2023 RAM CHASSIS CAB brake

124STARTING AND OPERATING
ENGINE IDLING

Avoid prolonged idling. Long periods of idling may be
harmful to your engine because combustion
chamber temperatures can drop so low that the fuel
may not burn completely. Incomplete combustion
allows carbon and varnish to form on piston rings,
engine valves, and injector nozzles. Also, the
unburned fuel can enter the crankcase, diluting the
oil and causing rapid wear to the engine.

If the engine is allowed to idle or the truck is driven
on low engine speed drive cycles for more than two
hours, the system will automatically enter an
emissions operating mode that will increase the
engine idle speed to 900 RPM (1,050 RPM for
Chassis Cab). While in this mode, which is
designed to help maintain the Diesel Particulate
Filter, the engine idle speed will return to normal
when the brake pedal is applied. A small change in
engine tone or a slight change in engine
performance while accelerating may also be
noticeable at speeds below 20 mph (32 km/h).
This operating mode may last for up to an hour of
idle time, or around 20 minutes of driving time.

Your truck may have been ordered with an optional
voltage monitoring idle up feature. If a load is placed
on the electrical system while the truck is in PARK,
this feature will attempt to maintain normal system
voltage by automatically increasing engine idle
speed. You may notice several consecutive increases
in idle speed, up to a maximum of 1,450 RPM, as the system will attempt to utilize the smallest increase in
idle speed necessary to maintain normal system
voltage. The idle speed will return to normal when
either the electrical load is removed, or when the
brake pedal is applied.

NOTE:For instrument cluster display messages related to
the vehicle's exhaust system Ú
page 89.
Idle-Up Feature
The driver-controlled high idle speed feature will
help increase cylinder temperatures and provide
additional cab heat, however, excessive idling may
still cause the exhaust after-treatment system to
not properly regenerate. Extended periods of idle
time should be avoided.
The Idle-Up feature uses the Cruise Control buttons
to increase engine idle speed and quickly warm the
vehicle's interior.

1. With the transmission in PARK, the parking
brake applied, and the engine running, turn
on the Cruise Control, then push the SET (-)
button.

2. The engine RPM will go up to 1,100 RPM. To increase the RPM, push and hold the RES (+)
button and the idle speed will increase to
approximately 1,500 RPM. To decrease the
RPM, push and hold the SET (-) button and the
idle speed will decrease to approximately
1,100 RPM. 3. To cancel the Idle–Up feature, either push the
CANCEL button, push the ON/OFF button, or
press the brake pedal.
NOISE
Diesel engines can create noises that may seem
as a concern. The nature of a diesel engine is
compression ignition where compressed air and
fuel are mixed and ignited. Weather, barometric
pressure, altitude and temperature will affect how
fuel is ignited in the engine. Engines will sound
different from day to day or previous model years.
Clicking, ticking, or light knocking is normal and will
change from day to day, as the engine breaks in,
and can vary with changes in ambient
temperature; this is normal. Diesel equipped
vehicles also have an exhaust after treatment
system to reduce emissions utilizing a Diesel
Particulate Filter (DPF) and a Selective Reduction
Catalyst (SCR). The SCR reduces Nox using the
Diesel Exhaust Fluid (DEF) system. DEF is injected
directly into the SCR through an dosing module.
This process will create a clicking sound and at
times, will make noise even with the vehicle shut
off. This is normal as the DEF dosing module is
purging DEF. If at any time the check engine light is
on, please visit an authorized dealer.

23_DPF_OM_EN_USC_t.book Page 124

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

130STARTING AND OPERATING
(Continued)
(Continued)
NOTE:For optimum braking power it is recommended to
use the exhaust brake while in TOW/HAUL mode.
The exhaust brake feature can also be used to
reduce the engine warm-up time. To use the
exhaust brake as a warm-up device, the vehicle
must be stopped or moving less than 5 mph
(8 km/h), the Exhaust Brake Indicator must be on,
and the coolant temperature must be below
180°F (82°C) and ambient temperature below
60°F (16°C).
Automatic “Smart” Exhaust Brake
Automatic “Smart” Exhaust Brake technology
delivers smoother, less aggressive exhaust
braking characteristics during downhill descents.
Although it can apply full exhaust braking force if
needed, Automatic “Smart” Exhaust Brake may
not apply obvious braking if the vehicle speed is
not increasing. Automatic “Smart” Exhaust Brake
is intended to maintain vehicle speed, while Full
Exhaust Brake is intended to reduce vehicle speed. Automatic “Smart” Exhaust Brake can be enabled
by pushing the exhaust brake button (on the center
stack) again anytime after the normal Full Exhaust
Brake has been turned on. The Exhaust Brake
Indicator in the instrument cluster display will
change from Yellow to Green when Automatic
“Smart” Exhaust Brake is enabled. Pushing the
exhaust brake button again will toggle the exhaust
brake mode to off.
AUTOMATIC TRANSMISSION
You must press and hold the brake pedal while
shifting out of PARK.
CAUTION!
Use of aftermarket exhaust brakes is not
recommended and could lead to engine
damage.
WARNING!
It is dangerous to shift out of PARK or
NEUTRAL if the engine speed is higher than
idle speed. If your foot is not firmly pressing
the brake pedal, the vehicle could accelerate
quickly forward or in reverse. You could lose
control of the vehicle and hit someone or
something. Only shift into gear when the
engine is idling normally and your foot is firmly
pressing the brake pedal.
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 indi
-
cator solidly indicates PARK (P) without
blinking. Ensure that the vehicle is completely
stopped, and the PARK position is properly
indicated, before exiting the vehicle.
Unintended movement of a vehicle could
injure those in or near the vehicle. As with all
vehicles, you should never exit a vehicle while
the engine is running. Before exiting a vehicle,
always come to a complete stop, then apply
the parking brake, shift the transmission into
PARK, turn the engine OFF, and remove the
key fob. When the ignition is in the LOCK/OFF
(key removal) position, (or, with Keyless Enter
‘n Go™, when the ignition is in the OFF posi -
tion) the transmission is locked in PARK,
securing the vehicle against unwanted move -
ment.
When leaving the vehicle, always make sure
the ignition is in the OFF position, remove the
key fob from the vehicle, and lock the vehicle.
WARNING!

23_DPF_OM_EN_USC_t.book Page 130

STARTING AND OPERATING131
IGNITION PARK INTERLOCK
This vehicle is equipped with an Ignition Park
Interlock which requires the transmission to be in
PARK before the ignition can be turned to the OFF
position. This helps the driver avoid inadvertently
leaving the vehicle without placing the
transmission in PARK. This system also locks the
transmission in PARK whenever the ignition is in
the OFF position.
NOTE:The transmission is NOT locked in PARK when the
ignition is in the ACC position (even though the
engine will be off). Ensure that the transmission is
in PARK, and the ignition is OFF (not in ACC
position) before exiting the vehicle.
BRAKE/TRANSMISSION SHIFT
I
NTERLOCK (BTSI) SYSTEM
This vehicle is equipped with a BTSI system that
holds the transmission gear selector in PARK
unless the brakes are applied. For vehicles with
8-speed transmission, to shift the transmission out
of PARK, the engine must be running and the brake
pedal must be pressed. The brake pedal must also
be pressed to shift from NEUTRAL into DRIVE or
REVERSE when the vehicle is stopped or moving at
low speeds. For vehicles with 6-speed
transmission, to shift the transmission out of
PARK, the ignition must be in the ON/RUN position
(engine running or not) and the brake pedal must
be pressed.
The BTSI will timeout if brake pedal is pressed for
three minutes or longer continuously while in park.
It can be reset by releasing the brake for more then
three seconds, then reapplying the brake pedal or
cycling the ignition.Never use the PARK position as a substitute
for the parking brake. Always apply the
parking brake fully when exiting the vehicle to
guard against vehicle movement and possible
injury or damage.
Your vehicle could move and injure you and
others if it is not in PARK. Check by trying to
move the gear selector out of PARK with the
brake pedal released. Make sure the trans -
mission is in PARK before exiting the vehicle.
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 transmis -
sion gear selector.
Do not leave the key fob in or near the vehicle
(or in a location accessible to children), and do
not leave the ignition (in 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!CAUTION!
Shift into or out of PARK or REVERSE only after
the vehicle has come to a complete stop.
Do not shift between PARK, REVERSE,
NEUTRAL, or DRIVE when the engine is above
idle speed.
Before shifting into any gear, make sure your
foot is firmly pressing the brake pedal.
4

23_DPF_OM_EN_USC_t.book Page 131

132STARTING AND OPERATING
8-SPEED AUTOMATIC TRANSMISSION —
I
F EQUIPPED
The transmission is controlled using a rotary
electronic gear selector located on the instrument
panel. The transmission gear range (PRND) is
displayed both above the gear selector and in the
instrument cluster. To select a gear range, simply
rotate the gear selector. You must press the brake
pedal to shift the transmission out of PARK (or
NEUTRAL, when the vehicle is stopped or moving at
low speeds). To shift past multiple gear ranges at
once (such as PARK to DRIVE), simply rotate the
gear selector to the appropriate detent. Select the
DRIVE range for normal driving.
NOTE:In the event of a mismatch between the gear
selector position and the actual transmission gear
(for example, driver selects PARK while driving),
the position indicator will blink continuously until
the selector is returned to the proper position, or
the requested shift can be completed.
The electronically controlled transmission adapts
its shift schedule based on driver inputs, along
with environmental and road conditions. 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 positions. Manual
downshifts can be made using the Electronic
Range Select (ERS) shift control. Pushing the
GEAR “-”/GEAR “+” 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 134. Some models will display
both the selected gear limit, and the actual current
gear, while in ERS mode.

Electronic Transmission Gear Selector

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. As an
added precaution, turn the front wheels toward the
curb on a downhill grade and away from the curb
on an uphill grade.
NOTE:On four-wheel drive vehicles be sure that the
transfer case is in a drive position.
When exiting the vehicle, always:
Apply the parking brake.
Shift the transmission into PARK.
Turn the engine off.
Remove the key fob.

23_DPF_OM_EN_USC_t.book Page 132

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