2023 RAM CHASSIS CAB tire size

182STARTING AND OPERATING
The recommended way to measure GTW is to put
your fully loaded trailer on a vehicle scale. The
entire weight of the trailer must be supported by
the scale.
Gross Combination Weight Rating (GCWR)
The GCWR is the total allowable weight of your
vehicle and trailer when weighed in combination.
Gross Axle Weight Rating (GAWR)
The GAWR is the maximum capacity of the front
and rear axles. Distribute the load over the front
and rear axles evenly. Make sure that you do not
exceed either front or rear GAWR Ú page 180.
Tongue Weight (TW)
The TW is the downward force exerted on the hitch
ball by the trailer. You must consider this as part of
the load on your vehicle.
Trailer Frontal Area
The frontal area is the maximum height multiplied
by the maximum width of the front of a trailer.
Trailer Sway Control (TSC)
The TSC can be a mechanical telescoping link that
can be installed between the hitch receiver and the
trailer tongue that typically provides adjustable
friction associated with the telescoping motion to
dampen any unwanted trailer swaying motions
while traveling. If equipped, the electronic TSC recognizes a
swaying trailer and automatically applies individual
wheel brakes and/or reduces engine power to
attempt to eliminate the trailer sway.
Weight-Carrying Hitch
A weight-carrying hitch supports the trailer tongue
weight, just as if it were luggage located at a hitch
ball or some other connecting point of the vehicle.
These kinds of hitches are commonly used to tow
small and medium sized trailers.
Weight-Distributing Hitch
A weight-distributing hitch system works by
applying leverage through spring (load) bars. They
are typically used for heavier loads to distribute
trailer tongue weight to the tow vehicle's front axle
and the trailer axle(s). When used in accordance
with the manufacturer's directions, it provides for a
more level ride, offering more consistent steering
and brake control, thereby enhancing towing
safety. The addition of a friction/hydraulic sway
control also dampens sway caused by traffic and
crosswinds and contributes positively to tow
vehicle and trailer stability. Trailer Sway Control
(TSC) and a weight-distributing (load equalizing)
hitch are recommended for heavier Tongue
Weights (TW) and may be required depending on
vehicle and trailer configuration/loading to comply
with GAWR requirements.
WARNING!
If the gross trailer weight is 5,000 lb (2,267 kg)
or more, it is recommended to use a
weight-distributing hitch to ensure stable
handling of your vehicle. If you use a standard
weight-carrying hitch, you could lose control of
your vehicle and cause a collision.
WARNING!
It is important that you do not exceed the
maximum front or rear GAWR. A dangerous
driving condition can result if either rating is
exceeded. You could lose control of the vehicle
and have a collision.

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STARTING AND OPERATING187
(Continued)
(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 389.
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 inadequate 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 lb (453 kg) and required for trailers
in excess of 2,000 lb (907 kg).
When hauling cargo or towing a trailer, do not
overload your vehicle or trailer. Overloading
can cause a loss of control, poor performance
or damage to brakes, axle, engine, transmis -
sion, 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.
WARNING!
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!
WARNING!
Do not connect trailer brakes to your vehicle's
hydraulic brake lines. It can overload your
brake system and cause it to fail. You might
not have brakes when you need them and
could have an accident.
4

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SAFETY273
(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.
NOTE:For vehicles with multiple partial ESC modes, the
push and release of the button may toggle the ESC
modes. Multiple attempts may be required to
return to "ESC On" mode.
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 condi
-
tions. ESC cannot prevent accidents, including
those resulting from excessive speed in turns,
driving on very slippery surfaces, or hydro -
planing. 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 accidents. 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 mainte -
nance that reduces the effectiveness of the
ESC system can increase the risk of loss of
vehicle control, vehicle rollover, personal
injury and death.
WARNING!
WARNING!
When in “Partial Off” mode, the TCS function -
ality of ESC, except for the limited slip feature
described in the TCS section, has been
disabled and the ESC OFF Indicator Light will
be illuminated. When in “Partial Off” mode,
the engine power reduction feature of TCS is
disabled, and the enhanced vehicle stability
offered by the ESC system is reduced.
Trailer Sway Control (TSC) is disabled when
the ESC system is in the “Partial Off” mode.
6

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SAFETY281
each tire with the low tire pressure 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 Ú page 389 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 427.
CAUTION!
The TPMS has been optimized for the original
equipment tires and wheels. TPMS pressures
and warning have been established 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 pressure
always reinstall the valve stem cap. This will
prevent moisture and dirt from entering the
valve stem, which could damage the TPMS
sensor.
6

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SAFETY283
display in the instrument cluster will return to its
original color, and the Tire Pressure Monitoring
System Warning Light will turn off. 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 Tire Pressure Monitoring System
Warning Light off.
Service TPMS Warning
If a system fault is detected, the Tire Pressure
Monitoring System Warning Light will flash on and
off for 75 seconds and then remain on solid. In
addition, 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 to indicate which
sensor is not being received.
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 Warning Light will no longer
flash, and the "SERVICE TPM SYSTEM" message
will no longer display, and a pressure 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 Warning 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. There
-
fore, 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 addi-
tion, 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 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.

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.
6

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284SAFETY
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-pres -
sure 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.
Trailer Tire Pressure Monitoring System
(TTPMS) — If Equipped
The Trailer Tire Pressure Monitoring System
(TTPMS) is a feature that displays the trailer tire
pressure values and warns the driver of a low tire
pressure event based on the driver’s set target tire
pressure value, through TTPMS settings found in
the radio.

The TTPMS monitors the pressure of each tire and
warns the driver through the instrument cluster, when
either a low tire pressure condition falls below 25% of
the driver’s set pressure or if a system malfunction
occurs. The instrument cluster will display the actual
tire pressure or dashes for each of the trailer tires in
the correct trailer position, based on trailer
configuration. The TTPMS can support up to 12 trailer
tires per configured trailer on up to four configurable
trailers
Ú
page 199.
Trailer Tire Pressure Monitoring System

Trailer Tire Pressure Sensor Pairing
In order use this feature, the provided tire pressure
sensors must be installed in the desired trailer
tires and the sensors must be paired to the truck.
If the target trailer requires more than the provided
four sensors, additional sensors can be purchased
at an authorized Ram dealership.
With the sensors installed and the trailer near or
connected to your Ram truck, initiate the pairing
process by entering the settings menu in the radio
and select trailer. Select the desired trailer profile
to pair to, open the “Tire Pressure” menu, and hit
“Set Up All Tires” Ú page 199.
NOTE:The vehicle may not be driven until the pairing
process is complete.
Trailer Tire Pressure Settings
Trailer Tire Pressure Pairing

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SERVICING AND MAINTENANCE389

Removing Bulb Socket From Clearance Lamp

3. Pull the bulb straight from it's socket and replace.
TIRES
TIRE SAFETY INFORMATION
Tire safety information will cover aspects of the
following information: Tire Markings, Tire
Identification Numbers, Tire Terminology and
Definitions, Tire Pressures, and Tire Loading.
Tire Markings

Tire Markings

NOTE:
P (Passenger) — Metric tire sizing is based on US
design standards. P-Metric tires have the letter
“P” molded into the sidewall preceding the size
designation. Example: P215/65R15 95H.
European — Metric tire sizing is based on Euro -
pean design standards. Tires designed to this
standard have the tire size molded into the side -
wall beginning with the section width. The letter
"P" is absent from this tire size designation.
Example: 215/65R15 96H.
LT (Light Truck) — Metric tire sizing is based on
US design standards. The size designation for
LT-Metric tires is the same as for P-Metric tires
except for the letters “LT” that are molded into
the sidewall preceding the size designation.
Example: LT235/85R16.
Temporary spare tires are designed for tempo -
rary emergency use only. Temporary high pres -
sure compact spare tires have the letter “T” or
“S” molded into the sidewall preceding the size
designation. Example: T145/80D18 103M.
High flotation tire sizing is based on US design
standards and it begins with the tire diameter
molded into the sidewall. Example: 31x10.5
R15 LT.
1 — US DOT Safety Standards Code
(TIN)
2 — Size Designation
3 — Service Description
4 — Maximum Load
5 — Maximum Pressure
6 — Treadwear, Traction and
Temperature Grades
8

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390SERVICING AND MAINTENANCE
TIRE SIZING CHART
EXAMPLE:
Example Size Designation: P215/65R15XL 95H, 215/65R15 96H, LT235/85R16C, T145/80D18 103M, 31x10.5 R15 LT
P = Passenger car tire size based on US design standards, or
"....blank...." = Passenger car tire based on European design standards, or
LT = Light truck tire based on US design standards, or
T or S = Temporary spare tire or
31 = Overall diameter in inches (in)
215, 235, 145 = Section width in millimeters (mm)
65, 85, 80 = Aspect ratio in percent (%)
Ratio of section height to section width of tire, or
10.5 = Section width in inches (in)
R = Construction code
"R" means radial construction, or
"D" means diagonal or bias construction
15, 16, 18 = Rim diameter in inches (in)

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