2020 Ram 3500 coolant temperature

120GETTING TO KNOW YOUR INSTRUMENT PANEL
Coolant Temperature
Oil Temperature
Transmission Temperature
Oil Life
Fuel Filter Life — If Equipped
Lower Left — If Equipped
None
Compass
Outside Temp
Time
Range To Empty
Average MPG
Current MPG
Trip A Distance
Trip B Distance
Trailer Trip
Trailer Brake
Oil Pressure
Coolant Temperature
Oil Temperature
Battery Voltage (Default Setting)
Transmission Temperature
Oil Life
Exhaust Brake — If Equipped
Turbo Boost — If Equipped
Fuel Filter Life — If Equipped
Lower Right — If Equipped
None
Compass
Outside Temp
Time
Range To Empty
Average MPG
Current MPG
Trip A Distance
Trip B Distance
Trailer Trip
Trailer Brake
Oil Pressure (Default Setting)
Coolant Temperature
Oil Temperature
Battery Voltage
Transmission Temperature
Oil Life
Exhaust Brake — If Equipped
Turbo Boost — If Equipped
Fuel Filter Life — If Equipped
Restore Defaults
Cancel (Default Setting)
Restore

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GETTING TO KNOW YOUR INSTRUMENT PANEL127
Engine Power Reduced Up To 2 Min
(Minutes) During Warmup — This message
will display during start up when the ambient
temperature is -25°F (-32°C) and below.
Your vehicle is equipped with an engine
warm up protection feature that may limit
engine performance after cold starting at low
ambient temperatures. The length of time
engine speed is limited is dependent upon
engine coolant temperature. Engine speed
may be briefly limited to 1000 RPM after
starting with coolant temperature below
freezing conditions, and may be limited to
1000 RPM for up to approximately 2 minutes
under more severe cold conditions.
Coolant Low — This telltale will turn on to indi -
cate the vehicle coolant level is low. Refer to
“Dealer Service” in “Servicing And Mainte -
nance” for more information.
Diesel Exhaust Fluid (DEF) Warning
Messages
There are four different messages which are
displayed if the vehicle detects that the DEF
system has been filled with a fluid other than
DEF, has experienced component failures, or
when tampering has been detected. The vehicle
may be limited to a maximum speed of 5 MPH (8 km/H) if the DEF system is not serviced
within less than 200 miles (322 km) of the fault
being detected.
When the DEF system needs to be serviced the
following warnings will display:
DEF Low Refill Soon
— This message will
display when the low level is reached, during
vehicle start up, and with increased
frequency during vehicle operation. It will be
accompanied by a single chime. Approxi -
mately 5 gallons (19 Liters) of DEF is required
to refill the tank when this message is initially
displayed. on pickup applications, and
approximately 7 gallons (26 Liters) are
required on chassis-cab applications.
Speed Limited to 5 MPH in XXX mi Refill DEF
— This message will continuously display if
the “DEF Low Refill Soon” message is
ignored, and the frequency of occurrence of
the chime will increase unless up to 2 gallons
(7.5 Liters) of DEF is added to the tank.
5 MPH Max Speed on Restart, Long Idle or
Refuel Refill DEF — This message will contin -
uously display when the counter reaches
zero, and will be accompanied by a periodic
chime. The vehicle will only be capable of a
maximum speed of 5 MPH upon the first of
the following conditions to occur:
If the vehicle is shutoff and restarted.
If the vehicle is idled for an extended
period of time, approximately one hour or
greater.
If the system detects that the level of fuel
in the tank has increased.
Add a minimum of 2 gallons (7.5 Liters) of
DEF to the tank in order to avoid vehicle oper -
ation at a maximum speed of 5 MPH
(8 km/H).
NOTE:
A minimum of 2 gallons (7.5 Liters) may be
required to restore normal vehicle operation.
Although the vehicle will start normally and can
be placed in gear after this message has been
initially displayed, extreme caution should be
utilized since the vehicle will only be capable of
maneuvering at a maximum speed of 5 MPH
(8 km/H).
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132GETTING TO KNOW YOUR INSTRUMENT PANEL
Hood Open Warning Light
This warning light will illuminate when
the hood is ajar/open and not fully
closed.
NOTE:
If the vehicle is moving, there will also be a
single chime.
Vehicle Security Warning Light — If
Equipped
This light will flash at a fast rate for
approximately 15 seconds when the
vehicle security alarm is arming, and
then will flash slowly until the vehicle
is disarmed.
Engine Coolant Temperature Warning
Light
This warning light warns of an
overheated engine condition. If the
engine coolant temperature is too
high, this indicator will illuminate and
a single chime will sound. If the temperature
reaches the upper limit, a continuous chime will
sound for four minutes or until the engine is
able to cool; whichever comes first. If the light turns on while driving, safely pull over
and stop the vehicle. If the Air Conditioning
(A/C) system is on, turn it off. Also, shift the
transmission into NEUTRAL and idle the vehicle.
If the temperature reading does not return to
normal, turn the engine off immediately and call
for service.
Refer to “If Your Engine Overheats” in “In Case
Of Emergency” for further information.
Battery Charge Warning Light
This warning light will illuminate when
the battery is not charging properly. If
it stays on while the engine is running,
there may be a malfunction with the
charging system. Contact an authorized dealer
as soon as possible.
This indicates a possible problem with the
electrical system or a related component.
Oil Pressure Warning Light
This warning light will illuminate to
indicate low engine oil pressure. If the
light turns on while driving, stop the
vehicle, shut off the engine as soon as
possible, and contact an authorized dealer. A
chime will sound when this light turns on. Do not operate the vehicle until the cause is
corrected. This light does not indicate how
much oil is in the engine. The engine oil level
must be checked under the hood.
Oil Temperature Warning Light
This warning light will illuminate to
indicate the engine oil temperature is
high. If the light turns on while driving,
stop the vehicle and shut off the
engine as soon as possible. Wait for oil
temperature to return to normal levels.
Electronic Throttle Control (ETC) Warning
Light
This warning light will illuminate to
indicate a problem with the Electronic
Throttle Control (ETC) system. If a
problem is detected while the vehicle
is running, the light will either stay on or flash
depending on the nature of the problem. Cycle
the ignition when the vehicle is safely and
completely stopped and the transmission is
placed in the PARK (P) position. The light should
turn off. If the light remains on with the vehicle
running, your vehicle will usually be drivable;
however, see an authorized dealer for service
as soon as possible.

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220STARTING AND OPERATING
5. After engine start-up, check to see that
there is oil pressure.
6. Release the parking brake and drive.
NOTE:
Engine idle speed will automatically increase
to 1,000 RPM and engage the Variable
Geometry Turbocharger at low coolant
temperatures to improve engine warm-up.
The engine will not automatically crank after
the engine “Wait To Start” telltale goes off if
a door or the hood is ajar.

If the engine stalls, or if the ignition switch is
left ON for more than two minutes after the
“Wait To Start” telltale goes out, reset the
intake air heater by turning the ignition switch
to the OFF position for at least 5 seconds and
then back ON. Repeat steps 1 through 7 of
“Keyless Enter-N-Go Starting Procedure –
Engine Manifold Air Temperature Below 66° F
(19° C).”

EXTREME COLD WEATHER
The Cummins® Turbo Diesel engine is
equipped with several features designed to
assist cold weather starting and operation:
The engine block heater is a resistance
heater installed in the water jacket of the
engine just above and behind the oil filter. It
requires a 110–115 Volt AC electrical outlet
with a grounded, three-wire extension cord.
NOTE:
The engine block heater cord is a factory
installed option. If your vehicle is not equipped,
heater cords are available from an authorized
Mopar dealer.
A 12 Volt heater built into the fuel filter hous -
ings aid in preventing fuel gelling. It is
controlled by a built-in thermostat.
A intake air heater system both improves
engine starting and reduces the amount of
white smoke generated by a warming engine.
NORMAL STARTING PROCEDURE —
E
NGINE MANIFOLD AIR TEMPERATURE
A
BOVE 66° F (19° C)
Observe the instrument panel cluster lights
when starting the engine.

1. Always apply the parking brake.

2. Shift into PARK for an automatic
transmission.
3. Place the ignition switch in the ON position and watch the instrument panel cluster
lights.
4. Place the ignition switch in the START position and crank the engine. Do not press
the accelerator during starting.
CAUTION!
If the “Water in Fuel Indicator Light” remains
on, DO NOT START the engine before you
drain the water from the fuel filters to avoid
engine damage. Refer to “Draining Fuel/
Water Separator Filter” in “Servicing And
Maintenance” for further information.

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STARTING AND OPERATING221
5. Check that the oil pressure warning light
has turned off.
6. Release the parking brake.
STARTING PROCEDURE — ENGINE
M
ANIFOLD AIR TEMPERATURE 0°F TO
66°F (–18°C
TO 19°C)
NOTE:
The temperature displayed in the instrument
cluster does not necessarily reflect the engine
manifold air temperature. Refer to “Instrument
Cluster Display” in “Getting To Know Your
Instrument Panel” for further information.
When engine temperatures fall below 66°F
(19°C) the “Wait To Start Light” will remain on
indicating the intake air heater system is active. Follow the steps in the “Normal Starting”
procedure except:

1. The “Wait To Start” telltale will remain on
for a period of time that varies depending
on the engine temperature.

2. While the “Wait To Start” telltale is on, the instrument cluster will additionally display a
gauge or bar whose initial length represents
the full “Wait To Start” time period. Its
length will decrease until it disappears
when the “Wait To Start” time has elapsed.
3. After the “Wait To Start” telltale goes off, place the ignition switch in the START
position. Do not press the accelerator
during starting. 4. After engine start-up, check that the oil
pressure warning light has turned off.
5. Release the parking brake and drive.
NOTE:
Engine idle speed will automatically increase
to 1,000 RPM and engage the Variable
Geometry Turbocharger at low coolant
temperatures to improve engine warm-up.
Automatic equipped vehicles with optional
Keyless Enter-N-Go – If the start button is
pushed once while in park with the ignition
off and driver’s foot on the brake pedal, the
vehicle will automatically crank and start
after the Wait to Start time has elapsed. If it
is desired to abort the start process before it
completes, the driver’s foot should be fully
CAUTION!

Do not crank engine for more than 25 seconds
at a time or starter motor damage may result.
Turn the ignition switch to the OFF position and
wait at least two minutes for the starter to cool
before repeating start procedure.

CAUTION!
If the “Water in Fuel Indicator Light” remains
on, DO NOT START the engine before you
drain the water from the fuel filters to avoid
engine damage. Refer to “Draining Fuel/
Water Separator Filter” in “Servicing And
Maintenance” for further information.
CAUTION!

Do not crank engine for more than 25 seconds
at a time or starter motor damage may result.
Turn the ignition switch to the OFF position and
wait at least two minutes for the starter to cool
before repeating start procedure.

5

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222STARTING AND OPERATING
removed from the brake pedal prior to
pushing the start button again in order for the
ignition to move directly to off.
If the engine stalls, or if the ignition switch is
left ON for more than two minutes after the
“Wait To Start” telltale goes out, reset the
intake air heater by turning the ignition
switch to the OFF position for at least five
seconds and then back ON. Repeat steps 1
through 5 of “Starting Procedure – Engine
Manifold Air Temperature Below 66°F
(19°C).”
STARTING PROCEDURE — ENGINE
M
ANIFOLD AIR TEMPERATURE BELOW
0°F (-18°C)
In extremely cold weather below 0°F (-18°C) it
may be beneficial to cycle the intake air heater
twice before attempting to start the engine. This
can be accomplished by turning the ignition OFF
for at least 5 seconds and then back ON after
the “Wait To Start” telltale has turned off, but
before the engine is started. However,
excessive cycling of the intake air heater will
result in damage to the heater elements or
reduced battery voltage. NOTE:
If multiple pre-heat cycles are used before
starting, additional engine run time may be
required to maintain battery state of charge at a
satisfactory level.

1. If the engine stalls after the initial start, the
ignition must be turned to the OFF position
for at least five seconds and then to the ON
position to recycle the intake air heater.

NOTE:
Excessive white smoke and poor engine perfor -
mance will result if intake air heater are not
recycled.
2. Heat generated by the intake air heater dissipates rapidly in a cold engine. If more
than two minutes pass between the time
the “Wait To Start” telltale turns off and the
engine is started, recycle the intake air
heater by turning the ignition switch to the
OFF position for at least five seconds and
then back ON.

3. If the vehicle is driven and vehicle speed exceeds 19 mph (31 km/h) before the intake
air heater post-heat (after start) cycle is
complete, the intake air heater will shut off. 4. If the engine is cranked for more than
10 seconds, the post-heat cycle will turn off.

NOTE:
Engine idle speed will automatically increase
to 1,000 RPM and engage the Variable
Geometry Turbocharger at low coolant
temperatures to improve engine warm-up.
When a diesel engine is allowed to run out of
fuel or the fuel gels at low temperatures, air
is pulled into the fuel system. If your engine
has run out of fuel, refer to “Dealer Service/
Priming If The Engine Has Run Out Of Fuel” in
“Servicing And Maintenance” for further
information.
If the engine stalls, or if the ignition switch is
left ON for more than two minutes after the
“Wait To Start” telltale goes out, reset the
intake air heater by turning the ignition
switch to the OFF position for at least
5 seconds and then back ON. Repeat steps
1 through 5 of “Starting Procedure – Engine
Manifold Air Temperature Below 66°F
(19°C).”

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STARTING AND OPERATING225
The fuel grade should be clearly marked on
the pump at the fuel station.
The engine requires the use of “Ultra Low
Sulfur Diesel Fuel”. Use of incorrect fuel
could result in engine and exhaust system
damage. Refer to “Fuel Requirements” in
“Technical Specifications” for further infor -
mation.
If climatized or diesel Number 1 ULSD fuel is
not available, and you are operating below
(20°F/-6°C), in sustained arctic conditions,
Mopar Premium Diesel Fuel Treatment (or
equivalent) is recommended to avoid gelling
(see Fuel Operating Range Chart).
Under some circumstances increased engine
noise may be audible in the seconds
following a cold start. This is most likely to
occur when using fuel that isn't blended for
the ambient temperature present. This may
occur on an unseasonably cold day or when a
truck is fueled in a warmer climate and driven
to a colder climate. The noise can typically be
prevented by using Mopar Premium Diesel
Fuel Treatment as recommended (see Fuel
Operating Range Chart).
Engine Oil Usage
Refer to “Dealer Service” in “Servicing And
Maintenance” for the correct engine oil
viscosity.
Winter Front Cover Usage
A Winter front or cold weather cover is to be
used in ambient temperatures below 32°F
(0°C), especially during extended idle
conditions. This cover is equipped with four
flaps for managing total grille opening in varying
ambient temperatures. If a Winter front or cold
weather cover is to be used the flaps should be
left in the full open position to allow air flow to
the charge air cooler and automatic
transmission oil cooler. When ambient
temperatures drop below 0°F (-17°C) the four
flaps need to be closed. A suitable cold weather
cover is available from your Mopar dealer.
Battery Blanket Usage
A battery loses 60% of its cranking power as the
battery temperature decreases to 0°F (-18°C).
For the same decrease in temperature, the
engine requires twice as much power to crank
at the same RPM. The use of 120 VAC powered
battery blankets will greatly increase starting capability at low temperatures. Suitable battery
blankets are available from an authorized
Mopar dealer.
Engine Warm-Up
Avoid full throttle operation when the engine is
cold. When starting a cold engine, bring the
engine up to operating speed slowly to allow the
oil pressure to stabilize as the engine warms up.
NOTE:
High-speed, no-load running of a cold engine
can result in excessive white smoke and poor
engine performance. No-load engine speeds
should be kept under 1,000 RPM during the
warm-up period, especially in cold ambient
temperature conditions.
Your vehicle is equipped with an engine warm
up protection feature that may limit engine
performance after cold starting at low ambient
temperatures. The length of time engine speed
is limited is dependent upon engine coolant
temperature. Engine speed may be briefly
limited to 1000 RPM after starting with coolant
temperature below freezing conditions, and
may be limited to 1000 RPM for up to
approximately 2 minutes under more severe
cold conditions.
5

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226STARTING AND OPERATING
NOTE:

If ambient temperatures are low and the coolant
temperature is below 180°F (82°C), the engine
idle speed will slowly increase to 1,000 RPM after
two minutes of idle, if the following conditions are
met:

Foot is off brake pedal and throttle pedal.
Automatic transmission is in PARK.
Vehicle speed is 0 mph (0 km/h).
Applying the throttle will cancel fast idle.
Operating the exhaust brake at idle will
greatly improve warm up rate and will help
keep the engine close to operating tempera -
ture during extended idle.
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 2 hours, the system will
automatically enter an emissions operating
mode that will increase the engine idle speed to
900 RPM. 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, refer to
“Instrument Cluster Display” in “Getting To
Know Your Instrument Panel” for further infor
-
mation.
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
aftertreatment system to not properly
regenerate. Extended periods of idle time
should be avoided.
The Idle-Up feature uses the Speed Control
switches 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,
push the speed control switch to the ON
position, then push the SET switch.

2. The engine RPM will go up to 1,100 RPM. To increase the RPM, push and hold the
ACCEL/RESUME switch and the idle speed
will increase to approximately 1,500 RPM.
To decrease the RPM, push and hold the

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