2021 RAM CHASSIS CAB suspension

166STARTING AND OPERATING
(Continued)
The following conditions will also deactivate the
Cruise 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
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 if your vehicle is not
equipped with ACC
Ú
page 164.
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 operation to ensure safe
operation of the vehicle under all road condi -
tions. 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).
Cannot take street, traffic, and weather
conditions into account, and may be
limited upon adverse sight distance
conditions.

21_DPF_OM_EN_USC_t.book Page 166

200STARTING AND OPERATING
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
components in the system with the lowest load
carrying capacity (axle, springs, tires or wheels).
Heavier axles or suspension components
sometimes 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 conditions, 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
specified 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.
TRAILER TOWING
In this section you will find safety tips and
information on limits to the type of towing you
can reasonably do with your vehicle. Before
towing a trailer, carefully review this information
to tow your load as efficiently and safely as
possible.
To maintain the New Vehicle Limited Warranty
coverage, follow the requirements and
recommendations in this manual concerning
vehicles used for trailer towing.
CAUTION!

Do not load your vehicle any heavier than the
GVWR or the maximum front and rear GAWR. If
you do, parts on your vehicle can break, or it
can change the way your vehicle handles.
This could cause you to lose control. Also
overloading can shorten the life of your vehicle.

21_DPF_OM_EN_USC_t.book Page 200

206STARTING AND OPERATING
(Continued)
Towing Requirements — Tires
Do not attempt to tow a trailer while using a
compact spare tire.
Do not drive more than 50 mph (80 km/h) when towing while using a full size spare tire.
Proper tire inflation pressures are essential
to the safe and satisfactory operation of your
vehicle.
Check the trailer tires for proper tire inflation
pressures before trailer usage.
Check for signs of tire wear or visible tire
damage before towing a trailer.
For the proper tire replacement procedures.
Replacing tires with a higher load carrying
capacity will not increase the vehicle's GVWR
and GAWR limits.
For further information Ú page 406.
Towing Requirements — Trailer Brakes
Do not interconnect the hydraulic brake
system or vacuum system of your vehicle
with that of the trailer. This could cause inad -
equate braking and possible personal injury.
An electronically actuated trailer brake
controller is required when towing a trailer
with electronically actuated brakes. When
towing a trailer equipped with a hydraulic
surge actuated brake system, an electronic
brake controller is not required.
Trailer brakes are recommended for trailers
over 1,000 lbs (453 kg) and required for
trailers in excess of 2,000 lbs (907 kg).
WARNING!

Make certain that the load is secured in the
trailer and will not shift during travel. When
trailering cargo that is not fully secured,
dynamic load shifts can occur that may be diffi -
cult for the driver to control. You could lose
control of your vehicle and have a collision.

When hauling cargo or towing a trailer, do
not overload your vehicle or trailer. Over -
loading can cause a loss of control, poor
performance or damage to brakes, axle,
engine, transmission, steering, suspension,
chassis structure or tires.
Safety chains must always be used
between your vehicle and trailer. Always
connect the chains to the hook retainers of
the vehicle hitch. Cross the chains under
the trailer tongue and allow enough slack
for turning corners.
Vehicles with trailers should not be parked
on a grade. When parking, apply the
parking brake on the tow vehicle. Put the
tow vehicle transmission in PARK. For
four-wheel drive vehicles, make sure the
transfer case is not in NEUTRAL. Always,
block or "chock" the trailer wheels.
GCWR must not be exceeded.
Total weight must be distributed between
the tow vehicle and the trailer such that the
following four ratings are not exceeded :
GVWR
GTW
GAWR
Tongue weight rating for the trailer
hitch utilized.
WARNING! (Continued)

21_DPF_OM_EN_USC_t.book Page 206

MULTIMEDIA239
Key Off Options/Engine Off Options
When the Key Off Options/Engine Off Options button is pressed on the touchscreen, the system displays the options related to vehicle shutoff. These
settings will only activate when the ignition is set to OFF.
Suspension/Air Suspension
When the Suspension/Air Suspension button is pressed on the touchscreen, the system will display settings related to the vehicle’s air suspension.
Setting Name Description
Easy Exit SeatThis setting adjusts the seats to make exiting the vehicle easier.
Key Off/Engine Off Power Delay This setting will keep certain electrical features running after the engine is turned off.
When any door is opened, the electronics will deactivate. The available settings are “0 sec”,
“45 sec”, “5 min”, and “10 min”.
Headlight Off Delay This setting will allow you to set the amount of time the headlights remain on after the vehicle
has been turned off. The “+” will increase the amount of time. The “-” will decrease the
amount of time.
Auto Entry/Exit This setting will automatically lower the vehicle ride height for easier entry and exit of the
vehicle.
Setting Name
Description
Sound Horn With LowerThis setting will sound the horn when the Lower button is pressed on the key fob.
Flash Lights With Lower This setting will flash the lights when the Lower button is pressed on the key fob.
Display Suspension Messages This setting will display suspension messages in the Instrument Cluster Display. The “All”
setting will display all available messages. The “Warnings Only” setting will only display
warning messages.
5

21_DPF_OM_EN_USC_t.book Page 239

240MULTIMEDIA
AUX Switches — If Equipped
When the AUX Switches button is pressed on the touchscreen, the system displays the options related to the four vehicle AUX switches.Aero Mode
This setting will automatically adjust the vehicle ride height depending on the vehicle speed.
Tire Jack Mode This setting will disable the air suspension system to assist in changing a spare tire.
Transport Mode This setting will disable the air suspension system for flat towing.
Wheel Alignment Mode This setting must be activated before performing a wheel alignment. Refer to an authorized
dealer for further information.
Four Corner Air Suspension Modes There are three air suspension modes designed to protect the system in unique situations.
Tire Jack Mode is selected to assist in changing a spare tire. Transport Mode is selected to
assist when the vehicle is being flat bed towed. Wheel Alignment Mode is selected before
performing a wheel alignment. Refer to an authorized dealer for information.
Setting Name
Description
Setting NameDescription
AUX 1-4This setting will adjust the type and power source for the four vehicle AUX switches. There are
two types: “Latching” and “Momentary”. The power source for the AUX switches can either be
set to run off the “Battery” or from the “Ignition”. In addition to setting the type and power
source, you can set if the vehicle will recall the previous state at which the AUX switches were
set. The Recalled Last State setting can be set to “On” or “Off”. Last state conditions are met
only if the type is set to Latching and the power source is set to Ignition.

21_DPF_OM_EN_USC_t.book Page 240

276SAFETY
(Continued)
ESC Operating Modes

Depending upon model and mode of operation, the
ESC system may have multiple operating modes.

ESC On

This is the normal operating mode for the ESC
system. Whenever the vehicle is started, the ESC
system will be in this mode. This mode should be
used for most driving conditions. Alternate ESC
modes should only be used for specific reasons
as noted in the following paragraphs.

Partial Off
This mode may be useful if the vehicle becomes
stuck. This mode may modify TCS and ESC
thresholds for activation, which allows for more
wheel spin than normally allowed.
To enter the “Partial Off” mode, momentarily
push the ESC OFF button and the ESC OFF
Indicator Light will illuminate. To turn the ESC
on again, momentarily push the ESC OFF button
and the ESC OFF Indicator Light will turn off.WARNING!

Electronic Stability Control (ESC) cannot
prevent the natural laws of physics from acting
on the vehicle, nor can it increase the traction
afforded by prevailing road conditions. ESC
cannot prevent accidents, including those
resulting from excessive speed in turns, driving
on very slippery surfaces, or hydroplaning. ESC
also cannot prevent accidents resulting from
loss of vehicle control due to inappropriate
driver input for the conditions. Only a safe,
attentive, and skillful driver can prevent acci -
dents. The capabilities of an ESC equipped
vehicle must never be exploited in a reckless or
dangerous manner which could jeopardize the
user’s safety or the safety of others.Vehicle modifications, or failure to properly
maintain your vehicle, may change the
handling characteristics of your vehicle, and
may negatively affect the performance of the
ESC system. Changes to the steering system,
suspension, braking system, tire type and size
or wheel size may adversely affect ESC perfor -
mance. Improperly inflated and unevenly worn
tires may also degrade ESC performance.
Any vehicle modification or poor vehicle main -
tenance that reduces the effectiveness of the
ESC system can increase the risk of loss of
vehicle control, vehicle rollover, personal injury
and death.

WARNING! (Continued)

21_DPF_OM_EN_USC_t.book Page 276

SERVICING AND MAINTENANCE355
Mileage or time passed (whichever comes first)
20,000
30,000
40,000
50,000
60,000
70,000
80,000
90,000
100,000
110,000
120,000
130,000
140,000
150,000
Or Years: 2 3 4 5 6 7 8 9 10 11 12 13 14 15
Or Kilometers:
32,000
48,000
64,000
80,000
96,000
112,000
128,000
144,000
160,000
176,000
192,000
208,000
224,000
240,000
Additional Inspections
Inspect the CV/Universal joints. X X X X X X X X X X X X X X
Inspect front suspension, tie rod ends, and replace if necessary. X X X X X X X
Inspect the front and rear axle surfaces. If gear oil leakage is
suspected, check the fluid level. If using your vehicle for police,
taxi, fleet, off-road or frequent trailer towing, change axle fluid. X X X X X X X
Inspect the brake linings, parking brake function. X X X X X X X
Additional Maintenance
Replace the cabin air filter. X X X X X X X
Replace the engine air cleaner filter. XXXXX
Replace spark plugs.
1X
Flush and replace the engine coolant at 10 years or
150,000 miles (240,000 km) whichever comes first. X
X

Change the automatic transmission fluid (AS66RC Transmission Only).
XXX
8

21_DPF_OM_EN_USC_t.book Page 355

360SERVICING AND MAINTENANCE
Inspect engine air cleaner
filter, replace if necessary. 2X X X X X X X X X X
Inspect the front suspension,
tie rod ends and boot seals for
cracks or leaks and all parts
for damage, wear, improper
looseness or end play; replace
if necessary. X X X X X X X X X
X
Inspect the brake linings. XXXXX X
Inspect and adjust parking
brake. X
XXXX X
Inspect drive belt; replace as
necessary. X
XXXX X
Inspect wheel bearings. XXXX X
Additional Maintenance
Replace the cabin air filter. XXXXX X
Mileage or time passed
(whichever comes first):
7,500
15,000
22,500
30,000
37,500
45,000
52,500
60,000
67,500
75,000
82,500
90,000
97,500
105,000
112,500
120,000
127,500
135,000
142,500
150,000
Or Months: 6 12 18 24 30 36 42 48 54 60 66 72 78 84 90 96 102 108 114
120

Or Kilometers:
12,000
24,000
36,000
48,000
60,000
72,000
84,000
96,000
108,000
120,000
132,000
144,000
156,000
168,000
180,000
192,000
204,000
216,000
228,000
240,000

21_DPF_OM_EN_USC_t.book Page 360