2020 Ram 3500 Chassis Cab ECU

SAFETY181
(Continued)
(Continued)
Air Bag Warning Light
The Air Bag warning light will turn on for four
to eight seconds as a bulb check when the igni
-
tion switch is first placed in ON/RUN. If the light
is either not on during starting, stays on, or
turns on while driving, have the system
inspected at an authorized dealer as soon as
possible. After the bulb check, this light will illu -
minate with a single chime when a fault with the
Air Bag System has been detected. It will stay on
until the fault is removed. If the light comes on
intermittently or remains on while driving, have
an authorized dealer service the vehicle imme -
diately.
Refer to “Occupant Restraint Systems” in
“Safety” for further information.
Defroster
Check operation by selecting the defrost mode
and place the blower control on high speed. You
should be able to feel the air directed against
the windshield. See an authorized dealer for
service if your defroster is inoperable.
Floor Mat Safety Information
Always use floor mats designed to fit your
vehicle. Only use a floor mat that does not inter -
fere with the operation of the accelerator, brake
or clutch pedals. Only use a floor mat that is
securely attached using the floor mat fasteners
so it cannot slip out of position and interfere
with the accelerator, brake or clutch pedals or
impair safe operation of your vehicle in other
ways.
WARNING!
An improperly attached, damaged, folded, or
stacked floor mat, or damaged floor mat
fasteners may cause your floor mat to
interfere with the accelerator, brake, or clutch
pedals and cause a loss of vehicle control. To
prevent SERIOUS INJURY or DEATH:
ALWAYS securely attach your floor mat
using the floor mat fasteners. DO NOT
install your floor mat upside down or turn
your floor mat over. Lightly pull to confirm
mat is secured using the floor mat
fasteners on a regular basis.
ALWAYS REMOVE THE EXISTING FLOOR
MAT FROM THE VEHICLE before
installing any other floor mat. NEVER install
or stack an additional floor mat on top of an
existing floor mat.
ONLY install floor mats designed to fit your
vehicle. NEVER install a floor mat that
cannot be properly attached and secured to
your vehicle. If a floor mat needs to be
replaced, only use a FCA approved floor
mat for the specific make, model, and year
of your vehicle.
ONLY use the driver’s side floor mat on the
driver’s side floor area. To check for inter -
ference, with the vehicle properly parked
with the engine off, fully depress the accel -
erator, the brake, and the clutch pedal (if
present) to check for interference. If your
floor mat interferes with the operation of
any pedal, or is not secure to the floor,
remove the floor mat from the vehicle and
place the floor mat in your trunk.
ONLY use the passenger’s side floor mat on
the passenger’s side floor area.
WARNING! (Continued)
4

2020_RAM_CHASSIS_CAB_OM_USA=GUID-6C67832B-7839-4CCF-BEFC-CDF988F949EA=1=en=.book Page 181

182SAFETY
Periodic Safety Checks You Should Make
Outside The Vehicle
Tires
Examine tires for excessive tread wear and
uneven wear patterns. Check for stones, nails,
glass, or other objects lodged in the tread or
sidewall. Inspect the tread for cuts and cracks.
Inspect sidewalls for cuts, cracks, and bulges.
Check the wheel bolts for tightness. Check the
tires (including spare) for proper cold inflation
pressure.
Lights
Have someone observe the operation of brake
lights and exterior lights while you work the
controls. Check turn signal and high beam indi -
cator 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.
ALWAYS make sure objects cannot fall or
slide into the driver’s side floor area when
the vehicle is moving. Objects can become
trapped under accelerator, brake, or clutch
pedals and could cause a loss of vehicle
control.
NEVER place any objects under the floor
mat (e.g., towels, keys, etc.). These objects
could change the position of the floor mat
and may cause interference with the accel -
erator, brake, or clutch pedals.
If the vehicle carpet has been removed and
re-installed, always properly attach carpet
to the floor and check the floor mat
fasteners are secure to the vehicle carpet.
Fully depress each pedal to check for inter -
ference with the accelerator, brake, or
clutch pedals then re-install the floor mats.
It is recommended to only use mild soap
and water to clean your floor mats. After
cleaning, always check your floor mat has
been properly installed and is secured to
your vehicle using the floor mat fasteners
by lightly pulling mat.
WARNING! (Continued)

2020_RAM_CHASSIS_CAB_OM_USA=GUID-6C67832B-7839-4CCF-BEFC-CDF988F949EA=1=en=.book Page 182

STARTING AND OPERATING197
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 automati -
cally enter an emissions operating mode that
will increase the engine idle speed to 900 RPM
(1,050 RPM for Chassis Cab). 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 kmh). 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 automati
-
cally 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.
5

2020_RAM_CHASSIS_CAB_OM_USA=GUID-6C67832B-7839-4CCF-BEFC-CDF988F949EA=1=en=.book Page 197

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

2020_RAM_CHASSIS_CAB_OM_USA=GUID-6C67832B-7839-4CCF-BEFC-CDF988F949EA=1=en=.book Page 201

STARTING AND OPERATING205
(Continued)
(Continued)
AUTOMATIC TRANSMISSION
Do not leave the key fob in or near the
vehicle, or in a location accessible to chil-
dren, and do not leave 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.
Be sure the parking brake is fully disen
-
gaged before driving; failure to do so can
lead to brake failure and a collision.
Always fully apply the parking brake when
leaving your vehicle or it may roll and cause
damage or injury. Also, be certain to leave
the transmission in PARK. Failure to do so
may cause the vehicle to roll and cause
damage or injury.
CAUTION!
If the Brake System Warning Light remains on
with the parking brake released, a brake
system malfunction is indicated. Have the
brake system serviced by an authorized
dealer immediately.
WARNING! (Continued)
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 accel -
erate 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 indicator 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 mode) the trans -
mission is locked in PARK, securing the
vehicle against unwanted movement.
When leaving the vehicle, always make
sure the ignition is in the OFF mode,
remove the key fob from the vehicle, and
lock the vehicle.
Never use the PARK position as a substi -
tute for the parking brake. Always apply the
parking brake fully when exiting the vehicle
to guard against vehicle movement and
possible injury or damage.
WARNING! (Continued)
5

2020_RAM_CHASSIS_CAB_OM_USA=GUID-6C67832B-7839-4CCF-BEFC-CDF988F949EA=1=en=.book Page 205

208STARTING AND OPERATING
(Continued)
(Continued)
(Continued)
NOTE:
On four-wheel drive vehicles be sure that the
transfer case is in a drive position.
When exiting the vehicle, always:
Apply the parking brake.
Shift the transmission into PARK.
Turn the engine off.
Remove the key fob.
WARNING!
Never use the PARK position as a substi
-
tute for the parking brake. Always apply the
parking brake fully when exiting the vehicle
to guard against vehicle movement and
possible injury or damage.
Your vehicle could move and injure you and
others if it is not in PARK. Check by trying to
move the gear selector out of PARK with the
brake pedal released. Make sure the trans -
mission is in PARK before exiting the
vehicle.
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 accel -
erate 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.
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 mode), the trans -
mission is locked in PARK, securing the
vehicle against unwanted movement.
When leaving the vehicle, always make
sure the ignition is in the OFF mode,
remove the key fob from the vehicle, and
lock the vehicle.
WARNING! (Continued)
Never leave children alone in a vehicle, or
with access to an unlocked vehicle.
Allowing children to be in a vehicle unat -
tended 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 transmission 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 (in 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.
CAUTION!
Before moving the transmission gear
selector out of PARK, you must turn the igni -
tion to the ON/RUN mode, and also press
the brake pedal. Otherwise, damage to the
gear selector could result.
WARNING! (Continued)

2020_RAM_CHASSIS_CAB_OM_USA=GUID-6C67832B-7839-4CCF-BEFC-CDF988F949EA=1=en=.book Page 208

STARTING AND OPERATING215
(Continued)
The following indicators should be used to
ensure that you have properly engaged the
transmission into the PARK position:
Look at the transmission gear position
display and verify that it indicates the PARK
position (P), and is not blinking.
With brake pedal released, verify that the
gear selector will not move out of PARK.
REVERSE (R)
This range is for moving the vehicle backward.
Shift into REVERSE only after the vehicle has
come to a complete stop.
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, and turn the igni -
tion OFF. When the ignition is in the OFF
mode, the transmission is locked in PARK,
securing the vehicle against unwanted
movement.
When exiting the vehicle, always make sure
the ignition is in the OFF mode, remove the
key fob from the vehicle, and lock the
vehicle.
Never leave children alone in a vehicle, or
with access to an unlocked vehicle.
Allowing children to be in a vehicle unat -
tended 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 transmission gear
selector.
WARNING! (Continued)
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 in the
ACC or ON/RUN mode. A child could
operate power windows, other controls, or
move the vehicle.
CAUTION!
DO NOT race the engine when shifting from
PARK or NEUTRAL into another gear range,
as this can damage the drivetrain.
Before moving the transmission gear
selector out of PARK, you must start the
engine, and also press the brake pedal.
Otherwise, damage to the gear selector
could result.
WARNING! (Continued)
5

2020_RAM_CHASSIS_CAB_OM_USA=GUID-6C67832B-7839-4CCF-BEFC-CDF988F949EA=1=en=.book Page 215

STARTING AND OPERATING273
VEHICLE LOADING
Gross Vehicle Weight Rating (GVWR)
The GVWR is the total permissible weight of your
vehicle including driver, passengers, vehicle,
options and cargo. The label also specifies
maximum capacities of front and rear axle
systems (GAWR). Total load must be limited so
GVWR and front and rear GAWR are not
exceeded.
Payload
The payload of a vehicle is defined as the allow -
able load weight a truck can carry, including the
weight of the driver, all passengers, options and
cargo.
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 compo -
nents in the system with the lowest load
carrying capacity (axle, springs, tires or wheels).
Heavier axles or suspension components some -times 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 condi
-
tions, 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 speci -
fied 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.
5

2020_RAM_CHASSIS_CAB_OM_USA=GUID-6C67832B-7839-4CCF-BEFC-CDF988F949EA=1=en=.book Page 273