2023 RAM CHASSIS CAB warning light

122STARTING AND OPERATING
NORMAL OPERATION — DIESEL ENGINE
Observe the following when the engine is
operating.
All message center lights are off.
Malfunction Indicator Light (MIL) is off.
Engine oil pressure is above 10 psi (69 kPa) at
idle.
Voltmeter operation: The voltmeter may show a gauge fluctuation at
various engine temperatures. This cycling
operation is caused by the post-heat cycle of the
intake manifold heater system. The number of
cycles and the length of the cycling operation is
controlled by the engine control module. Post-heat
operation can run for several minutes, and then
the electrical system and voltmeter needle will
stabilize.
The cycling action will cause temporary dimming of
the headlamps, interior lamps, and also a
noticeable reduction in blower motor speed.
COLD WEATHER PRECAUTIONS
Operation in ambient temperature below 32°F
(0°C) may require special considerations. The
following charts suggest these options:
Fuel Operating Range
NOTE:Use Ultra Low Sulfur Diesel (ULSD) Fuels
ONLY.
Fuel Operating Range Chart

*Number 1 ULSD Fuel should only be used where
extended arctic conditions (0°F/-18°C) exist.
NOTE:
Use of Climatized ULSD or Number 1 ULSD Fuel
results in a noticeable decrease in fuel
economy.
Climatized ULSD Fuel is a blend of Number 2
ULSD and Number 1 ULSD Fuels which reduces
the temperature at which wax crystals form in
fuel.
Never leave children alone in a vehicle, or with
access to an unlocked vehicle. Allowing chil -
dren to be in a vehicle unattended is
dangerous for a number of reasons. A child or
others could be seriously or fatally injured.
Children should be warned not to touch the
parking brake, brake pedal or the gear
selector. Do not leave the key fob in or near
the vehicle (or in a location accessible to chil -
dren), and do not leave the ignition of a
vehicle equipped with Keyless Enter ‘n Go™ in
the ACC or ON/RUN position. A child could
operate power windows, other controls, or
move the vehicle.
WARNING!

23_DPF_OM_EN_USC_t.book Page 122

128STARTING AND OPERATING
ENGINE BREAK-IN RECOMMENDATIONS —
DIESEL ENGINE
The Cummins® Turbo Diesel engine does not
require a break-in period due to its construction.
Normal operation is allowed, providing the
following recommendations are followed:
Warm up the engine before placing it under
load.
Do not operate the engine at idle for prolonged
periods.
Use the appropriate transmission gear to
prevent engine lugging.
Observe vehicle oil pressure and temperature
indicators.
Check the coolant and oil levels frequently.
Vary throttle position at highway speeds when
carrying or towing significant weight.
NOTE:Light duty operation such as light trailer towing or
no load operation will extend the time before the
engine is at full efficiency. Reduced fuel economy
and power may be seen at this time.
For additional vehicle break-in requirements
Úpage 186. Because of the construction of the Cummins®
Turbo Diesel engine, engine run-in is enhanced by
loaded operating conditions which allow the
engine parts to achieve final finish and fit during
the first 6,000 miles (10,000 km).
PARKING BRAKE
Before leaving the vehicle, make sure that the
parking brake is fully applied. Also, be certain to
leave the transmission in PARK.
The foot operated parking brake is located below
the lower left corner of the instrument panel. To
apply the parking brake, firmly push the parking
brake pedal fully. To release the parking brake, pull
the parking brake release handle.

Parking Brake Release
When the parking brake is applied with the ignition
switch ON, the Brake Warning Light in the
instrument cluster will illuminate.
NOTE:
When the parking brake is applied and the
transmission is placed in gear, the Brake
Warning Light will flash. If vehicle speed is
detected, a chime will sound to alert the driver.
Fully release the parking brake before
attempting to move the vehicle.
This light only shows that the parking brake is
applied. It does not show the degree of brake
application.
When parking on a hill, it is important to turn the
front wheels toward the curb on a downhill grade
and away from the curb on an uphill grade. Apply
the parking brake before placing the gear selector
in PARK, otherwise the load on the transmission
locking mechanism may make it difficult to move
the gear selector out of PARK. The parking brake
should always be applied whenever the driver is
not in the vehicle.

23_DPF_OM_EN_USC_t.book Page 128

STARTING AND OPERATING129
DIESEL EXHAUST BRAKE (ENGINE
BRAKING)
The purpose of the exhaust brake (engine braking)
feature is to supply negative (braking) torque from
the engine. Typically, the engine braking is used
for, but not limited to, vehicle towing applications
where vehicle braking can be achieved by the
internal engine power, thereby sparing the
mechanical brakes of the vehicle.
Benefits of the exhaust brake are:
Vehicle driving control.
Reduced brake fade.
Longer brake life.
Faster cab warm-up.
The exhaust brake feature will only function when
the driver toggles it on by pushing the exhaust
brake button until the Exhaust Brake Indicator is
illuminated. Normal (Full Strength) exhaust brake
mode is indicated by a yellow Exhaust Brake
Indicator.
Exhaust Brake Switch

Once the Exhaust Brake Indicator is illuminated
and the vehicle is moving faster than 5 mph
(8 km/h); the exhaust brake will automatically
operate when the driver removes pressure from
the accelerator pedal. Exhaust braking is most
effective when the engine RPM is higher. The
automatic transmission will downshift more
aggressively in TOW/HAUL mode when the exhaust
brake is enabled to increase brake performance.
WARNING!
Never use the PARK position as a substitute
for the parking brake. Always apply the
parking brake fully when parked to guard
against vehicle movement and possible injury
or damage.
Never leave children alone in a vehicle, or with
access to an unlocked vehicle. Leaving unat -
tended children in a vehicle is dangerous for a
number of reasons. A child or others could be
seriously or fatally injured.
Do not leave the key fob in or near the vehicle,
or in a location accessible to children, and do
not leave a vehicle equipped with Keyless
Enter ‘n Go™ in the ACC or ON/RUN position.
A child could operate power windows, other
controls, or move the vehicle.
Be sure the parking brake is fully disengaged
before driving; failure to do so can lead to
brake failure and a collision.
Always fully apply the parking brake when
leaving your vehicle or it may roll and cause
damage or injury. Also, be certain to leave the
transmission in PARK. Failure to do so may
cause the vehicle to roll and cause damage or
injury.
CAUTION!
If the Brake System Warning Light remains on
with the parking brake released, a brake system
malfunction is indicated. Have the brake system
serviced by an authorized dealer immediately.
WARNING!
Do not use the exhaust brake feature when
driving in icy or slippery conditions as 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.
4

23_DPF_OM_EN_USC_t.book Page 129

STARTING AND OPERATING133
The following indicators should be used to ensure
that you have properly engaged the transmission
into the PARK position:
Look at the transmission gear position display
and verify that it indicates the PARK position (P),
and is not blinking.
With the brake pedal released, verify that the
gear selector will not move out of PARK.
REVERSE (R)
This range is for moving the vehicle backward.
Shift into REVERSE only after the vehicle has come
to a complete stop.
NEUTRAL (N)
Use this range when the vehicle is standing for
prolonged periods with the engine running. Apply
the parking brake and shift the transmission 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 all
forward gears.
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 to select a lower gear
range
Úpage 134. Under these conditions, using
a lower gear range will improve performance and extend transmission life by reducing excessive
shifting and heat build-up.
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
CAUTION!
DO NOT race the engine when shifting from
PARK or NEUTRAL into another gear range, as
this can damage the drivetrain.
Before moving the transmission gear selector
out of PARK, you must start the engine, and
also press the brake pedal. Otherwise,
damage to the gear selector could result.
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.
For Towing A Disabled Vehicle Ú
page 339.
For Recreational Towing Ú page 195.4

23_DPF_OM_EN_USC_t.book Page 133

STARTING AND OPERATING135
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.
6-SPEED AUTOMATIC TRANSMISSION —
I
F EQUIPPED
Chassis Cab models may use either the AS66RC or
AS69RC transmission (which are equipped with a
Power Take Off (PTO) access cover on the side of
the transmission case).
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 Ú
page 131. 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-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 shift positions.
Manual downshifts can be made using the
Electronic Range Select (ERS) shift control.
Pushing the ERS (“-”/”+”) 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. Úpage 137. Some models will display
both the selected gear limit, and the actual current
gear, while in ERS mode.
Gear Ranges
Do not press the accelerator pedal when shifting
from PARK or NEUTRAL into another gear range.
NOTE:After selecting any gear range, wait a moment to
allow the selected gear to engage before acceler -
ating. This is especially important when the engine
is cold.
PARK (P)
This range supplements the parking brake by
locking the transmission. The engine can be
started in this range. Never attempt to use PARK
while the vehicle is in motion. Apply the parking
brake when exiting the vehicle in this range.
When parking on a hill, apply the parking brake
before shifting the transmission to PARK,
otherwise the load on the transmission locking
mechanism may make it difficult to move the gear
selector out of PARK. As an added precaution, turn
the front wheels toward the curb on a downhill
grade and away from the curb on an uphill grade.
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.4

23_DPF_OM_EN_USC_t.book Page 135

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

23_DPF_OM_EN_USC_t.book Page 137

STARTING AND OPERATING139
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.
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 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 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.
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 Builder’s
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.4

23_DPF_OM_EN_USC_t.book Page 139

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

23_DPF_OM_EN_USC_t.book Page 141