2021 RAM CHASSIS CAB brake fluid

128STARTING AND OPERATING
STARTING FLUIDS
The engine is equipped with an automatic
electric air preheating system. If the
instructions in this manual are followed,
the engine should start in all conditions.
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.
WARNING!
Starting fluids or flammable liquids must
never be used in the Cummins diesel engine
(see Warning label). Never pour diesel fuel,
flammable liquid, starting fluids (ether) into
the air cleaner canister, air intake piping, or
turbocharger inlet in an attempt to start the
vehicle. This could result in a flash fire and
explosion causing serious personal injury and
engine damage.
WARNING!
Do not leave children or animals inside
parked vehicles in hot weather. Interior
heat build-up may cause serious injury or
death.
When leaving the vehicle, always remove
the key fob and lock your vehicle.

Never leave children alone in a vehicle, or
with access to an unlocked vehicle. Allowing
children 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 mode. A child could
operate power windows, other controls, or
move the vehicle.

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132STARTING AND OPERATING
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. Fuel pump noise may
increase during low speed/light load conditions
when ambient temperature is above 100°F
(38°C), and when fuel tank level is below 10%.
This is a normal condition of the fuel system and
controls strategy. If at any time the check
engine light is on, please visit an authorized
dealer.

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STARTING AND OPERATING149
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.
The engine may be started in this range. 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 150. Under
these conditions, using a lower gear range will
improve performance and extend transmission
life by reducing excessive shifting and heat
buildup.

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 addi
-
tional heat load on the cooling system. Down -
shifting 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 151.
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 350.
For Recreational Towing Ú page 215.
4

21_DPF_OM_EN_USC_t.book Page 149

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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200STARTING AND OPERATING
GROSS AXLE WEIGHT RATING (GAWR)
The GAWR is the maximum permissible load
on the front and rear axles. The load must be
distributed in the cargo area so that the GAWR
of each axle is not exceeded.

Each axle GAWR is determined by the
components in the system with the lowest load
carrying capacity (axle, springs, tires or wheels).
Heavier axles or suspension components
sometimes specified by purchasers for increased
durability does not necessarily increase the
vehicle's GVWR.

TIRE SIZE
The tire size on the Vehicle Certification Label
represents the actual tire size on your vehicle.
Replacement tires must be equal to the load
capacity of this tire size.
RIM SIZE
This is the rim size that is appropriate for the tire
size listed.
INFLATION PRESSURE

This is the cold tire inflation pressure for your
vehicle for all loading conditions up to full GAWR.

CURB WEIGHT

The curb weight of a vehicle is defined as the
total weight of the vehicle with all fluids, including
vehicle fuel, at full capacity conditions, and with
no occupants or cargo loaded into the vehicle.
The front and rear curb weight values are
determined by weighing your vehicle on a
commercial scale before any occupants or
cargo are added.

LOADING
The actual total weight and the weight of the
front and rear of your vehicle at the ground can
best be determined by weighing it when it is
loaded and ready for operation.
The entire vehicle should first be weighed on a
commercial scale to ensure that the GVWR has
not been exceeded. The weight on the front and
rear of the vehicle should then be determined
separately to be sure that the load is properly
distributed over the front and rear axles.
Weighing the vehicle may show that the GAWR
of either the front or rear axle has been
exceeded but the total load is within the
specified GVWR. If so, weight must be shifted
from front to rear or rear to front as appropriate
until the specified weight limitations are met. Store the heavier items down low and be sure
that the weight is distributed equally. Stow all
loose items securely before driving.
Improper weight distributions can have an
adverse effect on the way your vehicle steers
and handles and the way the brakes operate.
TRAILER TOWING
In this section you will find safety tips and
information on limits to the type of towing you
can reasonably do with your vehicle. Before
towing a trailer, carefully review this information
to tow your load as efficiently and safely as
possible.
To maintain the New Vehicle Limited Warranty
coverage, follow the requirements and
recommendations in this manual concerning
vehicles used for trailer towing.
CAUTION!

Do not load your vehicle any heavier than the
GVWR or the maximum front and rear GAWR. If
you do, parts on your vehicle can break, or it
can change the way your vehicle handles.
This could cause you to lose control. Also
overloading can shorten the life of your vehicle.

21_DPF_OM_EN_USC_t.book Page 200

STARTING AND OPERATING211
This light check sequence will continue for a
total of five minutes.
The sequence will only activate if the following
conditions are met:
Vehicle is equipped with the Trailer Tow
Package
Vehicle is in PARK
Vehicle is not in motion
Ignition in ACC or RUN
Remote start is inactive
Brakes are not applied
Left turn signal is not applied
Right turn signal not applied
Hazard switch is not applied
The sequence will cancel if any of the following
conditions occur:
Brakes are applied
Vehicle is shifted from PARK
Vehicle is no longer stationary
Left turn signal activated from stalk
Right turn signal is activated from stalk
Hazard switch is activated
Any button on the key fob is pushed
Ignition button is pushed
High Beam stalk position is changed
Sequence is canceled in the instrument
cluster
TOWING TIPS
Before setting out on a trip, practice turning,
stopping, and backing up the trailer in an area
located away from heavy traffic.
Automatic Transmission
The DRIVE range can be selected when towing.
The transmission controls include a drive
strategy to avoid frequent shifting when towing.
However, if frequent shifting does occur while in
DRIVE, select TOW/HAUL mode or select a lower
gear range (using the Electronic Range Select
(ERS) shift control). NOTE:
Using TOW/HAUL mode or selecting a lower
gear range (using the ERS shift control) while
operating the vehicle under heavy loading
conditions will improve performance and
extend transmission life by reducing excessive
shifting and heat build-up. This action will also
provide better engine braking.
Six-Speed Automatic Transmission Only
When towing a loaded trailer up steep grades
at low speeds (20 mph [32 km/h] or below),
holding your vehicle in FIRST gear (using the
ERS shift control) can help to avoid
transmission overheating.
If you regularly tow a trailer for more than
45 minutes of continuous operation, then
change the automatic transmission fluid and
filter(s) as specified for "police, taxi, fleet, or
frequent trailer towing." Ú
page 354.
NOTE:
Check the automatic transmission fluid level
before towing (Six-speed automatic only).
4

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STARTING AND OPERATING215
(Continued)
RECREATIONAL TOWING — TWO-WHEEL
D
RIVE MODELS
DO NOT flat tow this vehicle. Damage to the
drivetrain will result.
Recreational towing (for two-wheel drive
models) is allowed ONLY if the rear wheels are
OFF the ground. This may be accomplished
using a tow dolly or vehicle trailer. If using a tow
dolly, follow this procedure:

1. Properly secure the dolly to the tow vehicle, following the dolly manufacturer's
instructions.

2. Drive the rear wheels onto the tow dolly.
3. Firmly apply the parking brake. Place automatic transmission in PARK.
4. Properly secure the rear wheels to the dolly, following the dolly manufacturer's
instructions.
5. Turn the ignition to the OFF position and remove the key fob.
6. Install a suitable clamping device, designed for towing, to secure the front wheels in the
straight position.
RECREATIONAL TOWING —
F
OUR-WHEEL DRIVE MODELS
NOTE:
Both the manual shift and electronically shifted
transfer cases must be shifted into N (Neutral)
for recreational towing. Automatic transmis -
sions must be shifted into PARK for recreational
towing. Refer to the following for the proper
transfer case N (Neutral) shifting procedure for
your vehicle.
CAUTION!
Towing with the rear wheels on the ground
will cause severe transmission damage.
Damage from improper towing is not
covered under the New Vehicle Limited
Warranty.
Do not disconnect the driveshaft because
fluid may leak from the transmission,
causing damage to internal parts.
CAUTION!
DO NOT dolly tow any four-wheel drive
vehicle. Towing with only one set of wheels
on the ground (front or rear) will cause
severe transmission and/or transfer case
damage. Tow with all four wheels either ON
the ground, or OFF the ground (using a
vehicle trailer).
Tow only in the forward direction. Towing
this vehicle backwards can cause severe
damage to the transfer case.
Before recreational towing, the transfer
case must be in NEUTRAL. To be certain the
transfer case is fully in NEUTRAL, perform
the procedure outlined under “Shifting Into
NEUTRAL”. Internal transmission damage
will result, if the transfer case is not in
NEUTRAL during towing.
The transmission must be placed in PARK
for recreational towing.

Towing this vehicle in violation of the above
requirements can cause severe transmis-
sion and/or transfer case damage. Damage
from improper towing is not covered under
the New Vehicle Limited Warranty.

4

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216STARTING AND OPERATING
Shifting Into N (Neutral)
Use the following procedure to prepare your
vehicle for recreational towing.
1. Bring the vehicle to a complete stop on
level ground, with the engine running.
Firmly apply the parking brake.

2. Shift the transmission to NEUTRAL.
3. Press and hold the brake pedal.
4. Shift the transfer case into N (Neutral):
With manual shift transfer case, shift the
transfer case lever into N (Neutral).

With electronically shifted transfer
case, push and hold the transfer case
N (Neutral) button. Some models have a
small, recessed "N" button (at the center
of the transfer case switches) that must be
pressed using a ballpoint pen or similar
object. Other models have a rectangular
N (Neutral) switch, below the rotary
transfer case control knob. The N (Neutral)
indicator light will blink while the shift is in progress. The light will stop blinking (stay
on solid) when the shift to N (Neutral) is
complete. After the shift is completed and
the N (Neutral) light stays on, release the
N (Neutral) button.

5. Release the parking brake.
6. Shift the transmission into REVERSE.
7. Release the brake pedal for five seconds and ensure that there is no vehicle
movement.
8. Repeat steps 6 and 7 with automatic transmission in DRIVE.
9. Shift the transmission to NEUTRAL. Firmly apply the parking brake. Turn off the engine.
For vehicles with Keyless Enter-N-Go, push
and hold the ENGINE START/STOP button
until the engine shuts off.
10. Shift the transmission into PARK.
11. Place the ignition in the OFF mode, and remove the key fob.
12. Attach the vehicle to the tow vehicle using a suitable tow bar.
13. Release the parking brake.
Do not disconnect the rear driveshaft
because fluid will leak from the transfer
case, causing damage to internal parts.
Do not use a bumper-mounted clamp-on
tow bar on your vehicle. The bumper face
bar will be damaged.
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 driveshafts from the
powertrain, and will allow the vehicle to
roll, even if the automatic transmission is
in PARK (or manual transmission is in gear).
The parking brake should always be applied
when the driver is not in the vehicle.
CAUTION! (Continued)CAUTION!
It is necessary to follow these steps to be
certain that the transfer case is fully in
NEUTRAL (N) before recreational towing to
prevent damage to internal parts.

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