2021 RAM CHASSIS CAB wheel size

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

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

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

SAFETY287

value will display in place of the dashes. A system
fault can occur due to any of the following:

Signal interference due to electronic devices
or driving next to facilities emitting the same
radio frequencies as the TPMS sensors.
Installing aftermarket window tinting that
contains materials that may block radio wave
signals.
Accumulation of snow or ice around the
wheels or wheel housings.
Using tire chains on the vehicle.
Using wheels/tires not equipped with TPMS
sensors.

A system fault may occur due to an incorrect
TPMS sensor location condition. When a system
fault occurs due to an incorrect TPMS sensor
location, the Tire Pressure Monitoring System
Warning Light will flash on and off for 75 seconds
and then remain on solid. The system fault will
also sound a chime. In addition, the instrument
cluster will display a “Tire Pressure Temporarily
Unavailable” message in place of the tire
pressure display screen. If the ignition switch is
cycled, this sequence will repeat, providing the
system fault still exists. If the system fault no longer exists, the Tire Pressure Monitoring
System Indicator Light will no longer flash and the
tire pressure display screen will be displayed
showing the tire pressure values in the correct
locations.

Vehicles With Non-Matching Full Size Spare Or
Compact Spare
The non-matching full size spare or compact
spare tire does not have a TPMS sensor.
Therefore, the TPMS will not monitor the
pressure in the non-matching full size spare
or compact spare tire.
If you install the non-matching full size spare
or compact spare tire in place of a road tire
that has a pressure below the low-pressure
warning limit, upon the next ignition switch
cycle, the TPMS Warning Light and a “LOW
TIRE” message will remain on and a chime
will sound. In addition, the graphic in the
instrument cluster will still display a pressure
value in a different color and an “Inflate to
XX” message.
After driving the vehicle for up to 20 minutes
above 15 mph (24 km/h), the TPMS Warning
Light will flash on and off for 75 seconds and
then remain on solid. In addition, the instru -ment cluster will display a "SERVICE TPM
SYSTEM" message for a minimum of
five seconds and then display dashes (- -) in
place of the pressure value.

For each subsequent ignition switch cycle, a
chime will sound, the TPMS Warning Light will
flash on and off for 75 seconds and then
remain on solid, and the instrument cluster will
display a "SERVICE TPM SYSTEM" message for
a minimum of five seconds and then display
dashes (- -) in place of the pressure value.

Once you repair or replace the original road
tire and reinstall it on the vehicle in place of
the non matching full size spare or compact
spare, the TPMS will update automatically.
In addition, the TPMS Warning Light will turn
off and the graphic in the instrument cluster
will display a new pressure value instead of
dashes (- -), as long as no tire pressure is
below the low-pressure warning limit in any of
the four active road tires. 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.
6

21_DPF_OM_EN_USC_t.book Page 287

SAFETY305
Front Air Bag Operation

Front Air Bags are designed to provide additional
protection by supplementing the seat belts. Front
air bags are not expected to reduce the risk of
injury in rear, side, or rollover collisions. The front
air bags will not deploy in all frontal collisions,
including some that may produce substantial
vehicle damage — for example, some pole
collisions, truck underrides, and angle offset
collisions.

On the other hand, depending on the type and
location of impact, front air bags may deploy in
crashes with little vehicle front-end damage but
that produce a severe initial deceleration.
Because air bag sensors measure vehicle
deceleration over time, vehicle speed and
damage by themselves are not good indicators
of whether or not an air bag should have
deployed.
Seat belts are necessary for your protection in
all collisions, and also are needed to help keep
you in position, away from an inflating air bag.
When the Occupant Restraint Controller (ORC)
detects a collision requiring the front air bags, it
signals the inflator units. A large quantity of
non-toxic gas is generated to inflate the front air
bags.

The steering wheel hub trim cover and the
upper passenger side of the instrument panel
separate and fold out of the way as the air bags
inflate to their full size. The front air bags fully
inflate in less time than it takes to blink your
eyes. The front air bags then quickly deflate
while helping to restrain the driver and front
passenger.
Knee Impact Bolsters
The Knee Impact Bolsters help protect the
knees of the driver and front passenger, and
position the front occupants for improved
interaction with the front air bags.
WARNING!
No objects should be placed over or near
the air bag on the instrument panel or
steering wheel because any such objects
could cause harm if the vehicle is in a colli
-
sion severe enough to cause the air bag to
inflate.

Do not put anything on or around the air bag
covers or attempt to open them manually.
You may damage the air bags and you could
be injured because the air bags may no
longer be functional. The protective covers
for the air bag cushions are designed to open
only when the air bags are inflating.

Relying on the air bags alone could lead to
more severe injuries in a collision. The air
bags work with your seat belt to restrain you
properly. In some collisions, air bags won’t
deploy at all. Always wear your seat belts
even though you have air bags.
WARNING!
Do not drill, cut, or tamper with the knee
impact bolsters in any way.
Do not mount any accessories to the knee
impact bolsters such as alarm lights,
stereos, citizen band radios, etc.
6

21_DPF_OM_EN_USC_t.book Page 305

SERVICING AND MAINTENANCE403
4. Reach through the access hole of the wheel
house splash shield and disengage the bulb
access cover by rotating counterclockwise.

Bulb Access Cover

5. Disconnect the internal lamp wiring harness connector from the low beam bulb. 6. Rotate the bulb counterclockwise a quarter
turn to unlock the bulb from the lamp.
7. Pull the bulb straight out from the housing.
8. Reverse the procedure for installation of new bulb and covers.
High Beam
See below steps to replace:

1. Open the hood.

2. Disconnect and isolate the negative battery cable.

Bulb Access Cover

3. Look under the hood and behind the headlamp to find the high beam bulb
access cover. 4. Reach behind the headlamp and disengage
the access cover by rotating counter -
clockwise.
5. Disconnect the internal lamp wiring harness connector from the high beam bulb.
6. Rotate the bulb counterclockwise a quarter turn to unlock the bulb from the lamp.
7. Pull the bulb straight out from the housing.
8. Reverse the procedure for installation of new bulb and covers.
CAUTION!
Do not contaminate the bulb glass by
touching it with your fingers or by allowing it
to contact other oily surfaces. Shortened
bulb life will result.

Always use the correct bulb size and type for
replacement. An incorrect bulb size or type
may overheat and cause damage to the
lamp, the bulb socket, or the lamp wiring.

CAUTION!
Do not contaminate the bulb glass by
touching it with your fingers or by allowing it
to contact other oily surfaces. Shortened
bulb life will result.
Always use the correct bulb size and type
for replacement. An incorrect bulb size or
type may overheat and cause damage to
the lamp, the bulb socket, or the lamp
wiring.
8

21_DPF_OM_EN_USC_t.book Page 403

416SERVICING AND MAINTENANCE
Radial Ply Tires
Tire Repair
If your tire becomes damaged, it may be
repaired if it meets the following criteria:
The tire has not been driven on when flat.
The damage is only on the tread section of
your tire (sidewall damage is not repairable).
The puncture is no greater than a ¼ of an
inch (6 mm).
Consult an authorized tire dealer for tire repairs
and additional information.

Damaged Run Flat tires, or Run Flat tires that have
experienced a loss of pressure should be replaced
immediately with another Run Flat tire of identical
size and service description (Load Index and Speed
Symbol). Replace the tire pressure sensor as well as
it is not designed to be reused.

Run Flat Tires — If Equipped
Run Flat tires allow you the capability to drive
50 miles (80 km) at 50 mph (80 km/h) after a
rapid loss of inflation pressure. This rapid loss
of inflation is referred to as the Run Flat mode.
A Run Flat mode occurs when the tire inflation
pressure is of/or below 14 psi (96 kPa). Once a
Run Flat tire reaches the Run Flat mode it has
limited driving capabilities and needs to be
replaced immediately. A Run Flat tire is not
repairable. When a Run Flat tire is changed
after driving with underinflated tire condition,
please replace the TPM sensor as it is not
designed to be reused when driven under Run
Flat mode 14 psi (96 kPa) condition.
NOTE:
TPM Sensor must be replaced after driving the
vehicle on a flat tire condition.
It is not recommended driving a vehicle loaded
at full capacity or to tow a trailer while a tire is in
the Run Flat mode.
See the tire pressure monitoring section for
more information.
Tire Spinning
When stuck in mud, sand, snow, or ice
conditions, do not spin your vehicle's wheels
above 30 mph (48 km/h) or for longer than
30 seconds continuously without stopping.WARNING!

Combining radial ply tires with other types of tires
on your vehicle will cause your vehicle to handle
poorly. The instability could cause a collision.
Always use radial ply tires in sets of four. Never
combine them with other types of tires.

WARNING!

Fast spinning tires can be dangerous. Forces
generated by excessive wheel speeds may
cause tire damage or failure. A tire could
explode and injure someone. Do not spin your
vehicle's wheels faster than 30 mph (48 km/h)
for more than 30 seconds continuously when
you are stuck, and do not let anyone near a
spinning wheel, no matter what the speed.

21_DPF_OM_EN_USC_t.book Page 416

SERVICING AND MAINTENANCE417
Tread Wear Indicators
Tread wear indicators are in the original
equipment tires to help you in determining
when your tires should be replaced.

Tire Tread

These indicators are molded into the bottom of
the tread grooves. They will appear as bands
when the tread depth becomes a 1/16 of an
inch (1.6 mm). When the tread is worn to the
tread wear indicators, the tire should be
replaced.
Life Of Tire
The service life of a tire is dependent upon
varying factors including, but not limited to:
Driving style.

Tire pressure - Improper cold tire inflation pres -
sures can cause uneven wear patterns to
develop across the tire tread. These abnormal
wear patterns will reduce tread life, resulting in
the need for earlier tire replacement.

Distance driven.
Performance tires, tires with a speed rating of
V or higher, and Summer tires typically have
a reduced tread life. Rotation of these tires
per the vehicle scheduled maintenance is
highly recommended. NOTE:
Wheel valve stem must be replaced as well
when installing new tires due to wear and tear
in existing tires.
Keep dismounted tires in a cool, dry place with
as little exposure to light as possible. Protect
tires from contact with oil, grease, and gasoline.
Replacement Tires

The tires on your new vehicle provide a balance of
many characteristics. They should be inspected
regularly for wear and correct cold tire inflation
pressures. The manufacturer strongly recommends
that you use tires equivalent to the originals in size,
quality and performance when replacement is
needed

Ú
page 417. Refer to the Tire and Loading
Information placard or the Vehicle Certification
Label for the size designation of your tire. The Load
Index and Speed Symbol for your tire will be found
on the original equipment tire sidewall.

For more information relating to the Load Index
and Speed Symbol of a tire Ú page 406.
It is recommended to replace the two front tires
or two rear tires as a pair. Replacing just one tire
can seriously affect your vehicle’s handling.
1 — Worn Tire
2 — New Tire
WARNING!
Tires and the spare tire should be replaced
after six years, regardless of the remaining
tread. Failure to follow this warning can result
in sudden tire failure. You could lose control
and have a collision resulting in serious injury
or death.
8

21_DPF_OM_EN_USC_t.book Page 417