2021 RAM 1500 engine

176STARTING AND OPERATING
TOW/HAUL mode is selected
Accelerator pedal input
Excessive 12 Volt loads
It may be possible to operate the vehicle several
consecutive times in extreme conditions and
not meet all criteria to enable an Autostop state.
TO START THE ENGINE WHILE IN
A
UTOSTOP MODE
While in DRIVE, the engine will start when the
brake pedal is released or the throttle pedal is
pressed and the transmission will automatically
reengage upon engine restart.
Conditions That Will Cause The Engine To Start
Automatically While In Autostop Mode
The engine will start automatically when:
The transmission selector is moved from
DRIVE to REVERSE, NEUTRAL, or PARK
To maintain cabin temperature near the
HVAC settings
HVAC is set to full defrost mode
12 Volt demand requires engine restart
Stop/Start OFF switch is pushed
Transfer case is in 4WD LOW
The emissions system override is present
A Stop/Start system error present
Conditions That Force An Automatic Shift To
Park While In Autostop Mode
The engine will not start automatically and the
transmission will be placed in PARK if:
The driver door is open and brake pedal
released
The driver door is open and the driver seat
belt is unbuckled
The engine hood has been opened
A Stop/Start system error present
The engine may then be restarted by moving the
transmission shift selector out of PARK (e.g. to
DRIVE) or, in some cases, only by a KEY START.
The instrument cluster will display a SHIFT OUT
OF PARK message, or a STOP/START KEY
START REQUIRED message, to indicate which
action is required Ú page 114.
TO MANUALLY TURN OFF THE STOP
S
TART SYSTEM

Stop/Start OFF Switch

Push the Stop/Start OFF switch (located on the
switch bank). The light on the switch will
illuminate. The “STOP/START OFF” message
will appear in the instrument cluster display and
the autostop mode will be disabled
Ú page 114.
NOTE:
The Stop/Start system will reset itself back to
the ON mode every time the ignition is turned
OFF and back ON.

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STARTING AND OPERATING177
TO MANUALLY TURN ON THE STOP
S
TART SYSTEM
Push the Stop/Start OFF switch (located on the
switch bank). The light on the switch will turn
off.
SYSTEM MALFUNCTION
If there is a malfunction in the Stop/Start
system, the system will not shut down the
engine. A “SERVICE STOP/START SYSTEM”
message will appear in the instrument cluster
display Ú page 126.
The system will need to be checked by an
authorized dealer.
CRUISE CONTROL SYSTEMS — IF EQUIPPED
Your vehicle may be equipped with the Cruise
Control system, or the Adaptive Cruise Control
(ACC) system:
Cruise Control for cruising at a constant
preset speed.
Adaptive Cruise Control (ACC) for maintaining
a set distance between you and the vehicle
ahead using Fixed Speed Cruise Control to
automatically adjust the preset speed. NOTE:
In vehicles equipped with ACC, if an ACC
distance is not set, Fixed Speed Cruise Control
will not detect vehicles directly ahead of you.
Always be aware of the mode selected.
CRUISE CONTROL — IF EQUIPPED
When engaged, the Cruise Control takes over
accelerator operations at speeds greater than
20 mph (32 km/h).
The Cruise Control buttons are located on the
right side of the steering wheel.

Cruise Control Buttons
NOTE:
In order to ensure proper operation, the Cruise
Control system has been designed to shut down
if multiple Cruise Control functions are operated
at the same time. If this occurs, the Cruise
Control system can be reactivated by pushing
the Cruise Control on/off button and resetting
the desired vehicle set speed.
To Activate
Push the on/off button to activate the Cruise
Control. The cruise indicator light in the
instrument cluster display will illuminate. To
turn the system off, push the on/off button a 1 — CANC/Cancel
2 — SET (+)/Accel
3 — On/Off
4 — RES/Resume
5 — SET (-)/Decel
WARNING!
Cruise 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 Cruise Control
in heavy traffic or on roads that are winding,
icy, snow-covered or slippery.
4

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STARTING AND OPERATING179
(Continued)
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 tap on the brake pedal, pushing the CANC
(cancel) button, or normal brake pressure while
slowing the vehicle will deactivate the Cruise
Control system without erasing the set speed
from memory.
The following conditions will also deactivate the
Cruise Control system 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
Pushing the on/off button or placing the ignition
in the OFF position, erases the set speed from
memory.
ADAPTIVE CRUISE CONTROL (ACC) — IF
E
QUIPPED
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. The
Cruise Control function performs differently
Ú page 177.
ACC will allow you to keep Cruise Control
engaged in light to moderate traffic conditions
without the constant need to reset your speed.
ACC utilizes a radar sensor and a forward facing
camera designed to detect a vehicle directly
ahead of you to maintain a set speed.
NOTE:
If the ACC sensor detects a vehicle ahead,
ACC will apply limited braking or acceleration
(not to exceed the original set speed) auto -
matically to maintain a preset following
distance, while matching the speed of the
vehicle ahead.
Any chassis/suspension or tire size modifica -
tions to the vehicle will affect the perfor -
mance of the Adaptive Cruise Control and
Forward Collision Warning system.
Fixed Speed Cruise Control alone (an ACC
distance not set) will not detect vehicles
directly ahead of you. Always be aware of the
mode 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.
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184STARTING AND OPERATING
When An ACC Distance Is Also Set:
When you use the SET (-) button to decel -
erate, if the engine’s braking power does not
slow the vehicle sufficiently to reach the set
speed, the brake system will automatically
slow the vehicle.
The ACC system decelerates the vehicle to a
full stop when following the vehicle in front. If
your vehicle follows the vehicle in front to a
standstill, after two seconds the driver will
either have to push the RES (resume) button,
or apply the accelerator pedal to reengage
the ACC to the existing set speed.
The ACC system maintains set speed when
driving uphill and downhill. However, a slight
speed change on moderate hills is normal. In
addition, downshifting may occur while
climbing uphill or descending downhill. This
is normal operation and necessary to main -
tain set speed. When driving uphill and down -
hill, the ACC system will cancel if the braking
temperature exceeds normal range (over -
heated).
Setting The Following Distance In ACC
The specified following distance for Adaptive
Cruise Control (ACC) can be set by varying the
distance setting between four bars (longest),
three bars (long), two bars (medium) and one
bar (short). Using this distance setting and the
vehicle speed, ACC calculates and sets the
distance to the vehicle ahead. This distance
setting displays in the instrument cluster
display.

Distance Settings
To increase the distance setting, push the
Distance Increase button and release. Each
time the button is pushed, the distance setting
increases by one bar (longer).
To decrease the distance setting, push the
Distance Decrease button and release. Each
time the button is pushed, the distance setting
decreases by one bar (shorter).
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 Detected 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.
1 — Longest Distance Setting (Four Bars)
2 — Long Distance Setting (Three Bars)
3 — Medium Distance Setting (Two Bars)
4 — Short Distance Setting (One Bar)

21_DT_OM_EN_USC_t.book Page 184

208STARTING AND OPERATING
AUX CAMERA — IF EQUIPPED
Your vehicle may be equipped with one or two
AUX Cameras, which display images from the
trailer on the touchscreen.
Activation
The AUX Camera is activated any of the
following ways:
By first pressing the Backup Camera or
Surround View Camera (if equipped) button
on the touchscreen, followed by the AUX
button located in the upper left corner of the
rearview display
Pressing the AUX button in the Apps menu
Pressing the AUX button when the vehicle is
in REVERSE
If equipped with two AUX Cameras, you can
switch between each camera by pressing the
AUX1 or AUX2 buttons on the Trailer Camera
display. AUX1 Camera Button
AUX2 Camera Button
Deactivation
The AUX Camera is deactivated when the
following situations occur:
The “X” in the upper right corner of the touch -
screen is pressed. This will return the display
back to the previously displayed screen.
The vehicle speed exceeds 8 mph (13 km/h)
for 10 seconds.
The vehicle is shifted into PARK.
The ignition is placed in the OFF position. NOTE:
If the AUX button is pressed and no AUX
Camera is connected, the touchscreen will
display a blue screen along with the message
“Camera System Unavailable.” The screen
can be exited out by pressing the “X” in the
upper right hand corner. This will return the
display back to the previously displayed
screen.
Zoom View is not available with the AUX
Camera feature.
The display will always default to the Trailer
Camera display (AUX 1).
REFUELING THE VEHICLE — GASOLINE
ENGINE
The capless fuel filler is located on the left side
of the vehicle.
The capless system is sealed by two flapper
doors.
CAUTION!
To avoid vehicle damage, Surround View
should only be used as a parking aid. The
Surround View camera is unable to view
every obstacle or object in your drive path.
To avoid vehicle damage, the vehicle must
be driven slowly when using Surround View
to be able to stop in time when an obstacle
is seen. It is recommended that the driver
look frequently over his/her shoulder when
using Surround View.

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STARTING AND OPERATING209

1. Put the vehicle in PARK and switch the
ignition off.

2. Push the center-rear edge of the fuel filler door (3 o'clock position) and release to
open.
Fuel Filler Door

3. Insert the fuel nozzle fully into the filler pipe, the nozzle opens and holds both flapper
doors while refueling.

Fuel Filler

4. When the fuel nozzle “clicks” or shuts off, the fuel tank is full. 5. Keep the nozzle in the filler for five seconds
after nozzle clicks to allow fuel to drain from
the nozzle.
6. Remove the fuel filler nozzle.
7. To close the fuel filler door, push the center-rear edge (3 o’clock position) of the
fuel filler door and then release. The fuel
filler door will latch closed.
NOTE:
In certain cold conditions, ice may prevent the
fuel filler door from opening. If this occurs,
lightly push on the fuel filler door around the
perimeter to break the ice build up.
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 MIL to
turn on.
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!
To avoid fuel spillage and overfilling, do not
“top off” the fuel tank after filling.
WARNING!
Always place container on the ground
before filling.
Keep the pump nozzle in contact with the
container when you are filling it.
Use only approved containers for flam -
mable liquid.
Do not leave container unattended while
filling.
A static electric charge could cause a spark
and fire hazard.
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210STARTING AND OPERATING
REFUELING THE VEHICLE — DIESEL ENGINE
The capless fuel filler is located on the left side
of the vehicle.
The capless system is sealed by two flapper
doors.

1. Put the vehicle in PARK and switch the
ignition off.

2. Open the fuel filler door.

Diesel Fuel And Diesel Exhaust Fluid Fill Location

3. Insert the fuel nozzle fully into the filler pipe – the nozzle opens and holds the flapper
door while refueling. 4. Fill the vehicle with fuel – when the fuel
nozzle “clicks” or shuts off, the fuel tank is
full.
5. Remove the fuel nozzle and close the fuel door.
AVOID USING CONTAMINATED FUEL
Fuel that is contaminated by water or dirt can
cause severe damage to the engine fuel
system. Proper maintenance of the engine fuel
filter and fuel tank is essential Ú page 409.
BULK FUEL STORAGE — DIESEL FUEL
If you store quantities of fuel, good
maintenance of the stored fuel is also essential.
Fuel contaminated with water will promote the
growth of “microbes.” These microbes form
“slime” that will clog the fuel filtration system
and lines. Drain condensation from the supply
tank and change the line filter on a regular
basis.
NOTE:
When a diesel engine is allowed to run out of
fuel, air is pulled into the fuel system.
If the vehicle will not start Úpage 414.
1 — Diesel Exhaust Fluid (DEF) Fill Location
2 — 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!
Do not open the high pressure fuel system
with the engine running. Engine operation
causes high fuel pressure. High pressure fuel
spray can cause serious injury or death.

21_DT_OM_EN_USC_t.book Page 210

STARTING AND OPERATING211
DIESEL EXHAUST FLUID
Your vehicle is equipped with a Selective
Catalytic Reduction (SCR) system to meet diesel
emissions standards required by the
Environmental Protection Agency.
The purpose of the SCR system is to reduce
levels of oxides of nitrogen (NO
x) 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, converts smog-forming
NO
x into harmless nitrogen (N2) and water
vapor (H
2O), two natural components of the air
we breathe.
DIESEL EXHAUST FLUID STORAGE
Diesel Exhaust Fluid (DEF) is considered a very
stable product with a long shelf life. If DEF is
kept in temperatures between 10° and 90°F
(-12° and 32°C), it will last a minimum of one
year.
DEF may freeze at temperatures at or below
12°F (-11°C). The system has been designed to
operate in this environment. NOTE:
When working with DEF, it is important to know
that:
Any containers or parts that come into
contact with DEF must be DEF compatible
(plastic or stainless steel). Copper, brass,
aluminum, iron or non-stainless steel should
be avoided as they are subject to corrosion
by DEF.
If DEF is spilled, it should be wiped up
completely.
ADDING DIESEL EXHAUST FLUID
The Diesel Exhaust Fluid (DEF) gauge (located
on the instrument cluster) will display the level
of DEF remaining in the tank Ú
page 109.
NOTE:
Driving conditions (altitude, vehicle speed,
load, etc.) will effect the amount of DEF that
is used in your vehicle.
Outside temperature can affect DEF
consumption. In cold conditions, 12°F
(-11°C) and below, the DEF gauge may take
longer to operate as intended. This is a
normal function of the system.
There is an electric heater inside the DEF
tank that automatically works when neces -
sary. And if the DEF supply does freeze, the
truck will operate normally until it thaws.
Diesel Exhaust Fluid (DEF) Fill Procedure
NOTE:
For the correct fluid type Ú page 475.

1. Remove cap from Diesel Exhaust Fluid (DEF) tank which is located next to the
diesel fuel filler.

DEF Filler Cap And Fuel Fill

1 — Diesel Exhaust Fluid (DEF) Fill Location
2 — Diesel Fuel Fill Location
4

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