2021 RAM CHASSIS CAB cruise control

STARTING AND OPERATING171
To Vary The Speed Setting
To Increase Or Decrease The Set Speed
After setting a speed, you can increase the
set speed by pushing the RES (+) button, or
decrease speed by pushing the SET (-) button.
U.S. Speed (mph)
Pushing the RES (+) button, or SET (-) button
once will result in a 1 mph speed adjustment.
Each subsequent tap of the button results in
an adjustment of 1 mph.
If the button is continually pushed, the set
speed will continue to adjust in 5 mph incre -
ments until the button is released. The new
set speed is reflected in the instrument
cluster display.
Metric Speed (km/h)
Pushing the RES (+) button, or SET (-) button
once will result in a 1 km/h speed adjust -
ment. Each subsequent tap of the button
results in an adjustment of 1 km/h.
If the button is continually pushed, the set
speed will continue to adjust in 10 km/h
increments until the button is released.
The new set speed is reflected in the instru -
ment cluster display. 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 applies the brake down to a
full stop when following the vehicle in front.
If your vehicle follows the vehicle in front to
a standstill, your vehicle will release the
brakes two seconds after coming to a
complete stop.
 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

1 — Longest Distance Setting (Four Bars)
2 — Long Distance Setting (Three Bars)
3 — Medium Distance Setting (Two Bars)
4 — Short Distance Setting (One Bar)
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STARTING AND OPERATING173 If the vehicle in front does not start moving
within two seconds of your vehicle coming to a
standstill, the ACC with Stop system will
cancel and the brakes will release. A cancel
message will display on the instrument cluster
display and produce a warning chime. The
driver must now manually operate the
vehicle's accelerator and brakes.
While ACC is holding your vehicle at a
standstill, if the driver seat belt is unbuckled
or the driver door is opened, the ACC system
will cancel and the brakes will release. Driver
intervention will be required at this moment.
Display Warnings And Maintenance
“Wipe Front Radar Sensor In Front Of Vehicle”
Warning
The “ACC/FCW Unavailable Wipe Front Radar
Sensor” warning will display and a chime will
sound when conditions temporarily limit system
performance.
This most often occurs at times of poor visibility,
such as in snow or heavy rain. The ACC system
may also become temporarily blinded due to
obstructions, such as mud, dirt or ice. In these
cases, the instrument cluster display will display
“ACC/FCW Unavailable Wipe Front Radar
Sensor” and the system will deactivate.

This message can sometimes be displayed while
driving in highly reflective areas (i.e. ice and snow, or
tunnels with reflective tiles). The ACC system will
recover after the vehicle has left these areas. Under
rare conditions, when the radar is not tracking any
vehicles or objects in its path this warning may
temporarily occur.
NOTE:
If the “ACC/FCW Unavailable Wipe Front Radar
Sensor” warning is active, Fixed Speed Cruise
Control is still available.

If weather conditions are not a factor, the driver
should examine the sensor. It may require
cleaning or removal of an obstruction. The sensor
is located in the camera in the center of the
windshield, on the forward side of the rearview
mirror.

To keep the ACC system operating properly, it is
important to note the following maintenance
items:
Always keep the sensor clean. Carefully clear
the windshield.
Do not remove any screws from the sensor.
Doing so could cause an ACC system
malfunction or failure and require a sensor
realignment.
Do not attach or install any accessories near
the sensor, including transparent material or
aftermarket grilles. Doing so could cause an
ACC system failure or malfunction.
WARNING!

When the ACC system is resumed, the driver
must ensure that there are no pedestrians,
vehicles or objects in the path of the vehicle.
Failure to follow these warnings can result in a
collision and death or serious personal injury.

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174STARTING AND OPERATING
When the condition that deactivated the system
is no longer present, the system will return to
the “Adaptive Cruise Control Off” state and will
resume function by simply reactivating it.
NOTE:
If the “ACC/FCW Unavailable Wipe Front
Radar Sensor” message occurs frequently
(e.g. more than once on every trip) without
any snow, rain, mud, or other obstruction,
have the radar sensor realigned at an autho -
rized dealer.
Installing a snow plow, front-end protector,
an aftermarket grille or modifying the grille is
not recommended. Doing so may block the
sensor and inhibit ACC/FCW operation. “Clean Front Windshield” Warning
The “ACC/FCW Limited Functionality Clean
Front Windshield” warning will display and a
chime will sound when conditions temporarily
limit system performance. This most often
occurs at times of poor visibility, such as in
snow or heavy rain and fog. The ACC system
may also become temporarily blinded due to
obstructions, such as mud, dirt, or ice on
windshield, driving directly into the sun and fog
on the inside of glass. In these cases, the
instrument cluster display will show “ACC/FCW
Limited Functionality Clean Front Windshield”
and the system will have degraded
performance.
This message can sometimes be displayed
while driving in adverse weather conditions.
The ACC/FCW system will recover after the
vehicle has left these areas. Under rare
conditions, when the camera is not tracking
any vehicles or objects in its path this warning
may temporarily occur. If weather conditions are not a factor, the driver
should examine the windshield and the camera
located on the back side of the inside rearview
mirror. They may require cleaning or removal of
an obstruction.
When the condition that created limited
functionality is no longer present, the system
will return to full functionality.
NOTE:
If the “ACC/FCW Limited Functionality Clean
Front Windshield” message occurs frequently
(e.g. more than once on every trip) without any
snow, rain, mud, or other obstruction, have
the windshield and forward facing camera
inspected at an authorized dealer.

21_DPF_OM_EN_USC_t.book Page 174

STARTING AND OPERATING175
Service ACC/FCW Warning

If the system turns off, and the instrument cluster
displays “ACC/FCW Unavailable Service
Required” or “Cruise/FCW Unavailable Service
Required”, there may be an internal system fault
or a temporary malfunction that limits ACC
functionality. Although the vehicle is still drivable
under normal conditions, ACC will be temporarily
unavailable. If this occurs, try activating ACC
again later, following an ignition cycle. If the
problem persists, see an authorized dealer.

Precautions While Driving With ACC
NOTE:
Aftermarket add-ons such as snow plows, lift
kits, and brush/grille bars can hinder module
performance. Ensure the radar/camera has
no obstructions in the field of view.
Height modifications can limit module perfor -
mance and functionality.
Do not put stickers or easy passes over the
camera/radar field of view.
Any modifications to the vehicle that may
obstruct the field of view of the radar/camera
are not recommended.
In certain driving situations, ACC may have
detection issues. In these cases, ACC may
brake late or unexpectedly. The driver needs
to stay alert and may need to intervene.
The following are examples of these types of
situations:
Towing A Trailer
ACC while towing a trailer is recommended only
with an Integrated Trailer Brake Controller.
Aftermarket trailer brake controllers will not
activate the trailer brakes when ACC is braking. Offset Driving
ACC may not detect a vehicle in the same lane
that is offset from your direct line of travel, or a
vehicle merging in from a side lane. There may
not be sufficient distance to the vehicle ahead.
The offset vehicle may move in and out of the
line of travel, which can cause your vehicle to
brake or accelerate unexpectedly.

Offset Driving Condition Example

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212STARTING AND OPERATING
Tow/Haul Mode
To reduce potential for automatic transmission
overheating, activate TOW/HAUL mode when
driving in hilly areas, or select a lower gear
range (using the Electronic Range Select (ERS)
shift control) on more severe grades.
Cruise Control — If Equipped
Do not use on hilly terrain or with heavy
loads.
When using the Cruise Control, if you experi -
ence speed drops greater than 10 mph
(16 km/h), disengage until you can get back
to cruising speed.
Use Cruise Control in flat terrain and with
light loads to maximize fuel efficiency.
SNOWPLOW — IF EQUIPPED
Snowplow Prep Packages are available as a
factory installed option. These packages
include components necessary to equip your
vehicle with a snowplow. NOTE:
Before installation of a snowplow it is highly
recommended that the owner/installer obtain
and follow the recommendations contained
within the current Body Builders Guide. See an
authorized dealer, installer or snowplow manu
-
facturer for this information. There are unique
electrical systems that must be connected to
properly ensure operator safety and prevent
overloading vehicle systems.
BEFORE PLOWING
Check the hydraulic system for leaks and
proper fluid level.
Check the mounting bolts and nuts for proper
tightness.
Check the runners and cutting edge for
excessive wear. The cutting edge should be
¼ to ½ inches (6 cm to 1.2 cm) above ground
in snow plowing position.
Check that snowplow lighting is connected
and functioning properly.
SNOWPLOW PREP PACKAGE MODEL
A
VAILABILITY
For Information about snowplow applications
visit www.ramtrucks.com or refer to the current
Body Builders Guide.

1. The maximum number of occupants in the
truck should not exceed two.

2. The total GVWR or the Front GAWR or the Rear GAWR should never be exceeded.
3. Cargo capacity will be reduced by the addition of options or passengers, etc.
WARNING!
Attaching a snowplow to this vehicle could
adversely affect performance of the airbag
system in a collision. Do not expect that the
airbag will perform as described earlier in this
manual.
CAUTION!
The “Lamp Out” indicator could illuminate if
exterior lamps are not properly installed.

21_DPF_OM_EN_USC_t.book Page 212

SERVICING AND MAINTENANCE399
F74–10 Amp Red Backup Alarm – If Equipped
F75 –10 Amp Red ATMM / Coil-SCR Module RLY – If Equipped
F76 –10 Amp Red Electronic Stability Control — If Equipped
F77 –10 Amp Red Drivetrain Control Module / Front Axle Disconnect Module / TCM/ STOM
F78 –15 Amp BlueEngine Control Module / Powertrain Control Module / AEB RACM MOD /
Feed To AUX PDC Relay Coils/ HRLS
F79 –15 Amp Blue ID / Clearance Lights
F80 –10 Amp Red Overhead Console / Assist / 911 – If Equipped
F81 –20 Amp Yellow Trailer Tow Right Turn / Stop Lights - If Equipped
F82 –10 Amp Red Steering Column Control Module / Cruise Control
F83 – –Spare
F84 –15 Amp Blue ASBM / HVAC / ICS / Rear Heated Seat Switches
F85 –10 Amp Red Airbag Module
F86 –10 Amp Red Airbag Module
F87 –10 Amp RedAir Suspension / ITBM / Steering Column Control Module / MOD Gateway
CAN-C Trailer TPM
F88 –15 Amp Blue Instrument Panel Cluster
F90/F91 –20 Amp Yellow Power Outlet / Batt
Power Outlet / Acc
F92 – –Spare
F93 – –Spare
Cavity Cartridge Fuse Micro Fuse Description
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450
INDEX
 Pair (Link) Uconnect Phone To A Mobile
Phone............................................................ 260 WARRANTY INFORMATION...................... 447
A
Adaptive Cruise Control (ACC)
(Cruise Control)
.................................... 164, 166Adding Engine Coolant (Antifreeze)............... 384Adding Fuel.................................................... 196Additives, Fuel............................................... 434Adjust Down........................................................... 35Forward....................................................... 35Rearward..................................................... 35Up................................................................ 35Adjustable Pedals............................................ 40Advance Phone Connectivity......................... 266Air BagAir Bag Operation...................................... 305Air Bag Warning Light................................ 303Enhanced Accident Response......... 310, 352Event Data Recorder (EDR)....................... 352If Deployment Occurs................................ 309Knee Impact Bolsters................................ 305Maintaining Your Air Bag System.............. 311Maintenance............................................. 311
Redundant Air Bag Warning Light............. 303Transporting Pets..................................... 330Air Bag Light................................ 107, 303, 331Air Cleaner, Engine (Engine Air Cleaner
Filter)................................................... 369, 391Air Conditioner Maintenance........................ 371Air Conditioner Refrigerant.................. 371, 372Air Conditioner System................................. 371Air Conditioning................................................ 62Air Conditioning Filter....................................... 65Air Conditioning System................................... 64Air Conditioning, Operating Tips....................... 65Air Filter........................................................ 369Air PressureTires......................................................... 415AlarmSecurity Alarm....................................23, 108Alterations/ModificationsVehicle......................................................... 10Antifreeze (Engine Coolant).......................... 384Capacities................................................. 439Disposal................................................... 385Anti-Lock Brake System (ABS)...................... 273Anti-Lock Warning Light................................ 113Assist, Hill Start............................................. 280Audio Settings............................................... 253Audio Systems (Radio).................................. 220
Auto Down Power Windows..............................77Automatic Door Locks......................................28Automatic Headlights.......................................52Automatic Temperature Control (ATC)..............64Automatic Transmission....................... 141, 389Adding Fluid.............................................. 389Fluid And Filter Change............................. 389Fluid Change............................................. 389Fluid Level Check............................. 387, 388Fluid Type........................................ 390, 444Shifting..................................................... 146Special Additives...................................... 387Automatic Transmission Limp Home Mode... 145AutoPark....................................................... 120AUX Camera......................................... 188, 194Auxiliary Driving Systems.............................. 281Axle Fluid.....................................390, 391, 444Axle Lubrication................................... 390, 391
B
Back-Up......................................................... 186Back-Up Camera........................................... 186Battery................................................. 108, 366Blanket..................................................... 130Charging System Light.............................. 108Keyless Key Fob Replacement....................16Battery Saver Feature......................................54

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451
Belts, Seat
..................................................... 330Bluetooth Connecting To A Particular Mobile Phone Or Audio Device After Pairing
................262Body Builders Guide........................................ 10Body Mechanism Lubrication........................ 380B-Pillar Location............................................. 411Brake Assist System...................................... 274Brake Control System.................................... 274Brake Fluid.......................................... 387, 444Brake System...................................... 387, 431Fluid Check............................................... 387Master Cylinder......................................... 387Parking...................................................... 137Warning Light............................................ 107Brake/Transmission Interlock....................... 141Bulb Replacement......................................... 401Bulbs, Light.......................................... 332, 401
C
Cab Top Clearance Lights.............................. 405Camera.......................................................... 186Camera, AUX........................................ 188, 194Camera, Rear...................................... 186, 189Capacities, Antifreeze (Engine Coolant)......... 439Capacities, Fluid............................................ 439Caps, FillerOil (Engine)................................................ 364Power Steering.......................................... 163Radiator (Coolant Pressure)...................... 385
Car Washes................................................... 428Carbon Monoxide Warning............................ 333Cargo Light....................................................... 54CD................................................................. 255Cellular Phone.............................................. 269Center High Mounted Stop Light................... 405Center Seat Storage Compartment.................. 67Changing A Flat Tire...................................... 339Charge Air Cooler.......................................... 386Chart, Tire Sizing........................................... 407Check Engine Light (Malfunction
Indicator Light).............................................. 117Checking Your Vehicle For Safety................. 330Checks, Safety.............................................. 330Child Restraint.............................................. 312Child RestraintsBooster Seats........................................... 315Child Seat Installation..................... 323, 325How To Stow An unused ALR Seat Belt.... 322Infant And Child Restraints....................... 313Locating The LATCH Anchorages.............. 320Lower Anchors And Tethers For Children.. 317Older Children And Child Restraints......... 314Seating Positions...................................... 316Clean Air Gasoline......................................... 433CleaningWheels..................................................... 421Climate Control................................................ 58Automatic.................................................... 59Manual........................................................ 62
Cold Weather Operation................................ 122Compact Spare Tire...................................... 419Contract, Service........................................... 446Controls........................................................ 247Cooling Pressure Cap (Radiator Cap)............ 385Cooling System............................................. 383Adding Coolant (Antifreeze)...................... 384Coolant Level................................... 384, 386Cooling Capacity....................................... 439Disposal Of Used Coolant......................... 385Drain, Flush, And Refill............................. 384Inspection................................................. 386Points To Remember................................ 386Pressure Cap............................................ 385Radiator Cap............................................. 385Selection Of Coolant (Antifreeze)..... 384, 440Corrosion Protection..................................... 427Cruise Control (Speed Control)............. 164, 166Cruise Light................................................... 115Customer Assistance.................................... 445Cybersecurity................................................ 220
D
Daytime Running Lights...................................51Dealer Service............................................... 367Defroster, Rear Window...................................62Defroster, Windshield............................ 62, 331Delay (Intermittent) Wipers..............................57Deleting A Phone........................................... 262Diagnostic System, Onboard......................... 116
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