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 the
336 STARTING AND OPERATING
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.
WARNING!
Do not downshift for additional engine braking on a
slippery surface. The drive wheels could lose their grip
(Continued)
WARNING!(Continued)
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 descending
steep grades, be careful not to overspeed the engine.
Apply the brakes as needed to prevent engine over-
speed.
Overdrive Operation
The automatic transmission includes an electronically con-
trolled Overdrive (fifth and sixth gears). The transmission
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.
Column Gear Selector
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STARTING AND OPERATING 337
•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.
When To Use TOW/HAUL Mode
When driving in hilly areas, towing a trailer, carrying a
heavy load, etc., and frequent transmission shifting occurs,
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 transmission
will automatically downshift (for engine braking) when the
throttle is closed and/or during steady braking maneu-
vers. 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 desired, the
switch must be pushed each time the engine is started.
TOW/HAUL Switch
338 STARTING AND OPERATING
WARNING!
Do not use the “TOW/HAUL” feature when driving in
icy or slippery conditions. The increased engine brak-
ing 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 result-
ing 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 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
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 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 Over-
drive.
• If the vehicle has not been driven for several days, the
first few seconds of operation after shifting the transmis-
sion into gear may seem sluggish. This is due to the fluid
partially draining from the torque converter into the
transmission. This condition is normal and will not
cause damage to the transmission. The torque converter
will refill within five seconds after starting the engine.
5
STARTING AND OPERATING 339
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 instrument 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.
Stationary Mode
To operate the PTO in this mode the vehicle must meet the
following conditions:•
Transmission in PARK position (vehicles equipped with
automatic transmission.)
• PTO switch has been activated.
• Parking brake applied (vehicles equipped with manual
transmission).
• Brake pedal must not be applied.
• Vehicle engine must be running.
• No vehicle, brake or clutch switch faults present.
• PTO must be correctly installed using the vehicle pro-
vided circuits.
The instrument cluster will display a PTO Onmessage 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
340 STARTING AND OPERATING
“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 en-
gage 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
manufacturer 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 rambodybuilder.comMobile Mode
To operate the PTO in this mode the vehicle must meet the
following conditions:
•Mobile mode is activated via the menu on the instru-
ment cluster display.
• (ON/OFF) switch has been activated.
• Vehicles with automatic transmission must be in PARK
or DRIVE.
• Parking brake must not be applied.
• Brake pedal must not be applied.
• No vehicle, brake or clutch switch faults present.
• Vehicle engine must be running.
• PTO must be correctly installed using the vehicle pro-
vided circuits.
The customer may choose to use the PTO while the vehicle
is moving. To do so, the PTO function must be activated
prior to taking the vehicle out of PARK. This is accom-
plished by activating the upfitter-provided PTO on/off
switch. At this point, the customer may place the vehicle in
a forward or reverse gear and have PTO operation once the
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STARTING AND OPERATING 341
vehicle begins to move. To disengage PTO operation and
return to “standard vehicle operation” simply toggle the
on/off switch to the OFF position.
NOTE:For application specific information with respect
to PTO and pump requirements and additional vehicle
information (wiring schematics, preset idle values, engine
speed limits, and vehicle hardware and software require-
ments) please refer to the Body Builders Guide by access-
ing rambodybuilder.com and choosing the appropriate
links.
FOUR-WHEEL DRIVE OPERATION — IF EQUIPPED
Four-wheel drive trucks are equipped with either a manu-
ally shifted transfer case or an electronically shifted trans-
fer case. Refer to the operating instructions for your
transfer case, located in this section for further information.
Manually Shifted Transfer Case — If Equipped
The transfer case provides four mode positions:
• Two-Wheel Drive High Range (2H)
• Four-Wheel Drive Lock High Range (4H)
• Neutral (N)
• Four-Wheel Drive Low Range (4L) For additional information on the appropriate use of each
transfer case mode position, see the information below:
2H
Two-Wheel Drive High Range — This range is for normal
street and highway driving on dry, hard surfaced roads.
4H
Four-Wheel Drive Lock High Range — This range locks the
front and rear driveshafts together forcing the front and
rear wheels to rotate at the same speed. Additional traction
for loose, slippery road surfaces only.
NEUTRAL (N)
Neutral — This range disengages both the front and rear
driveshafts from the powertrain. To be used for flat towing
behind another vehicle. Refer to “Recreational Towing” in
“Starting And Operating” for further information.
4L
Four-Wheel Drive Low Range — This range locks the front
and rear driveshafts together forcing the front and rear
wheels to rotate at the same speed. Additional traction and
maximum pulling power for loose, slippery road surfaces
only. Do not exceed 25 mph (40 km/h).
342 STARTING AND OPERATING
This transfer case is intended to be driven in the 2H
position for normal street and highway conditions such as
dry, hard surfaced roads.
When additional traction is required, the 4H and 4L
positions can be used to lock the front and rear driveshafts
together and force the front and rear wheels to rotate at the
same speed. This is accomplished by simply moving the
gear selector to the desired positions once the appropriate
speed and gear requirements are met, refer to “Shifting
Procedure – Manually Shifted Transfer Case” in this section
for further information.
The 4H and 4L positions are intended for loose, slippery
road surfaces only. Driving in the 4H and 4L positions on
dry, hard surfaced roads may cause increased tire wear and
damage to the driveline components.
The “Transfer Case Position Indicator Light” in the instru-
ment cluster will alert the driver that the vehicle is in
four-wheel drive and that the front and rear driveshafts are
locked together. This light will illuminate when the transfer
case is shifted into either the 4H or 4L position. There is no
light for the 2H or NEUTRAL positions on some models.When operating your vehicle in 4L, the engine speed is
approximately three times that of the 2H or 4H positions at
a given road speed. Take care not to overspeed 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 will adversely affect shifting and can cause
damage to the drivetrain.
NOTE:
Do not attempt to make a shift while only the front
or rear wheels are spinning, as this can cause damage to
driveline components.
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.
NOTE: Delayed shifts out of four-wheel drive may be
experienced due to uneven tire wear, low or uneven tire
pressures, excessive vehicle loading, or cold temperatures.
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STARTING AND OPERATING 343