2020 Ram 2500 cooling

5
STARTING AND OPERATING
STARTING THE ENGINE — GAS ENGINE ......... 211Automatic Transmission ............................211
Tip Start Feature .......................................211
Keyless Enter-N-Go — Ignition ...................211
Normal Starting Using ENGINE START/
STOP Button ...............................................212 Cold Weather Operation (Below –22°F Or
−30°C) ......................................................215 After Starting ..............................................215
STARTING THE ENGINE — DIESEL ENGINE..... 215
Automatic Transmission ............................215
Keyless Enter-N-Go — Ignition ...................216
Extreme Cold Weather...............................218
Normal Starting Procedure — Engine
Manifold Air Temperature Above 66° F
(19° C)........................................................ 218 Starting Procedure — Engine Manifold Air
Temperature 0°F To 66°F (–18°C to
19°C) ..........................................................219 Starting Procedure — Engine Manifold Air
Temperature Below 0°F (-18°C) ..............220 Starting Fluids ............................................221 NORMAL OPERATION — DIESEL ENGINE ........221
Cold Weather Precautions ........................ 222
Engine Idling ............................................. 224
Noise........................................................... 225
Stopping The Engine ................................. 225
Idle Shutdown ............................................ 226
Programmable Maximum Vehicle
Speed ......................................................... 226 Operating Precautions............................... 226
Cooling System Tips .................................. 226
ENGINE BLOCK HEATER — GAS ENGINE (IF
EQUIPPED) ..........................................................227
ENGINE BLOCK HEATER — DIESEL ENGINE (IF
EQUIPPED) ......................................................... 227
Block Heater Usage ................................... 228
ENGINE BREAK-IN RECOMMENDATIONS — GAS
ENGINE ................................................................ 228
ENGINE BREAK-IN RECOMMENDATIONS —
DIESEL ENGINE...................................................228
PARKING BRAKE ............................................... 229
DIESEL EXHAUST BRAKE — ENGINE BRAKING
(IF EQUIPPED) ....................................................230
AUTOMATIC TRANSMISSION ........................... 231
Ignition Park Interlock ............................... 232
Brake/Transmission Shift Interlock
System ....................................................... 232 Eight-Speed Automatic Transmission — If
Equipped .................................................... 233 Six-Speed Automatic Transmission — If
Equipped .................................................... 237
AUXILIARY SWITCHES — IF EQUIPPED ........... 243
ACTIVE NOISE CANCELLATION ........................ 243
FOUR-WHEEL DRIVE OPERATION —
IF EQUIPPED ...................................................... 244
Four-Position Electronically Shifted Transfer
Case — If Equipped ................................... 244
Manually Shifted Transfer Case —
If Equipped ................................................. 247
AIR SUSPENSION SYSTEM — IF EQUIPPED.... 250
Description ................................................. 250
Air Suspension Modes .............................. 251
Instrument Cluster Display Messages ..... 251
Operation ................................................... 251
AXLE LOCKER SYSTEM — POWER WAGON
MODELS ONLY (IF EQUIPPED) ......................... 252
STABILIZER/SWAY BAR SYSTEM — POWER
WAGON ONLY .................................................... 253

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8
ENHANCED ACCIDENT RESPONSE SYSTEM
(EARS) ................................................................ 371
EVENT DATA RECORDER (EDR) ....................... 371
BULB REPLACEMENT ........................................ 372 Replacement Bulbs ...................................372
Replacing Exterior Bulbs ...........................374
SERVICING AND MAINTENANCE
SCHEDULED SERVICING — GAS ENGINE ....... 380Maintenance Plan — Gasoline Engine......380
Heavy Duty Use Of The Vehicle ................. 384
SCHEDULED SERVICING— DIESEL ENGINE .... 384
Oil Change Indicator System — Cummins
Diesel ..........................................................385 Perform Service Indicator — Cummins
Diesel ..........................................................385
Maintenance Plan — Cummins Diesel
Engine ........................................................ 386
ENGINE COMPARTMENT .................................. 391
6.4L Engine ...............................................391
6.7L Diesel Engine — Six-Speed 68RFE ..392
6.7L Diesel Engine — Six-Speed
AS69RC HD ................................................393 Checking Oil Level — Gas Engine .............394
Checking Oil Level — Diesel Engine ..........394
Adding Washer Fluid..................................394
Maintenance-Free Battery .......................395
Pressure Washing ......................................395 DEALER SERVICE ..............................................396
Engine Oil .................................................. 396
Engine Oil Filter .......................................... 398
Engine Air Cleaner Filter............................ 398
Air Conditioner Maintenance .................... 400
Accessory Drive Belt Inspection ............... 403
Draining Fuel/Water Separator Filter —
Diesel Engine ............................................ 403 Engine Mounted Fuel Filter Replacement —
Diesel Engine ............................................. 405 Underbody Mounted Fuel Filter
Replacement — Diesel Engine .................. 406 Priming If The Engine Has Run Out Of
Fuel — Diesel Engine ................................. 407 Intervention Regeneration Strategy —
Message Process Flow ............................. 407 Diesel Exhaust Fluid .................................. 408
Body Lubrication ........................................ 408
Windshield Wiper Blades .......................... 409
Exhaust System ........................................ 410
Cooling System ......................................... 411
Charge Air Cooler — Inter-Cooler .............. 415
Brake System ............................................ 415
Automatic Transmission............................ 416
Rear Axle And 4x4 Front Driving Axle Fluid
Level .......................................................... 418 Transfer Case ............................................ 419
Noise Control System Required
Maintenance & Warranty ......................... 419 HOISTING ........................................................... 422
TIRES ................................................................... 422
Tire Safety Information.............................. 422
Tires — General Information .................... 428
Tire Types ................................................... 432
Spare Tires — If Equipped ......................... 433
Wheel And Wheel Trim Care ..................... 434
Tire Chains And Traction Devices ............ 435
Tire Rotation Recommendations ............. 436
DEPARTMENT OF TRANSPORTATION UNIFORM
TIRE QUALITY GRADES .................................... 438
Treadwear .................................................. 438
Traction Grades ......................................... 438
Temperature Grades ................................. 438
STORING THE VEHICLE ..................................... 439
BODYWORK ........................................................ 439
Protection From Atmospheric Agents....... 439
Body And Underbody Maintenance .......... 439
Preserving The Bodywork.......................... 440
INTERIORS ......................................................... 442
Seats And Fabric Parts .............................. 442
Plastic And Coated Parts........................... 442
Leather Parts ............................................. 443
Glass Surfaces .......................................... 443

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68GETTING TO KNOW YOUR VEHICLE
Climate Control Functions
A/C (Air Conditioning)
The Air Conditioning (A/C) button allows the
operator to manually activate or deactivate the
air conditioning system. When the air condi -
tioning system is turned on, cool dehumidified
air will flow through the outlets into the cabin.
For improved fuel economy, press the A/C
button to turn off the air conditioning and manu -
ally adjust the blower and airflow mode settings.
Also, make sure to select only Panel, Bi-Level, or
Floor modes.
NOTE:
For Manual Climate Controls, if the system is
in Mix, Floor or Defrost Mode, the A/C can be
turned off, but the A/C system shall remain
active to prevent fogging of the windows.
If fog or mist appears on the windshield or
side glass, select Defrost mode, and increase
blower speed if needed.
If your air conditioning performance seems
lower than expected, check the front of the
A/C condenser (located in front of the radi -
ator), for an accumulation of dirt or insects. Clean with a gentle water spray from the front
of the radiator and through the condenser.
MAX A/C
MAX A/C sets the control for maximum cooling
performance.
Press and release to toggle between MAX A/C
and the prior settings. The button illuminates
when MAX A/C is on.
In MAX A/C, the blower level and mode position
can be adjusted to desired user settings.
Pressing other settings will cause the MAX A/C
operation to switch to the selected setting and
MAX A/C to exit.
Recirculation
In cold weather, use of Recirculation mode may
lead to excessive window fogging. The Recircu -
lation feature may be unavailable (button on
the touchscreen greyed out) if conditions exist
that could create fogging on the inside of the
windshield.
On systems with Manual Climate Controls, if
equipped, the Recirculation mode is not
allowed in Defrost mode to improve window
clearing operation. Recirculation is disabled
automatically if this mode is selected. Attempting to use Recirculation while in this
mode causes the LED in the control button to
blink and then turns off.
Automatic Temperature Control (ATC)
Automatic Operation

1. Push the AUTO button on the faceplate, or the AUTO button on the touchscreen on the
Automatic Temperature Control (ATC)
Panel.

2. Next, adjust the temperature you would like the system to maintain by adjusting the
driver and passenger temperature control
buttons. Once the desired temperature is
displayed, the system will achieve and auto -
matically maintain that comfort level.
3. When the system is set up for your comfort level, it is not necessary to change the
settings. You will experience the greatest
efficiency by simply allowing the system to
function automatically.

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GETTING TO KNOW YOUR VEHICLE69
NOTE:
It is not necessary to move the temperature
settings for cold or hot vehicles. The system
automatically adjusts the temperature,
mode, and blower speed to provide comfort
as quickly as possible.
The temperature can be displayed in U.S. or
Metric units by selecting the U.S./Metric
customer-programmable feature. Refer to
the “Uconnect Settings” in “Multimedia” for
further information.
To provide you with maximum comfort in the
Automatic mode during cold start-ups, the
blower fan will remain on low until the engine
warms up. The blower will increase in speed
and transition into Auto mode.
Manual Operation Override
This system offers a full complement of manual
override features. The AUTO symbol in the front
ATC display will be turned off when the system
is being used in the manual mode.
Operating Tips
NOTE:
Refer to the chart at the end of this section for
suggested control settings for various weather
conditions.
Summer Operation
The engine cooling system must be protected
with a high-quality antifreeze coolant to provide
proper corrosion protection and to protect
against engine overheating. OAT coolant
(conforming to MS.90032) is recommended.
Winter Operation
To ensure the best possible heater and
defroster performance, make sure the engine
cooling system is functioning properly and the
proper amount, type, and concentration of
coolant is used. Use of the Air Recirculation
mode during Winter months is not recom -
mended, because it may cause window fogging.
Vacation/Storage
Before you store your vehicle, or keep it out of
service (i.e., vacation) for two weeks or more,
run the air conditioning system at idle for about
five minutes, in fresh air with the blower setting
on high. This will ensure adequate system lubri -cation to minimize the possibility of compressor
damage when the system is started again.
Window Fogging
Vehicle windows tend to fog on the inside in
mild, rainy, and/or humid weather. To clear the
windows, select Defrost or Mix mode and
increase the front blower speed. Do not use the
Recirculation mode without A/C for long
periods, as fogging may occur.
CAUTION!
Failure to follow these cautions can cause
damage to the heating elements:
Use care when washing the inside of the
rear window. Do not use abrasive window
cleaners on the interior surface of the
window. Use a soft cloth and a mild
washing solution, wiping parallel to the
heating elements. Labels can be peeled off
after soaking with warm water.
Do not use scrapers, sharp instruments, or
abrasive window cleaners on the interior
surface of the window.
Keep all objects a safe distance from the
window.
2

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GETTING TO KNOW YOUR INSTRUMENT PANEL109
Base / Midline Instrument Cluster
Descriptions — Gas Engine

1. Tachometer

Indicates the engine speed in revolutions
per minute (RPM x 1000).
2. Voltmeter
When the vehicle is in the RUN state, the gauge indicates the electrical system
voltage. The pointer should stay within
the normal range if the battery is
charged. If the pointer moves to either
extreme left or right and remains there
during normal driving, the electrical
system should be serviced.
3. Instrument Cluster Display
When the appropriate conditions exist, this display shows the instrument cluster
display messages. Refer to “Instrument
Cluster Display” in “Getting To Know Your
Instrument Panel” for further informa -
tion. 4. Oil Pressure Gauge
The pointer should always indicate the oil
pressure when the engine is running. A
continuous high or low reading under
normal driving conditions may indicate a
lubrication system malfunction. Imme -
diate service should be obtained from an
authorized dealer.
5. Speedometer
Indicates vehicle speed.
6. Fuel Gauge
The pointer shows the level of fuel in the fuel tank when the ignition is in the ON/
RUN position.
 The fuel pump symbol points to the
side of the vehicle where the fuel door is
located.
Refer to “Refueling The Vehicle — Gas
Engine” in “Starting And Operating” for
further information. 7. Temperature Gauge
The gauge pointer shows engine coolant
temperature. The pointer positioned
within the normal range indicates that
the engine cooling system is operating
satisfactorily.
The gauge pointer will likely indicate a higher temperature when driving in hot
weather, up mountain grades, or when
towing a trailer. It should not be allowed
to exceed the upper limits of the normal
operating range.
WARNING!
A hot engine cooling system is dangerous.
You or others could be badly burned by steam
or boiling coolant. You may want to call an
authorized dealer for service if your vehicle
overheats. If you decide to look under the
hood yourself, refer to the warnings under
“Cooling System Pressure Cap” in see
“Servicing And Maintenance” for further
information.
3

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110GETTING TO KNOW YOUR INSTRUMENT PANEL
CAUTION!
Driving with a hot engine cooling system
could damage your vehicle. If the
temperature gauge reads “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 the “H,” turn the engine off
immediately and call an authorized dealer for
service.

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112GETTING TO KNOW YOUR INSTRUMENT PANEL
Premium Instrument Cluster Descriptions —
Gas Engine

1. Tachometer

Indicates the engine speed in revolutions
per minute (RPM x 1000).
2. Instrument Cluster Display
When the appropriate conditions exist, this display shows the instrument cluster
display messages. Refer to “Instrument
Cluster Display” in “Getting To Know Your
Instrument Panel” for further informa -
tion.
3. Speedometer
Indicates vehicle speed.
4. Fuel Gauge
The pointer shows the level of fuel in the fuel tank when the ignition is in the ON/
RUN position.
 The fuel pump symbol points to the
side of the vehicle where the fuel door is
located. Refer to “Refueling The Vehicle — Gas
Engine” in “Starting And Operating” for
further information.
5. Temperature Gauge
The gauge pointer shows engine coolant temperature. The pointer positioned
within the normal range indicates that
the engine cooling system is operating
satisfactorily.
The gauge pointer will likely indicate a higher temperature when driving in hot
weather, up mountain grades, or when
towing a trailer. It should not be allowed
to exceed the upper limits of the normal
operating range.
WARNING!
A hot engine cooling system is dangerous.
You or others could be badly burned by steam
or boiling coolant. You may want to call an
authorized dealer for service if your vehicle
overheats. If you decide to look under the
hood yourself, refer to the warnings under
“Cooling System Pressure Cap” in see
“Servicing And Maintenance” for further
information.
CAUTION!
Driving with a hot engine cooling system
could damage your vehicle. If the
temperature gauge reads “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 the “H,” turn the engine off
immediately and call an authorized dealer for
service.

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114GETTING TO KNOW YOUR INSTRUMENT PANEL
Base Instrument Cluster Descriptions —
Diesel Engine

1. Tachometer

Indicates the engine speed in revolutions
per minute (RPM x 1000).
2. Engine Coolant Temperature
This gauge shows the engine coolant temperature. The gauge pointer will likely
show higher temperatures when driving
in hot weather, up mountain grades, or in
heavy stop and go traffic. If the red
Warning Light turns on while driving,
safely bring the vehicle to a stop, and
turn off the engine. DO NOT operate the
vehicle until the cause is corrected. 3. Instrument Cluster Display
When the appropriate conditions exist,
this display shows the instrument cluster
display messages. Refer to “Instrument
Cluster Display” in “Getting To Know Your
Instrument Panel” for further informa -
tion. 4. Oil Pressure Gauge
The pointer should always indicate some
oil pressure when the engine is running.
A continuous high or low reading under
normal driving conditions may indicate a
lubrication system malfunction. Imme -
diate service should be obtained from an
authorized dealer.
5. Speedometer
Indicates vehicle speed.
6. Fuel Gauge
The pointer shows the level of fuel in the fuel tank when the ignition switch is in
the ON/RUN position.
 The fuel pump symbol points to the
side of the vehicle where the fuel filler
door is located.
Refer to “Refueling The Vehicle — Gas
Engine” in “Starting And Operating” for
further information.
WARNING!
A hot engine cooling system is dangerous.
You or others could be badly burned by steam
or boiling coolant. You may want to call an
authorized dealer for service if your vehicle
overheats.
CAUTION!
Driving with a hot engine cooling system
could damage your vehicle. If the
temperature gauge reads greater “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 the “h,” turn the
engine off immediately and call an authorized
dealer for service.

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