2020 Ram 3500 warning light

280STARTING AND OPERATING
SPEED CONTROL
When engaged, the Speed Control takes over
accelerator operations at speeds greater than
20 mph (32 km/h), or 25 mph (40 km/h),
depending on the powertrain used.
The Speed Control buttons are located on the
right side of the steering wheel.

Speed Control Buttons

NOTE:
In order to ensure proper operation, the Speed
Control system has been designed to shut down if multiple speed control functions are operated
at the same time. If this occurs, the Speed
Control system can be reactivated by pushing
the Speed Control on/off button and resetting
the desired vehicle set speed.
TO ACTIVATE
Push the on/off button to activate the Speed
Control. The cruise indicator light in the
instrument cluster display will illuminate. To
turn the system off, push the on/off button a
second time. The cruise indicator light will turn
off. The system should be turned off when not in
use.
TO SET A DESIRED SPEED
Turn the Speed Control on. When the vehicle
has reached the desired speed, push the SET (-)
button and release. Release the accelerator and the vehicle will operate at the selected
speed.
NOTE:
The vehicle should be traveling at a steady
speed and on level ground before pushing the
SET (-) button.
TO VARY THE SPEED SETTING
To Increase Speed
When the Speed Control is set, you can increase
speed by pushing the RES (+) button.

The driver’s preferred units can be selected
through the instrument panel settings (if
equipped). Refer to “Getting To Know Your
Instrument Panel” for more information. The
speed increment shown is dependent on the
chosen speed unit of U.S. (mph) or Metric (km/h):

U.S. Speed (mph)

Pushing the RES (+) button once will result in
a 1 mph increase in set speed. Each subse -
quent tap of the button results in an increase
of 1 mph.
If the button is continually pushed, the set
speed will continue to increase until the
button is released, then the new set speed
will be established.
1 — On/Off Button
2 — RES (+)
3 — SET (-)
4 — CANCEL
WARNING!
Leaving the Speed Control system on when
not in use is dangerous. You could
accidentally set the system or cause it to go
faster than you want. You could lose control
and have an accident. Always leave the
system off when you are not using it.

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STARTING AND OPERATING281
Metric Speed (km/h)
Pushing the RES (+) button once will result in
a 1 km/h increase in set speed. Each subse -
quent tap of the button results in an increase
of 1 km/h.
If the button is continually pushed, the set
speed will continue to increase until the
button is released, then the new set speed
will be established.
To Decrease Speed
When the Speed Control is set, you can
decrease speed by pushing the SET (-) button.

The driver’s preferred units can be selected
through the instrument panel settings (if
equipped). Refer to “Getting To Know Your
Instrument Panel” for more information. The
speed decrement shown is dependent on the
chosen speed unit of U.S. (mph) or Metric (km/h):

U.S. Speed (mph)
Pushing the SET (-) button once will result in
a 1 mph decrease in set speed. Each subse -
quent tap of the button results in a decrease
of 1 mph.
If the button is continually pushed, the set
speed will continue to decrease until the
button is released, then the new set speed
will be established. Metric Speed (km/h)

Pushing the SET (-) button once will result in
a 1 km/h decrease in set speed. Each subse -
quent tap of the button results in a decrease
of 1 km/h.
If the button is continually pushed, the set
speed will continue to decrease until the
button is released, then the new set speed
will be established.
TO ACCELERATE FOR PASSING
Press the accelerator as you would normally.
When the pedal is released, the vehicle will
return to the set speed.
Using Speed Control On Hills
The transmission may downshift on hills to
maintain the vehicle set speed.
NOTE:
The Speed Control system maintains speed up
and down hills. A slight speed change on
moderate hills is normal.
On steep hills, a greater speed loss or gain may
occur so it may be preferable to drive without
Speed Control.
TO RESUME SPEED
To resume a previously set speed, push the RES
(+) button and release. Resume can be used at
any speed above 20 mph (32 km/h).
TO DEACTIVATE
A soft tap on the brake pedal, pushing the
CANCEL button, or normal brake pressure while
slowing the vehicle will deactivate the Speed
Control without erasing the set speed from
memory.
Pushing the on/off button, or placing the
ignition in the OFF position, erases the set
speed from memory.
WARNING!
Speed Control can be dangerous where the
system cannot maintain a constant speed.
Your vehicle could go too fast for the
conditions, and you could lose control and
have an accident. Do not use Speed Control
in heavy traffic or on roads that are winding,
icy, snow-covered or slippery.
5

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282STARTING AND OPERATING
(Continued)
The following conditions will also deactivate the
Speed Control without erasing the set speed
from memory:
Vehicle parking brake is applied
Stability event occurs
Gear selector is moved out of DRIVE
Engine overspeed occurs
ADAPTIVE CRUISE CONTROL (ACC) — IF
EQUIPPED
Adaptive Cruise Control (ACC) increases the
driving convenience provided by cruise control
while traveling on highways and major
roadways. However, it is not a safety system
and not designed to prevent collisions. Speed
Control function performs differently. Please
refer to the proper section within this chapter.
ACC will allow you to keep cruise control
engaged in light to moderate traffic conditions
without the constant need to reset your cruise
control. ACC utilizes a radar sensor and a
forward facing camera designed to detect a
vehicle directly ahead of you. NOTE:
If the sensor does not detect a vehicle ahead
of you, ACC will maintain a fixed set speed.
If the ACC sensor detects a vehicle ahead,
ACC will apply limited braking or accelerate
(not to exceed the original set speed) auto
-
matically to maintain a preset following
distance, while matching the speed of the
vehicle ahead.
The Cruise Control system has two control
modes:
Adaptive Cruise Control mode for main -
taining an appropriate distance between
vehicles.
Normal (Fixed Speed) Cruise Control mode
for cruising at a constant preset speed. For
additional information, refer to “Normal
(Fixed Speed) Cruise Control Mode” in this
section.
NOTE:
Normal (Fixed Speed) Cruise Control will not
react to preceding vehicles. Always be aware of
the mode selected. You can change the mode by using the Cruise
Control buttons. The two control modes
function differently. Always confirm which mode
is selected.
WARNING!
Adaptive Cruise Control (ACC) is a conve
-
nience system. It is not a substitute for
active driver involvement. It is always the
driver’s responsibility to be attentive of
road, traffic, and weather conditions,
vehicle speed, distance to the vehicle
ahead; and, most importantly, brake opera -
tion to ensure safe operation of the vehicle
under all road conditions. Your complete
attention is always required while driving to
maintain safe control of your vehicle.
Failure to follow these warnings can result
in a collision and death or serious personal
injury.
The ACC system:
Does not react to pedestrians,
oncoming vehicles, and stationary
objects (e.g., a stopped vehicle in a
traffic jam or a disabled vehicle).

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288STARTING AND OPERATING
The system automatically defaults to the
longest distance setting. To decrease the
distance setting, push the Distance Button and
release. Each time the button is pushed, the
distance setting decreases by one bar. Once the
shortest setting is reached, if the button is
pushed again it will reset to the default setting
(longest).
If there is no vehicle ahead, the vehicle will
maintain the set speed. If a slower moving
vehicle is detected in the same lane, the
instrument cluster displays the ACC Set With
Target Indicator Light, and the system adjusts
vehicle speed automatically to maintain the
distance setting, regardless of the set speed.
The vehicle will then maintain the set distance
until:
The vehicle ahead accelerates to a speed
above the set speed.
The vehicle ahead moves out of your lane or
view of the sensor.
The distance setting is changed.
The system disengages. (Refer to “Activating
Adaptive Cruise Control (ACC)” in this
chapter. The maximum braking applied by ACC is limited;
however, the driver can always apply the brakes
manually, if necessary.
NOTE:
The brake lights will illuminate whenever the
ACC system applies the brakes.
A Proximity Warning will alert the driver if ACC
predicts that its maximum braking level is not
sufficient to maintain the set distance. If this
occurs, a visual alert “BRAKE” will flash in the
instrument cluster display and a chime will
sound while ACC continues to apply its
maximum braking capacity.

Brake Alert
NOTE:
The “BRAKE!” Screen in the instrument cluster
display is a warning for the driver to take action
and does not necessarily mean that the
Forward Collision Warning system is applying
the brakes autonomously.
Trailer Detect — If Equipped

When a trailer is detected, the ACC system
automatically defaults to the longest setting (four
bars). The setting can be overridden by pushing
the Distance Button on the steering wheel.

OVERTAKE AID
When driving with ACC engaged and following a
vehicle, the system will provide an additional
acceleration up to the ACC set speed to assist in
passing the vehicle. This additional acceleration
is triggered when the driver utilizes the left turn
signal and will only be active when passing on
the left hand side.

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STARTING AND OPERATING319
(Continued)
ENGINE RUNAWAY — DIESEL ENGINE
Diesel engine runaway is a rare condition
affecting diesel engines, where the engine
consumes its own lubrication oil and runs at
higher and higher RPM until it overspeeds to a
point where it destroys itself due to either
mechanical failure or engine seizure through
lack of lubrication.
REFUELING THE VEHICLE — GAS ENGINE
The fuel filler cap (gas cap) is located behind the
fuel filler door, on the left side of the vehicle.
Open the fuel door and remove the fuel filler cap
by turning it counter-clockwise.
Fuel Filler Cap

NOTE:
When removing the fuel filler cap, lay the cap
tether in the hook, located on the fuel filler door.
NOTE:
When the fuel nozzle “clicks” or shuts off, the
fuel tank is full.
WARNING!
In case of engine runaway due to flammable
fumes from fuel spills or turbocharger oil
leaks being sucked into the engine, do the
following to help avoid personal injury and/or
vehicle damage:
1. Turn the ignition switch to the OFF position.
2. Using a CO2 or dry chemical type fire
extinguisher, direct the spray from the fire
extinguisher into the grille on the driver side
so that the spray enters the engine air intake.
The inlet for the engine air intake is located
behind the drivers side headlamp and
receives air through the grille.
WARNING!
Never have any smoking materials lit in or
near the vehicle when the gas cap is
removed or the tank is being filled.
Never add fuel to the vehicle when the
engine is running.
A fire may result if gasoline is pumped into
a portable container that is inside of a
vehicle. You could be burned. Always place
gas containers on the ground while filling.
CAUTION!
Damage to the fuel system or emissions
control system could result from using an
improper fuel tank filler tube cap.
A poorly fitting fuel filler cap could let impu-
rities into the fuel system.
A poorly fitting fuel filler cap may cause the
“Malfunction Indicator Light (MIL)” to turn
on.
To avoid fuel spillage and overfilling, do not
“top off” the fuel tank after filling. When the
fuel nozzle “clicks” or shuts off, the fuel
tank is full.
WARNING! (Continued)
5

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STARTING AND OPERATING321
(Continued)

Fill Locations And Funnel Usage

NOTE:
Ensure funnel is inserted fully to hold flapper
door open.
3. Pour fuel into funnel opening.
4. Remove funnel from filler pipe, clean off prior to putting back in the jack kit.
DIESEL EXHAUST FLUID
Your vehicle is equipped with a Selective
Catalytic Reduction (SCR) system to meet the
very stringent diesel emissions standards
required by the Environmental Protection
Agency.
The purpose of the SCR system is to reduce
levels of NOx (oxides of nitrogen emitted from
engines) that are harmful to our health and the
environment to a near-zero level. A small
quantity of Diesel Exhaust Fluid (DEF) is injected into the exhaust upstream of a catalyst
where, when vaporized, it converts
smog-forming nitrogen oxides (NOx) into
harmless nitrogen (N2) and water vapor (H2O),
two natural components of the air we breathe.
You can operate with the comfort that your
vehicle is contributing to a cleaner, healthier
world environment for this and generations to
come.
System Overview
This vehicle is equipped with a Diesel Exhaust
Fluid (DEF) injection system and a Selective
Catalytic Reduction (SCR) catalyst to meet the
emission requirements.
The DEF injection system consists of the
following components:
DEF tank
DEF pump
DEF injector
Electronically-heated DEF lines
DEF control module
NOx sensors
1 — Diesel Exhaust Fluid (DEF) Fill Location
2 — Emergency Diesel Fuel Fill Funnel
3 — Diesel Fuel Fill Location
WARNING!
Never have any smoking materials lit in or
near the vehicle when the fuel door is open
or the tank is being filled.
Never add fuel when the engine is running.
This is in violation of most state and federal
fire regulations and may cause the
“Malfunction Indicator Light” to turn on.
A fire may result if fuel is pumped into a
portable container that is inside of a
vehicle. You could be burned. Always place
fuel containers on the ground while filling.
CAUTION!
To avoid fuel spillage and overfilling, do not
“top off” the fuel tank after filling.
WARNING!
(Continued)
5

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STARTING AND OPERATING327

With Weight-Distributing Hitch (Correct) Without Weight-Distributing Hitch (Incorrect)
Improper Adjustment Of Weight-Distributing Hitch (Incorrect)
Recommended Distribution Hitch Adjustment
Towing With 2500/3500 Air Suspension

1. Position the truck to be ready to connect to
the trailer (do not connect the trailer).

NOTE:
Normal Ride Height (NRH) or Alternate Trailer
Height (ATH) can be used. The vehicle must
remain in the engine running position while
attaching a trailer for proper leveling of the air
suspension system. It may not be possible to
enter Alternate Trailer Height (ATH) while lightly
loaded.
2. Measure the height of the top of the front wheel opening on the fender to ground, this
is height H1.
3. Attach the trailer to the vehicle without the weight distribution bars connected.
4. Measure the height of the top of the front wheel opening on the fender to ground, this
is height H2.
WARNING!
An improperly adjusted weight distributing
hitch system may reduce handling, stability
and braking performance and could result
in a collision.
Weight distributing systems may not be
compatible with surge brake couplers.
Consult with your hitch and trailer manufac -
turer or a reputable Recreational Vehicle
dealer for additional information.
5

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332STARTING AND OPERATING
Integrated Trailer Brake Module — If
Equipped
Your vehicle may have an Integrated Trailer
Brake Module (ITBM) for Electric and Electric
Over Hydraulic (EOH) trailer brakes.
NOTE:
This module has been designed and verified
with electric trailer brakes and new electric over
hydraulic systems. Some previous EOH systems
may not be compatible with ITBM.

Integrated Trailer Brake Module (ITBM)
The user interface consists of the following:
Manual Brake Control Lever
Slide the manual brake control lever to the left
to activate power to the trailer's electric brakes
independent of the tow vehicle's brakes. If the
manual brake control lever is activated while
the brake is also applied, the greater of the two
inputs determines the power sent to the trailer
brakes.
The trailer and the vehicle’s stop lamps will
come on when braking normally with the vehicle
brake pedal. Only the trailer stop lamps will
come on when the manual brake control lever is
applied.
Trailer Brake Status Indicator Light
This light indicates the trailer electrical
connection status.
If no electrical connection is detected after the
ignition is turned on, pushing the GAIN
adjustment button or sliding the manual brake
control lever will display the GAIN setting for
10 seconds and the “Trailer Brake Status
Indicator Light” will not be displayed.
WARNING!
Do not connect trailer brakes to your
vehicle's hydraulic brake lines. It can over
-
load your brake system and cause it to fail.
You might not have brakes when you need
them and could have an accident.
Towing any trailer will increase your stop -
ping distance. When towing, you should
allow for additional space between your
vehicle and the vehicle in front of you.
Failure to do so could result in an accident.
CAUTION!
If the trailer weighs more than 1,000 lbs
(453 kg) loaded, it should have its own
brakes and they should be of adequate
capacity. Failure to do this could lead to
accelerated brake lining wear, higher brake
pedal effort, and longer stopping distances.
1 — GAIN Adjustment Button
2 — GAIN Adjustment Button
3 — Manual Brake Control Lever

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