2023 RAM CHASSIS CAB service

STARTING AND OPERATING137
If the transmission temperature exceeds normal
operating limits, the powertrain controller will
modify the transmission 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.
NOTE:Use caution when operating a heavily loaded
vehicle at low speeds (such as towing a trailer up a
steep grade, or in stop-and-go traffic) during hot
weather. In these conditions, torque converter slip
can impose a significant additional heat load on
the cooling system. Downshifting the transmission
to the lowest possible gear (when climbing a
grade), or shifting to NEUTRAL (when stopped in
heavy traffic) can help to reduce this excess heat
generation.
During cold temperatures, transmission operation
may be modified depending on engine and
transmission temperature as well as vehicle
speed. This feature improves warm-up time of the
engine and transmission to achieve maximum
efficiency. Engagement of the torque converter
clutch is inhibited until the transmission fluid is
warm Ú page 139. 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
Transmission 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. Transmission 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 authorized
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.
4

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STARTING AND OPERATING141
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 144.
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 N (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 N (Neutral) position is to
be used for recreational towing only Ú page 194.Transfer Case Position Indicator Lights
The Transfer Case Position Indicator Lights (4WD
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 144.
The SERV 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. This could 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.
WARNING!
Always engage the parking brake when powering
down the vehicle if the SERV 4WD Warning Light
is illuminated. Not engaging the parking brake
may allow the vehicle to roll which may cause
personal injury or death.4

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144STARTING AND OPERATING
NOTE:The transfer case N (Neutral) button is located on
the lower left hand corner of the four-wheel drive
Control Switch. The transfer case N (Neutral)
position is to be used for recreational towing only
Úpage 194.
Transfer Case Position Indicator Lights
The Transfer Case Position Indicator Lights (4WD
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 144.
The SERV 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.
Shifting Procedure
NOTE:
If any of the requirements to select a new
transfer case position have not been met, the
transfer case will not shift. The position indi
-
cator light for the previous position will remain
ON and the newly selected position indicator
light will continue to flash until all the require -
ments for the selected position have been met.
To retry a shift: return the control switch back to
the original position, make certain all shift
requirements have been met, wait five seconds
and try the shift again.WARNING!
Always engage the parking brake when powering
down the vehicle if the SERV 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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148STARTING AND OPERATING
HYDRAULIC POWER STEERING
The standard power steering system provides
increased vehicle response and 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. If necessary, add fluid to restore to the proper
indicated level. With a clean cloth, wipe any spilled
fluid from all surfaces Ú
page 421.
CRUISE CONTROL SYSTEMS — IF EQUIPPED
Your vehicle may be equipped with the Cruise
Control system, or the Adaptive Cruise Control
(ACC) system:
Cruise Control will keep your vehicle at a
constant preset speed.
Adaptive Cruise Control (ACC) will adjust the
vehicle speed up to the preset speed to main -
tain a distance with the vehicle ahead.
NOTE:
In vehicles equipped with ACC, if ACC is not
enabled, Fixed Speed Cruise Control will not
detect vehicles directly ahead of you. Always be
aware of the feature selected.
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.
CAUTION!
Do not use chemical flushes in your power
steering system as the chemicals can damage
your power steering components. Such damage
is not covered by the New Vehicle Limited
Warranty.

23_DPF_OM_EN_USC_t.book Page 148

STARTING AND OPERATING157
This message can sometimes be displayed while
driving in adverse weather conditions. The ACC/
FCW system will recover after the vehicle has left
these areas. Under rare conditions, when the
camera is not tracking any vehicles or objects in its
path this warning may temporarily occur.
If weather conditions are not a factor, the driver
should examine the windshield and the camera
located on the back side of the inside rearview
mirror. They may require cleaning or removal of an
obstruction.
When the condition that created limited
functionality is no longer present, the system will
return to full functionality.
NOTE:If the “ACC/FCW Limited Functionality Clean Front
Windshield” message occurs frequently (e.g. more
than once on every trip) without any snow, rain,
mud, or other obstruction, have the windshield and
forward facing camera inspected at an authorized
dealer.
SERVICE ACC/FCW WARNING
If the system turns off, and the instrument cluster
displays “ACC/FCW Unavailable Service Required”
or “Cruise/FCW Unavailable Service Required”,
there may be an internal system fault or a
temporary malfunction that limits ACC
functionality. Although the vehicle is still drivable
under normal conditions, ACC will be temporarily unavailable. If this occurs, try activating ACC again
later, following an ignition cycle. If the problem
persists, see an authorized dealer.
Precautions While Driving With ACC
NOTE:
Aftermarket add-ons such as snowplows, lift
kits, and brush/grille bars can hinder module
performance. Ensure the radar/camera has no
obstructions in the field of view.
Height modifications can limit module perfor
-
mance and functionality.
Do not put stickers or easy passes over the
camera/radar field of view.
Any modifications to the vehicle that may
obstruct the field of view of the radar/camera
are not recommended.
In certain driving situations, ACC may have
detection issues. In these cases, ACC may brake
late or unexpectedly. The driver needs to stay alert
and may need to intervene. The following are
examples of these types of situations:
TOWING A TRAILER
ACC while towing a trailer is recommended only
with an Integrated Trailer Brake Controller.
Aftermarket trailer brake controllers will not
activate the trailer brakes when ACC is braking.
OFFSET DRIVING
ACC may not detect a vehicle in the same lane that
is offset from your direct line of travel, or a vehicle
merging in from a side lane. There may not be
sufficient distance to the vehicle ahead. The offset
vehicle may move in and out of the line of travel,
which can cause your vehicle to brake or
accelerate unexpectedly.

Offset Driving Condition Example

TURNS AND BENDS
When driving on a curve with ACC engaged, the
system may decrease the vehicle speed and
acceleration for stability reasons, with no target
vehicle detected. Once the vehicle is out of the
curve the system will resume your original set
speed. This is a part of normal ACC system
functionality.
4

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162STARTING AND OPERATING
NOTE:ParkSense will reduce the volume of the radio, if
on, when the system is sounding an audio tone.
ParkSense Camera Activation
If the ParkSense system detects an obstacle, a
camera image will display in the radio. The camera
will continue to display as long as the ParkSense
system continues to detect an object. This can be
turned on or off in the Uconnect system
Úpage 199.
Front Park Assist Audible Alerts
ParkSense will turn off the Front Park Assist
audible alert (chime) after approximately three
seconds when an obstacle has been detected, the
vehicle is stationary, and brake pedal is applied.
Adjustable Chime Volume Settings
The Front and Rear chime volume settings are
programmable through the Uconnect system
Ú page 199.
ENABLING AND DISABLING PARKSENSE
Front ParkSense can be enabled and
disabled with the Front ParkSense
switch.
Rear ParkSense can be enabled and disabled with
the Rear ParkSense switch.
When the gear selector is moved to REVERSE and
the Front or Rear system is disabled, the instrument cluster display will show a vehicle
graphic with an “Off” message overlay over the
system that is off (Front or Rear system). This
vehicle graphic will be displayed for as long as the
vehicle is in REVERSE.
The Front or Rear ParkSense switch LED will be on
when Front or Rear ParkSense is disabled or
requires service. The Front or Rear ParkSense
switch LED will be off when the Front or Rear
system is enabled. If the Front or Rear ParkSense
switch is pushed, and the system requires service,
the Front or Rear ParkSense switch LED will blink
momentarily, and then the LED will be on.
SERVICE THE PARKSENSE PARK ASSIST
S
YSTEM
During vehicle start-up, when the Front/Rear
ParkSense System has detected a faulted
condition, the instrument cluster display will show
the "Front/Rear ParkSense Unavailable Service
Required" or the "Front/Rear ParkSense
Unavailable Wipe Sensors" message.
When the gear selector is moved into REVERSE, a
vehicle graphic will show in the instrument cluster
display, along with the display overlay “Wipe
Sensors.” If the system needs service, the display
overlay will read “Service.” Under this condition,
ParkSense will not operate. If "Front/Rear ParkSense Unavailable Wipe
Sensors" appears in the instrument cluster display
make sure the outer surface and the underside of
the rear fascia/bumper is clean and clear of snow,
ice, mud, dirt or other obstruction, and then cycle
the ignition. If the message continues to appear,
see an authorized dealer.
If "Front/Rear ParkSense Unavailable Service
Required" appears in the instrument cluster
display, see an authorized dealer.
CLEANING THE PARKSENSE SYSTEM
Clean the ParkSense sensors with water, car wash
soap and a soft cloth. Do not use rough or hard
cloths. Do not scratch or poke the sensors.
Otherwise, you could damage the sensors.
PARKSENSE SYSTEM USAGE
P
RECAUTIONS
NOTE:
Ensure that the front and rear bumpers are free
of snow, ice, mud, dirt and debris to keep the
ParkSense system operating properly.
Jackhammers, large trucks, and other vibra -
tions could affect the performance of
ParkSense.

23_DPF_OM_EN_USC_t.book Page 162

STARTING AND OPERATING163
When you move the gear selector to the
REVERSE position and Front or Rear ParkSense
is turned off, the instrument cluster display will
show "Off" on the vehicle graphic arcs. This
vehicle graphic will be displayed for as long as
the vehicle is in REVERSE.
ParkSense, when on, will reduce the volume of
the radio when it is sounding a tone.
Clean the ParkSense sensors regularly, taking
care not to scratch or damage them. The
sensors must not be covered with ice, snow,
slush, mud, dirt or debris. Failure to do so can
result in the system not working properly. The
ParkSense system might not detect an obstacle
behind or in front of the fascia/bumper, or it
could provide a false indication that an obstacle
is behind or in front of the fascia/bumper.
Use the ParkSense switch to turn the ParkSense
system off if obstacles such as bicycle carriers,
trailer hitches, etc. are placed within 18 inches
(45 cm) of the rear fascia/bumper. Failure to do
so can result in the system misinterpreting a
close obstacle as a sensor problem, causing the
“Front/Rear ParkSense Unavailable Service
Required” message to appear in the instrument
cluster display.
LANESENSE — IF EQUIPPED
LANESENSE OPERATION
The LaneSense system is operational at speeds
above 37 mph (60 km/h) and below 112 mph
(180 km/h). It uses a forward looking camera to
detect lane markings and measure vehicle
position within the lane boundaries.
When both lane markings are detected and the
driver drifts out of the lane (no turn signal has been
applied) OR the driver departs the lane on the
opposite side of the applied turn signal (if the left
turn signal is applied and the vehicle departs to the
right), the LaneSense system provides a haptic
WARNING!
Drivers must be careful when backing up even
when using ParkSense. Always check carefully
behind your vehicle, look behind you, and be
sure to check for pedestrians, animals, other
vehicles, obstructions, and blind spots before
backing up. You are responsible for safety and
must continue to pay attention to your
surroundings. Failure to do so can result in
serious injury or death.
Before using ParkSense, it is strongly recom -
mended that the ball mount and hitch ball
assembly be disconnected from the vehicle
when the vehicle is not used for towing.
Failure to do so can result in injury or damage
to vehicles or obstacles because the hitch ball
will be much closer to the obstacle than the
rear fascia when the vehicle sounds the
continuous tone. Also, the sensors could
detect the ball mount and hitch ball assembly,
depending on its size and shape, giving a false
indication that an obstacle is behind the
vehicle.
CAUTION!
ParkSense is only a parking aid and it is
unable to recognize every obstacle, including
small obstacles. Parking curbs might be
temporarily detected or not detected at all.
Obstacles located above or below the sensors
will not be detected when they are in close
proximity.
The vehicle must be driven slowly when using
ParkSense in order to be able to stop in time
when an obstacle is detected. It is recom -
mended that the driver looks over his/her
shoulder when using ParkSense.4

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STARTING AND OPERATING179
NOTE:When working with DEF, it is important to know
that:
Any containers or parts that come into contact
with DEF must be DEF compatible (plastic or
stainless steel). Copper, brass, aluminum, iron
or non-stainless steel should be avoided as they
are subject to corrosion by DEF.
If DEF is spilled, it should be wiped up
completely.
Adding Diesel Exhaust Fluid (DEF)
The DEF gauge (located on the instrument cluster)
will display the level of DEF remaining in the tank
Úpage 89.
NOTE:
Driving conditions (altitude, vehicle speed, load,
etc.) will effect the amount of DEF that is used in
your vehicle.
Another factor is that outside temperature can
affect DEF consumption. In cold conditions,
12°F (-11°C) and below, the DEF gauge needle
can stay on a fixed position and may not move
for extended periods of time. This is a normal
function of the system.
There is an electric heater inside the DEF tank
that automatically works when necessary. If the
DEF supply does freeze, the truck will operate
normally until it thaws.
DEF FILL PROCEDURE
NOTE:
For the correct fluid type Ú page 419.
Remove cap from DEF tank (located on drivers side
of the vehicle or in fuel door).

DEF Filler Cap And Fuel Fill Chassis Cab Models

NOTE:
The DEF gauge may take up to five seconds to
update after adding a gallon or more of DEF to
the DEF tank. If you have a fault related to the
DEF system, the gauge may not update to the
new level. See an authorized dealer for service.
The DEF gauge may also not immediately
update after a refill if the temperature of the
DEF fluid is below 39°F (4°C). The DEF tank
heater will possibly warm up the DEF fluid and
allow the gauge to update after a period of run
time. Under very cold conditions, it is possible
that the gauge may not reflect the new fill level
for several drives.
At 40°F (4°C) you could see some increase in
the DEF gauge due to the tank thawing. The
gauge and level sensor are working properly and
are just updating with proper thawed DEF.
Excessive overfilling of the DEF tank can result
in a MIL lamp/fault code and inaccurate level
readings.
Refilling With Nozzles
You can fill up at any DEF distributor.
Proceed as follows:
Insert the DEF nozzle in the filler tube, start
refilling and stop refilling at the first shut-off (the
shut-off indicates that the DEF tank is full). DO
NOT proceed with the refilling, to prevent
spillage of DEF.
Extract the nozzle.
1 — Diesel Exhaust Fluid (DEF) Fill Location
2 — Diesel Fuel Fill Location
4

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