2023 RAM CHASSIS CAB engine coolant

STARTING AND OPERATING125
STOPPING THE ENGINE
Idle the engine a few minutes before routine shutdown. After full load operation, idle the engine three to five minutes before shutting it down. This idle period
will allow the lubricating oil and coolant to carry excess heat away from the combustion chamber, bearings, internal components, and turbocharger. This is
especially important for turbocharged, charge air-cooled engines. Refer to the following chart for proper engine shutdown:
IDLE SHUTDOWN
This feature can be enabled so that the truck will automatically shutdown when the truck has been idling for a set period of time when the engine is at operating
temperature. Idle time can be set in 5 minute increments between 5 and 60 minutes. See an authorized dealer to enable this feature.
NOTE:The idle shut down timer is disabled while the Power Take Off (PTO) is active.
Driving Condition Load Turbocharger Temperature Idle Time (min.) Before Engine
Shutdown
Stop and Go EmptyCoolLess than One
Stop and Go Medium -One
Highway Speeds MediumWarmTwo
City Traffic Maximum GCWR -Three
Highway Speeds Maximum GCWR -Four
Uphill Grade Maximum GCWR HotFive
4

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126STARTING AND OPERATING
PROGRAMMABLE MAXIMUM VEHICLE
S
PEED
This feature allows the owner to set a maximum
vehicle speed for the vehicle. The 2500 and 3500
Series maximum vehicle speed can be set
between 40 mph to 87 mph (64 km/h to
140 km/h). The 4500/5500 Series maximum
vehicle speed can be set between 40 mph to
85 mph (64 km/h to 136 km/h). See an
authorized dealer to enable this feature.
NOTE:DO NOT set the maximum vehicle speed to a value
greater than what the vehicle tires are rated for.
OPERATING PRECAUTIONS
Avoid Overheating The Engine
The temperature of the engine coolant (antifreeze:
a mixture of 50% ethylene-glycol and 50% water)
must not exceed the normal range of the
temperature gauge 240°F (116°C) with a 21 psi
(145 kPa) coolant pressure cap.
Usually the engine coolant (antifreeze)
temperature indicated during operation will be to
the left of center in the normal range of the gauge.
Avoid Low Coolant Temperature Operation
Continual operation at low engine coolant
(antifreeze) temperature below the normal range
on the gauge 140°F (60°C) can be harmful to the engine. Low engine coolant (antifreeze)
temperature can cause incomplete combustion
which allows carbon and varnish to form on piston
rings and injector nozzles. Also, the unburned fuel
can enter the crankcase, diluting the lubricating oil
and causing rapid wear to the engine.
COOLING SYSTEM TIPS
To reduce potential for engine and transmission
overheating in high ambient temperature
conditions, take the following actions:
City Driving — When stopped, shift the transmis
-
sion into NEUTRAL and increase engine idle
speed.
Highway Driving — Reduce your speed.
Up Steep Hills — Select a lower transmission
gear.
Air Conditioning — Turn it off temporarily.
Do Not Operate The Engine With Low Oil
Pressure
When the engine is at normal operating
temperature, the minimum oil pressures required
are:
Do Not Operate The Engine With Failed
Parts
All engine failures give some warning before the
parts fail. Be on the alert for changes in
performance, sounds, and visual evidence that the
engine requires service. Some important clues are:
Engine misfiring or vibrating severely.
Sudden loss of power.
Unusual engine noises.
Fuel, oil or coolant leaks.
Sudden change, outside the normal operating
range, in the engine operating temperature.
Excessive smoke.
Oil pressure drop.
Idle 700 to 800 RPM 10 psi (69 kPa)
Full speed and load 30 psi (207 kPa)
CAUTION!
If oil pressure falls to less than normal readings,
shut the engine off immediately. Failure to do so
could result in immediate and severe engine
damage.

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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.

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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!

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138STARTING AND OPERATING
You can switch between DRIVE and ERS mode at
any vehicle speed. When the gear selector is in the
DRIVE position, the transmission will operate
automatically, shifting between all available gears.
Tapping the ERS “-” switch will activate ERS mode,
display the current gear in the instrument cluster,
and set that gear as the top available gear. Once in
ERS mode, tapping “-” or “+” will change the top
available gear.

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 acceler -
ator.
When To Use TOW/HAUL Mode
When driving in hilly areas, towing a trailer, carrying
a heavy load, etc., and frequent transmission
shifting occurs, push the TOW/HAUL switch to
activate TOW/HAUL mode. This will improve
performance and reduce the potential for
transmission overheating or failure due to
excessive shifting. When operating in TOW/HAUL
mode, transmission upshifts are delayed, and the
transmission will automatically downshift (for
engine braking) when the throttle is closed and/or
during steady braking maneuvers.

TOW/HAUL Switch

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.

23_DPF_OM_EN_USC_t.book Page 138

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

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324SAFETY
(Continued)
Lights
Have someone observe the operation of brake
lights and exterior lights while you work the
controls. Check turn signal and high beam
indicator lights on the instrument panel.
Door Latches
Check for proper closing, latching, and locking.
Fluid Leaks
Check area under the vehicle after overnight
parking for fuel, coolant, oil, or other fluid leaks.
Also, if gasoline fumes are detected or if fuel or
brake fluid leaks are suspected, the cause should
be located and corrected immediately.
EXHAUST GAS
The best protection against carbon monoxide entry
into the vehicle body is a properly maintained
engine exhaust system.
Whenever a change is noticed in the sound of the
exhaust system, when exhaust fumes can be
detected inside the vehicle, or when the underside
or rear of the vehicle is damaged, have an
authorized dealer inspect the complete exhaust
system and adjacent body areas for broken,
damaged, deteriorated, or mispositioned parts.
Open seams or loose connections could permit
exhaust fumes to seep into the passenger
compartment. In addition, inspect the exhaust
system each time the vehicle is raised for
lubrication or oil change. Replace as required.
CARBON MONOXIDE WARNINGS
WARNING!
Exhaust gases can injure or kill. They contain
carbon monoxide (CO), which is colorless and
odorless. Breathing it can make you
unconscious and can eventually poison you. To
avoid breathing (CO), follow these safety tips:
Do not run the engine in a closed garage or in
confined areas any longer than needed to
move your vehicle in or out of the area.
If you are required to drive with the trunk/lift -
gate/rear doors open, make sure that all
windows are closed and the climate control
BLOWER switch is set at high speed. DO NOT
use the recirculation mode.
If it is necessary to sit in a parked vehicle with
the engine running, adjust your heating or
cooling controls to force outside air into the
vehicle. Set the blower at high speed.
WARNING!
WARNING!
Carbon monoxide (CO) in exhaust gases is
deadly. Follow the precautions below to prevent
carbon monoxide poisoning:
Do not inhale exhaust gases. They contain
carbon monoxide, a colorless and odorless
gas, which can kill. Never run the engine in a
closed area, such as a garage, and never sit in
a parked vehicle with the engine running for
an extended period. If the vehicle is stopped in
an open area with the engine running for more
than a short period, adjust the ventilation
system to force fresh, outside air into the
vehicle.
Guard against carbon monoxide with proper
maintenance. Have the exhaust system
inspected every time the vehicle is raised.
Have any abnormal conditions repaired
promptly. Until repaired, drive with all side
windows fully open.

23_DPF_OM_EN_USC_t.book Page 324

IN CASE OF EMERGENCY335
5. Start the engine in the vehicle that has the booster battery, let the engine idle a few
minutes, and then start the engine in the
vehicle with the discharged battery.
6. Once the engine is started, follow the discon -
necting procedure.
Disconnecting The Jumper Cables

1. Disconnect the negative
(-)
end of the jumper
cable from the engine ground of the vehicle
with the discharged battery.

2. Disconnect the opposite end of the negative (-)
jumper cable from the negative (-) post of the
booster battery.
3. Disconnect the positive (+) end of the jumper
cable from the positive (+) post of the booster
battery.
4. Disconnect the opposite end of the positive (+)
jumper cable from the positive (+) post of the
vehicle with the discharged battery, and
reinstall the protective cap over the positive
(+) post. If frequent jump starting is required to start your
vehicle you should have the battery and charging
system inspected at an authorized dealer.
IF YOUR ENGINE OVERHEATS
If the vehicle is overheating, it will need to be
serviced by an authorized dealer.
Potential signs of vehicle overheating:
Temperature gauge is at HOT (H)
Strong smell of coolant
White smoke coming from engine or exhaust
Coolant bottle coolant has bubbles present
In the event it is observed that the temperature
gauge is moving towards or close to the HOT (H)
position, you can reduce the potential for
overheating by taking the appropriate action.
On the highways — slow down.
In city traffic — while stopped, place the trans
-
mission in NEUTRAL (N), but do not increase the
engine idle speed while preventing vehicle
motion with the brakes.
If your Air Conditioner (A/C) is on, turn it off. The
A/C system adds heat to the engine cooling
system and turning the A/C off can help remove
this heat.
You can also turn the temperature control to
maximum heat, the mode control to floor and
the blower control to high. This allows the heater
core to act as a supplement to the radiator and
aids in removing heat from the engine cooling
system.
CAUTION!
Do not connect jumper cable to any of the fuses
on the positive battery terminal. The resulting
electrical current will blow the fuse.
CAUTION!
Accessories plugged into the vehicle power
outlets draw power from the vehicle’s battery,
even when not in use (i.e., cellular devices, etc.).
Eventually, if plugged in long enough without
engine operation, the vehicle’s battery will
discharge sufficiently to degrade battery life
and/or prevent the engine from starting.
WARNING!
You or others can be badly burned by hot engine
coolant (antifreeze) or steam from your radiator.
If you see or hear steam coming from under the
hood, do not open the hood until the radiator
has had time to cool. Never try to open a cooling
system pressure cap when the radiator or
coolant bottle is hot.
7

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