining from the torque converter into 5STARTING AND OPERATING 419
Page 422 of 675

the transmission. This condition is normal and will not
cause damage to the transmission. The torque con-
verter will refill within five seconds after starting the
engine.
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 aftermar-
ket 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 com-
mercial vehicle menu on the EVIC/DID 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.
Stationary Mode
To operate the PTO in this mode the vehicle must meet
the following conditions:
• Be in PARK position (vehicles equipped with auto-
matic transmission.)
• PTO switch has been activated.
• Parking brake applied (vehicles equipped with
manual transmission).
• Brake pedal must not be applied.420 STARTING AND OPERATING
Page 423 of 675

• Vehicle engine must be running.
• No vehicle, brake or clutch switch faults present.
• PTO must be correctly installed using the vehicle
provided circuits.
The Electronic Vehicle Information Center (EVIC) or
Driver Information Display (DID) will display a PTO
On message for five seconds if the above conditions are
met. Otherwise, the EVIC/DID 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 oper-
ate 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 operation 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 desir-
able 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 manufacturer to ensure that their electrical (switches 5STARTING AND OPERATING 421