2021 RAM CHASSIS CAB instrument cluster

150STARTING AND OPERATING
On trucks with AS66RC or AS69RC
transmission, FIFTH and SIXTH gears may
be inhibited briefly on cold starts below
41°F (5°C), and during very cold temperatures
(-4°F [-20°C] or below), operation may briefly
be limited to third gear only. During this
condition, the ability of the vehicle to accelerate
under heavily loaded conditions may be
reduced. In all cases, 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 remains in THIRD gear regardless
of which forward gear is selected. If an
AS66RC/AS69RC 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 damaging 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
recommend that you visit an authorized dealer
at your earliest possible convenience. An autho -
rized dealer has diagnostic equipment to
assess the condition of your transmission.
If the transmission cannot be reset, authorized
dealer service is required.
Electronic Range Select (ERS) Operation
The 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 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, 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.

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STARTING AND OPERATING151

Electronic Range Select

To exit ERS mode, simply push and hold the ERS
(+) switch until the gear limit display disappears
from the instrument cluster. 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 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 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 accelerations, 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 transmis
-
sion 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.
1 — GEAR + Switch
2 — GEAR – Switch
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.4

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152STARTING AND OPERATING
If the vehicle has not been driven for several
days, the first few seconds of operation after
shifting the transmission 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.
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
maneuvers. TOW/HAUL Switch

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.
AUXILIARY SWITCHES — IF EQUIPPED
There can be up to six auxiliary switches located
in the lower switch bank of the instrument panel
which can be used to power various electronic
devices and Power Take Off (PTO). If equipped,
it will take the place of the sixth auxiliary switch.
Connections to the switches are found under
the hood in the connectors attached to the
auxiliary Power Distribution Center.

You have the ability to configure the functionality of
the auxiliary switches via the instrument cluster
display. All switches can now be configured for
setting the switch type operation to latching or
momentary, power source of either battery or
ignition, and ability to hold last state across key
cycles.

NOTE:
Holding last state conditions are met when
switch type is set to latching and power source
is set to ignition.

For further information on using the auxiliary
switches, please refer to the Ram Body Builders
Guide by accessing
https://www.ramtrucks.com/
ram-commercial/body-builders-guide.html
and
choosing the appropriate links.

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 possibly resulting in
personal injury or death.

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154STARTING AND OPERATING
This electronically shifted transfer case is
designed to be driven in the two-wheel drive
position (2WD) for normal street and highway
conditions on dry hard surfaced roads. Driving
the vehicle in two-wheel drive will have greater
fuel economy benefits as the front axle is not
engaged in two-wheel drive.
When additional traction is required, the
transfer case 4WD High and 4WD Low positions
can be used to maximize torque to the front
driveshaft, forcing the front and rear wheels to
rotate at the same speed. This is accomplished
by pushing the desired position on the
four-wheel drive control switch.
For specific shifting instructions Ú page 159.
The 4WD High and 4WD Low positions are
designed for loose, slippery road surfaces only.
Driving in the 4WD High and 4WD Low positions
on dry, hard surfaced roads may cause increased
tire wear and damage to the driveline
components.

NOTE:

The transfer case Neutral button is located in the
center of the four-wheel drive Control Switch and
is pushed by using a ballpoint pen or similar
object. The transfer case Neutral position is to be
used for recreational towing only

Ú
page 214.

Transfer Case Position Indicator Lights
The Transfer Case Position Indicator Lights
(4WD High and 4WD Low) are located in the
instrument cluster and indicate the current and
desired transfer case selection. When you
select a different transfer case position, the
indicator lights will do the following:
If All Of The Following Shift Conditions Are Met:

1. The current position indicator light will turn off.

2. The selected position indicator light will flash until the transfer case completes the
shift. 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 necessary requirements for selecting a new
transfer case position have been met. To retry
the selection, push the current position, wait
five seconds, and retry selection Ú page 159.
The “SVC 4WD Warning Light” monitors the
electronically shifted 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.

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 transmission 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.

WARNING! (Continued)

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158STARTING AND OPERATING
Transfer Case Position Indicator Lights
The Transfer Case Position Indicator Lights
(four-wheel drive and 4WD Low) are located in
the instrument cluster and indicate the current
and desired transfer case selection. When you
select a different transfer case position, the
indicator lights will do the following:
If All Of The Following Shift Conditions Are Met:

1. The current position indicator light will turn off.

2. The selected position indicator light will flash until the transfer case completes the
shift.
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 necessary requirements for selecting a new
transfer case position have been met. To retry
the selection, turn the control switch back to the
current position, wait five seconds, and retry
selection Ú
page 159.
The “SVC 4WD Warning Light” monitors the
electronically shifted 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, as this can
cause damage to driveline components.

When operating your vehicle in 4WD Low, the
engine speed is approximately three times that of
the two-wheel drive or 4WD High 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 in
tire size can cause damage to the drivetrain.
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.

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STARTING AND OPERATING161
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 instrument 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 N (Neutral) positions on
some models.
When operating your vehicle in 4L, the engine
speed is approximately three times that of the
4H or 4L 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.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.
2WD High Or 4WD High To 4WD Low
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.
WARNING!

You or others could be injured or killed if you
leave the vehicle unattended with the transfer
case in the N (NEUTRAL) position without first
fully engaging the parking brake. The transfer
case N (NEUTRAL) position disengages both the
front and rear drive shafts from the powertrain
and will allow the vehicle to roll, even if the
transmission is in PARK. The parking brake
should always be applied when the driver is
not in the vehicle.

4

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162STARTING AND OPERATING
NOTE:
Pausing in transfer case N (Neutral) in vehi -
cles equipped with an automatic transmis -
sion 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 transmission is in gear.
Transfer Case Position Indicator Light
The “Transfer Case Position Indicator Light” in
the instrument cluster is used to alert the driver
that the front axle is fully engaged and all four
wheels are driving.
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 similarly 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 slippery 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
application 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
sideways on the crowned surface of a road or in
a turn.
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.

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STARTING AND OPERATING163
POWER TAKE OFF (PTO) OPERATION — IF
EQUIPPED

This vehicle when equipped with PTO Prep and
the AS66RC/AS69RC 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”, “mobile” or “remote” mode.
The vehicles will be factory set to the “stationary”
mode. To select a different mode, or to change
any other PTO setting, you will need to enter the
commercial vehicle menu on the instrument
cluster screen. Details of the PTO selection
modes and further PTO information is available
at the Ram Truck Bodybuilders web site:
https://
www.ramtrucks.com/ram-commercial/
body-builders-guide.html
POWER STEERING
HYDRAULIC POWER STEERING
The standard power steering system will give
you good vehicle response and increased ease
of maneuverability in tight spaces. The system
will provide mechanical steering capability if
power assist is lost.

If for some reason the power assist is interrupted,
it will still be possible to steer your vehicle. Under
these conditions, you will observe a substantial
increase in steering effort, especially at very low
vehicle speeds and during parking maneuvers.

NOTE:
Increased noise levels at the end of the
steering wheel travel are considered normal
and do not indicate that there is a problem
with the power steering system.
Upon initial start-up in cold weather, the
power steering pump may make noise for a
short amount of time. This is due to the cold,
thick fluid in the steering system. This noise
should be considered normal, and it does not
in any way damage the steering system.
Power Steering Fluid Check
Checking the power steering fluid level at a
defined service interval is not required. The fluid
should only be checked if a leak is suspected,
abnormal noises are apparent, and/or the
system is not functioning as anticipated. Check
fluid level when the engine is cold and off.
Coordinate inspection efforts through an
authorized dealer.
CAUTION!
Prolonged operation of the steering system
at the end of the steering wheel travel will
increase the steering fluid temperature and it
should be avoided when possible. Damage to
the power steering pump may occur.
WARNING!
Fluid level should be checked on a level
surface and with the engine off to prevent
injury from moving parts and to ensure
accurate fluid level reading. Do not overfill.
Use only manufacturer's recommended
power steering fluid.
4

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