2021 RAM CHASSIS CAB tires

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

208STARTING AND OPERATING
If a fault is detected in the trailer wiring or the
Integrated Trailer Brake Module (ITBM), the
“Trailer Brake Status Indicator Light” will flash.
GAIN Adjustment Buttons (+/-)
Pushing these buttons will adjust the brake
control power output to the trailer brakes in
0.5 increments. The GAIN setting can be
increased to a maximum of 10 or decreased
to a minimum of 0 (no trailer braking).
GAIN
The GAIN setting is used to set the trailer brake
control for the specific towing condition and
should be changed as towing conditions
change. Changes to towing conditions include
trailer load, vehicle load, road conditions and
weather.
Adjusting GAIN
NOTE:
This should only be performed in a traffic-free
environment at speeds of approximately
20–25 mph (30–40 km/h).
1. Make sure the trailer brakes are in good
working condition, functioning normally
and properly adjusted. See a trailer dealer
if necessary.

2. Hook up the trailer and make the electrical connections according to the trailer
manufacturer's instructions.
3. When a trailer with electric/EOH brakes is plugged in, the trailer connected message
should appear in the instrument cluster
display (if the connection is not recognized
by the ITBM, braking functions will not be
available), the GAIN setting will illuminate
and the correct type of trailer must be
selected from the instrument cluster display
options.
4. Push the UP or DOWN button on the steering wheel until “TRAILER TOW”
appears on the screen.
5. Push the RIGHT arrow on the steering wheel to enter “TRAILER TOW”. 6. Push the UP or DOWN buttons until the
Trailer Brake Type appears on the screen.
7. Push the RIGHT arrow and then push the UP or DOWN buttons until the proper Trailer
Brake Type appears on the screen.
8. In a traffic-free environment, tow the trailer on a dry, level surface at a speed of
20–25 mph (30–40 km/h) and squeeze
the manual brake control lever completely.
9. If the trailer wheels lockup (indicated by squealing tires), reduce the GAIN setting; if
the trailer wheels turn freely, increase the
GAIN setting.
Repeat steps 8 and 9 until the GAIN setting is at
a point just below trailer wheel lockup. If towing
a heavier trailer, trailer wheel lockup may not be
attainable even with the maximum GAIN setting
of 10.

21_DPF_OM_EN_USC_t.book Page 208

273
(Continued)
SAFETY
SAFETY FEATURES
ANTI-LOCK BRAKE SYSTEM (ABS)
The ABS provides increased vehicle stability
and brake performance under most braking
conditions. The system automatically prevents
wheel lock, and enhances vehicle control during
braking.

The ABS performs a self-check cycle to ensure
that the ABS is working properly each time the
vehicle is started and driven. During this
self-check, you may hear a slight clicking sound
as well as some related motor noises.

ABS is activated during braking when the
system detects one or more wheels are
beginning to lock. Road conditions such as ice,
snow, gravel, bumps, railroad tracks, loose
debris, or panic stops may increase the
likelihood of ABS activation(s).You also may experience the following normal
characteristics when ABS activates:
The ABS motor noise or clicking sounds (you
may continue to hear for a short time after
the stop)
Brake pedal pulsations
A slight drop of the brake pedal at the end of
the stop

ABS is designed to function with the Original
Equipment Manufacturer (OEM) tires. Modification
may result in degraded ABS performance.

WARNING!
The ABS contains sophisticated electronic
equipment that may be susceptible to inter -
ference caused by improperly installed or
high output radio transmitting equipment.
This interference can cause possible loss of
anti-lock braking capability. Installation of
such equipment should be performed by
qualified professionals.

Pumping of the Anti-Lock Brakes will diminish
their effectiveness and may lead to a collision.
Pumping makes the stopping distance longer.
Just press firmly on your brake pedal when you
need to slow down or stop.

The ABS cannot prevent the natural laws of
physics from acting on the vehicle, nor can
it increase braking or steering efficiency
beyond that afforded by the condition of the
vehicle brakes and tires or the traction
afforded.
The ABS cannot prevent collisions,
including those resulting from excessive
speed in turns, following another vehicle
too closely, or hydroplaning.
The capabilities of an ABS equipped vehicle
must never be exploited in a reckless or
dangerous manner that could jeopardize
the user’s safety or the safety of others.
WARNING! (Continued)
6

21_DPF_OM_EN_USC_t.book Page 273

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

278SAFETY

The ESC Activation/Malfunction Indicator Light
starts to flash as soon as the tires lose traction
and the ESC system becomes active. The ESC
Activation/Malfunction Indicator Light also
flashes when TCS is active. If the ESC Activation/
Malfunction Indicator Light begins to flash during
acceleration, ease up on the accelerator and
apply as little throttle as possible. Be sure to
adapt your speed and driving to the prevailing
road conditions.

The ESC OFF Indicator Light indicates
that the Electronic Stability Control
(ESC) is in a reduced mode.
NOTE:
The ESC Activation/Malfunction Indicator
Light and the ESC OFF Indicator Light come
on momentarily each time the ignition is
placed in the ON position.
Each time the ignition is placed in the ON
position, the ESC system will be on even if it
was turned off previously.
The ESC system will make buzzing or clicking
sounds when it is active. This is normal; the
sounds will stop when ESC becomes inactive
following the maneuver that caused the ESC
activation.
Hill Descent Control (HDC) — If Equipped
HDC is intended for low speed off-road driving
while in 4WD Low. HDC maintains vehicle speed
while descending hills during various driving
situations. HDC controls vehicle speed by
actively controlling the brakes.
HDC Has Three States:

1. Off (feature is not enabled and will not activate).

2. Enabled (feature is enabled and ready but activation conditions are not met, or driver
is actively overriding with brake or throttle
application).
3. Active (feature is enabled and actively controlling vehicle speed).
Enabling HDC
HDC is enabled by pushing the HDC switch, but
the following conditions must also be met to
enable HDC:
The driveline is in 4WD Low.
The vehicle speed is below 5 mph (8 km/h).
The parking brake is released.
The driver door is closed. Activating HDC
Once HDC is enabled it will activate
automatically if driven down a grade of
sufficient magnitude. The set speed for HDC is
selectable by the driver, and can be adjusted by
using the gear shift +/-. The following
summarizes the HDC set speeds:
HDC Target Set Speeds
P = No set speed. HDC may be enabled but
will not activate.
R = 0.6 mph (1 km/h)
N = 1.2 mph (2 km/h)
D = 0.6 mph (1 km/h)
1st = 0.6 mph (1 km/h)
2nd = 1.2 mph (2 km/h)
3rd = 1.8 mph (3 km/h)
4th = 2.5 mph (4 km/h)
5th = 3.1 mph (5 km/h)
6th = 3.7 mph (6 km/h)
7th = 4.3 mph (7 km/h)

21_DPF_OM_EN_USC_t.book Page 278

284SAFETY
TIRE PRESSURE MONITORING
S
YSTEM (TPMS)
(Vehicles Under 10K Gross Vehicle Weight
Rating (GVWR) Only)
The Tire Pressure Monitoring System (TPMS)
will warn the driver of a low tire pressure based
on the vehicle recommended cold placard
pressure.
NOTE:
The TPMS Warning Light will illuminate in the
instrument cluster and a chime will sound when
tire pressure is low in one or more of the four
active road tires. In addition, the instrument
cluster will display a graphic showing the pres -
sure values of each tire with the low tire pres -
sure values in a different color, or the Uconnect
radio will display a TPMS message. When this
occurs you must increase the tire pressure to
the recommended cold placard pressure in
order for the TPMS Warning Light to turn off.
The tire pressure will vary with temperature
by about 1 psi (7 kPa) for every 12°F (6.5°C).
This means that when the outside temperature
decreases, the tire pressure will decrease.
Tire pressure should always be set based on
cold inflation tire pressure. This is defined as the tire pressure after the vehicle has not been
driven for at least three hours, or driven less
than 1 mile (1.6 km) after a three hour period.
The cold tire inflation pressure must not exceed
the maximum inflation pressure molded into
the tire sidewall. The tire pressure will also
increase as the vehicle is driven — this is normal
and there should be no adjustment for this
increased pressure.
See
Úpage 406 on how to properly inflate the
vehicle’s tires.
The TPMS will warn the driver of a low tire
pressure if the tire pressure falls below the
low-pressure warning limit for any reason,
including low temperature effects and natural
pressure loss through the tire.
The TPMS will continue to warn the driver of low
tire pressure as long as the condition exists,
and will not turn off until the tire pressure is
at or above the recommended cold placard
pressure. Once the low TPMS Warning Light
illuminates, you must increase the tire pressure
to the recommended cold placard pressure in
order for the TPMS Warning Light to turn off.
The system will automatically update and the
TPMS Warning Light will turn off once the
system receives the updated tire pressures. The vehicle may need to be driven for up to
20 minutes above 15 mph (24 km/h) in order
for the TPMS to receive this information.
NOTE:
When filling warm tires, the tire pressure may
need to be increased up to an additional 4 psi
(28 kPa) above the recommended cold placard
pressure in order to turn the TPMS Warning
Light off.

For example, your vehicle may have a
recommended cold (parked for more than
three hours) placard pressure of 30 psi
(207 kPa). If the ambient temperature is 68°F
(20°C) and the measured tire pressure is 27 psi
(186 kPa), a temperature drop to 20°F (-7°C) will
decrease the tire pressure to approximately
23 psi (158 kPa). This tire pressure is sufficiently
low enough to turn on the TPMS Warning Light.
Driving the vehicle may cause the tire pressure to
rise to approximately 27 psi (186 kPa), but the
TPMS Warning Light will still be on. In this
situation, the TPMS Warning Light will turn off
only after the tires are inflated to the vehicle’s
recommended cold placard pressure value

Ú

page 449.

21_DPF_OM_EN_USC_t.book Page 284

SAFETY285
NOTE:
The TPMS is not intended to replace normal
tire care and maintenance or to provide
warning of a tire failure or condition.
If your vehicle is not equipped with the Tire
Fill Alert feature the TPMS should not be used
as a tire pressure gauge while adjusting your
tire pressure.
Driving on a significantly underinflated tire
causes the tire to overheat and can lead to
tire failure. Underinflation also reduces fuel
efficiency and tire tread life, and may affect
the vehicle’s handling and stopping ability.

The TPMS is not a substitute for proper tire
maintenance, and it is the driver’s responsi -
bility to maintain correct tire pressure using an
accurate tire pressure gauge, even if underin-
flation has not reached the level to trigger illu -
mination of the TPMS Warning Light.

Seasonal temperature changes will affect
tire pressure, and the TPMS will monitor the
actual tire pressure in the tire.
Example: Tire Pressure Monitoring System Display

The Tire Pressure Monitoring System (TPMS)
uses wireless technology with wheel rim
mounted electronic sensors to monitor tire
pressure levels. Sensors, mounted to each
wheel as part of the valve stem, transmit tire
pressure readings to the receiver module.
NOTE:
It is particularly important for you to check the
tire pressure in all of the tires on your vehicle
monthly and to maintain the proper pressure.
CAUTION!
The TPMS has been optimized for the orig -
inal equipment tires and wheels. TPMS
pressures and warning have been estab -
lished for the tire size equipped on your
vehicle. Undesirable system operation or
sensor damage may result when using
replacement equipment that is not of the
same size, type, and/or style. Aftermarket
wheels can cause sensor damage.
Using aftermarket tire sealants may cause
the Tire Pressure Monitoring System
(TPMS) sensor to become inoperable.
After using an aftermarket tire sealant it is
recommended that you take your vehicle to
an authorized dealership to have your
sensor function checked.
After inspecting or adjusting the tire pres -
sure always reinstall the valve stem cap.
This will prevent moisture and dirt from
entering the valve stem, which could
damage the TPMS sensor.
6

21_DPF_OM_EN_USC_t.book Page 285