2020 Ram 3500 Chassis Cab coolant

198STARTING 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 aftertreat -
ment 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,
turn on the speed control, 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
DECEL switch and the idle speed will
decrease to approximately 1,100 RPM.
3. To cancel the Idle–Up feature, either push the CANCEL switch, push the ON/OFF
switch, 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. Engine’s 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 aftertreatment 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.
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 espe
-
cially important for turbocharged, charge
air-cooled engines. Refer to the following chart
for proper engine shutdown:

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200STARTING AND OPERATING
Operating Precautions
Avoid Overheating The Engine
The temperature of the engine coolant (anti -
freeze: 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 (anti -
freeze) 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 condi -
tions, take the following actions:
City Driving — When stopped, shift the trans -
mission 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 perfor -
mance, 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 oper -
ating range, in the engine operating tempera -
ture.
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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STARTING AND OPERATING201
Diesel Particulate Filter (DPF) Manual
Regeneration - If Equipped
On equipped chassis cabs, a manual regenera -
tion can be enable through the instrument
cluster. The manual regeneration will allow the
DPF to complete a regeneration, lowering the
soot level without having to drive the vehicle.
The vehicle must be in park to access this
feature, and the fuel level must be over 12.5%
full. A message displaying the time left on the
regeneration will appear on the instrument
cluster, and the instrument cluster will display
the soot level. Refer to “Instrument Cluster
Display” in “Getting to Know Your Instrument
Panel” for further information.
ENGINE BLOCK HEATER — IF EQUIPPED
The engine block heater warms the engine, and
permits quicker starts in cold weather. Connect
the cord to a standard 110-115 Volt AC elec -
trical outlet with a grounded, three-wire exten -
sion cord.
Gas Engine Only
The engine block heater cord is routed through
the grille by the right front tow hook. It includes a removable cap that is secured by a
tethered strap. It also has a c-clip that is used
for storage when not in use for the Winter
months. During Winter months, remove the
heater cord wiring assembly from itself on the
c-clip.
The engine block heater must be plugged in at
least one hour to have an adequate warming
effect on the engine.
Diesel Engine Only
The engine block heater warms engine coolant
and permits quicker starts in cold weather.
Connect the heater cord to a ground-fault inter
-
rupter protected 110–115 Volt AC electrical
outlet with a grounded, three-wire extension
cord.
The engine block heater cord is routed under
the hood to the right side and can be located
just behind the grille near the headlamp. 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.
The block heater must be plugged in at least
one hour to have an adequate warming effect
on the coolant.
NOTE:
The block heater will require 110 Volts AC and
6.5 Amps to activate the heater element.
Block Heater Usage
For ambient temperatures below 0°F (-18°C),
engine block heater usage is recommended.
For ambient temperatures below –20°F
(-29°C), engine block heater usage is required.
WARNING!
Remember to disconnect the engine block
heater cord before driving. Damage to the
110-115 Volt electrical cord could cause
electrocution.
WARNING!
Remember to disconnect the engine block
heater cord before driving. Damage to the
110-115 Volt electrical cord could cause
electrocution.5

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202STARTING AND OPERATING
ENGINE BREAK-IN RECOMMENDATIONS —
GAS ENGINE
A long break-in period is not required for the
engine and drivetrain (transmission and axle) in
your vehicle.
Drive moderately during the first 300 miles
(500 km). After the initial 60 miles (100 km),
speeds up to 50 or 55 mph (80 or 90 km/h) are
desirable.
While cruising, brief full-throttle acceleration
within the limits of local traffic laws contributes
to a good break-in. Wide-open throttle accelera-
tion in low gear can be detrimental and should
be avoided.
The engine oil installed in the engine at the
factory is a high-quality energy conserving type
lubricant. Oil changes should be consistent with
anticipated climate conditions under which
vehicle operations will occur. For the recom -
mended viscosity and quality grades, refer to
“Fluids And Lubricants” in “Technical Specifica-
tions”. NOTE:
A new engine may consume some oil during its
first few thousand miles (kilometers) of opera
-
tion. This should be considered a normal part of
the break-in and not interpreted as a problem.
Please check your oil level with the engine oil
indicator often during the break in period. Add
oil as required.
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 tempera -
ture 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,
refer to “Trailer Towing” in “Starting And Oper -
ating” of the Owner’s Manual.
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).
CAUTION!
Never use Non-Detergent Oil or Straight
Mineral Oil in the engine or damage may
result.

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STARTING AND OPERATING203
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 illumi-
nated and the vehicle is moving faster than
5 mph (8 km/h); the exhaust brake will auto -
matically 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 down -
shift more aggressively in TOW/HAUL mode
when the exhaust brake is enabled to increase
brake performance. 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).
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.
CAUTION!
Use of aftermarket exhaust brakes is not
recommended and could lead to engine
damage5

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212STARTING AND OPERATING
Overdrive Operation
The automatic transmission includes an elec -
tronically 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 transmis -
sion 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 auto
-
matically 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.
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.
When To Use TOW/HAUL Mode
When driving in hilly areas, towing a trailer,
carrying a heavy load, etc., and frequent trans -
mission 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 down -
shift (for engine braking) when the throttle is
closed and/or during steady braking maneu -
vers.

TOW/HAUL Switch

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IN CASE OF EMERGENCY311
F68 –10 Amp Red AEB RACAM HTR – If Equipped (HD Only)
F69 –15 Amp Blue SCR Module – If Equipped (HD Only)
F70 –30 Amp GreenFuel Pump Motor / K09 RLY Coil Feed (Cummins Diesel) –
If Equipped
F71 –25 Amp ClearAmplifier / Active Noise Cancelation – If Equipped (HD
Only)
F72 –10 Amp RedPCM / DC/DC Converter Voltage– If Equipped (DS 1500
Only)
F73 –20 Amp Yellow Fuel Transfer Pump (Rear Tank) – If Equipped (HD Only)
F74 –20 Amp Yellow Brake Vacuum Pump Gas/Diesel – If Equipped (DS 1500
Only)
F74 –10 Amp Red Backup Alarm – If Equipped (HD Only)
F75 –10 Amp RedATMM / Coil-SCR Module RLY– If Equipped (HD Only)
Coolant Temperature Valve – If Equipped (DS 1500 Only)
F76 –10 Amp RedElectronic Stability Control (HD Only)
Brake System Module / Stop Lamp Switch / Electric Park
Brake / Clutch Pedal Switch (DS 1500 Only)
F77 –10 Amp Red
Drivetrain Control Module / Front Axle Disconnect Module /
TCM/ STOM (HD Only)

Drivetrain Control Module / ELSD / Front Axle Disconnect
Module / Transmission Control Relay / RDM / Power Take
Off Unit – If Equipped (DS 1500 Only)
Cavity
Cartridge Fuse Micro Fuse Description
6

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322IN CASE OF EMERGENCY
NOTE:
There are steps that you can take to slow down
an impending overheat condition:
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.
GEAR SELECTOR OVERRIDE — 6–SPEED
TRANSMISSION
If a malfunction occurs and the gear selector
cannot be moved out of the PARK position, you
can use the following procedure to temporarily
move the gear selector:

1. Turn the engine OFF.

2. Firmly apply the parking brake.
3. Tilt the steering wheel to the full up position.
4. Press and maintain firm pressure on the
brake pedal. 5. Insert a screwdriver or similar tool into the
access port (ringed circle) on the bottom of
the steering column, and push and hold the
override release lever up.

Gear Selector Override Access Port Location Gear Selector Override Access Port
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.
CAUTION!
Driving with a hot cooling system could
damage your vehicle. If the temperature
gauge reads HOT (H), pull over and stop the
vehicle. Idle the vehicle with the air
conditioner turned off until the pointer drops
back into the normal range. If the pointer
remains on HOT (H), and you hear continuous
chimes, turn the engine off immediately and
call for service.

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