tire size RAM CHASSIS CAB 2023 User Guide

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.
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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.
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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.
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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
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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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392SERVICING AND MAINTENANCE
Tire Identification Number (TIN)
The TIN may be found on one or both sides of the tire; however, the date code may only be on one side. Tires with white sidewalls will have the full TIN, including
the date code, located on the white sidewall side of the tire. Look for the TIN on the outboard side of black sidewall tires as mounted on the vehicle. If the TIN is
not found on the outboard side, then you will find it on the inboard side of the tire.
EXAMPLE:
DOT MA L9 ABCD 0301
DOT = Department of Transportation
This symbol certifies that the tire is in compliance with the US Department of Transportation tire safety standards and is approved for highway use
MA = Code representing the tire manufacturing location (two digits)
L9 = Code representing the tire size (two digits)
ABCD = Code used by the tire manufacturer (one to four digits)
03 = Number representing the week in which the tire was manufactured (two digits)
03 means the 3rd week
01 = Number representing the year in which the tire was manufactured (two digits)
01 means the year 2001
Prior to July 2000, tire manufacturers were only required to have one number to represent the year in which the tire was manufactured. Example: 031 could
represent the 3rd week of 1981 or 1991

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SERVICING AND MAINTENANCE393
Tire Terminology And Definitions
Term Definition
B-pillarThe vehicle B-pillar is the structural member of the body located behind the
front door.
Cold Tire Inflation Pressure Cold tire inflation pressure 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 sitting for a minimum of three hours. Inflation pressure is measured in
units of psi (pounds per square inch) or kPa (kilopascals).
Maximum Inflation Pressure The maximum inflation pressure is the maximum permissible cold tire
inflation pressure for this tire. The maximum inflation pressure is molded into
the sidewall.
Recommended Cold Tire Inflation Pressure Vehicle manufacturer's recommended cold tire inflation pressure as shown
on the tire placard.
Tire Placard A label permanently attached to the vehicle describing the vehicle’s loading
capacity, the original equipment tire sizes and the recommended cold tire
inflation pressures.
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394SERVICING AND MAINTENANCE
Tire Loading And Tire Pressure
NOTE:The proper cold tire inflation pressure is listed on
the driver’s side B-pillar or the rear edge of the
driver's side door.
Check the inflation pressure of each tire, including
the spare tire (if equipped), at least monthly and
inflate to the recommended pressure for your
vehicle.

Example Tire Placard Location (Door) Example Tire Placard Location (B-pillar)

Tire And Loading Information Placard

Tire And Loading Information Placard
This placard tells you important information about
the:

1. Number of people that can be carried in the
vehicle.

2. Total weight your vehicle can carry.
3. Tire size designed for your vehicle.
4. Cold tire inflation pressures for the front, rear, and spare tires.
Loading
The vehicle maximum load on the tire must not
exceed the load carrying capacity of the tire on your
vehicle. You will not exceed the tire's load carrying
capacity if you adhere to the loading conditions,
tire size, and cold tire inflation pressures specified
on the Tire And Loading Information Placard
Úpage 180.
NOTE:Under a maximum loaded vehicle condition, gross
axle weight ratings (GAWR) for the front and rear
axles must not be exceeded.
For further information on GAWR, vehicle loading,
and trailer towing Ú page 180.

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SERVICING AND MAINTENANCE395
To determine the maximum loading conditions of
your vehicle, locate the statement “The combined
weight of occupants and cargo should never
exceed XXX kg or XXX lbs” on the Tire And Loading
Information Placard. The combined weight of
occupants, cargo/luggage and trailer tongue
weight (if applicable) should never exceed the
weight referenced here.
Steps For Determining Correct Load Limit—
(1) Locate the statement “The combined
weight of occupants and cargo should
never exceed XXX kg or XXX lbs.” on your
vehicle's placard.
(2) Determine the combined weight of
the driver and passengers that will be
riding in your vehicle.
(3) Subtract the combined weight of the
driver and passengers from XXX kg or
XXX lbs. (4) The resulting figure equals the
available amount of cargo and luggage
load capacity. For example, if “XXX”
amount equals 1400 lbs. and there will
be five 150 lb passengers in your
vehicle, the amount of available cargo
and luggage load capacity is 650 lbs.
(1400-750 (5x150) = 650 lbs.)
(5) Determine the combined weight of
luggage and cargo being loaded on the
vehicle. That weight may not safely
exceed the available cargo and luggage
load capacity calculated in Step 4.
(6) If your vehicle will be towing a trailer,
load from your trailer will be transferred
to your vehicle. Consult this manual to
determine how this reduces the
available cargo and luggage load
capacity of your vehicle.
Metric Example For Load Limit
For example, if “XXX” amount equals 635 kg and
there will be five 68 kg passengers in your vehicle,
the amount of available cargo and luggage load
capacity is 295 kg (635-340 (5x68) = 295 kg) as
shown in step 4.
NOTE:
If your vehicle will be towing a trailer, load from
your trailer will be transferred to your vehicle.
The following table shows examples on how to
calculate total load, cargo/luggage, and towing
capacities of your vehicle with varying seating
configurations and number and size of occu
-
pants. This table is for illustration purposes only
and may not be accurate for the seating and
load carry capacity of your vehicle.
For the following example, the combined weight
of occupants and cargo should never exceed
865 lbs (392 kg).
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