2018 Ram 4500 Chassis Cab wheel size

Your vehicle has also been equipped with a TPMS malfunc-
tion indicator to indicate when the system is not operating
properly. The TPMS malfunction indicator is combined
with the low tire pressure telltale. When the system detects
a malfunction, the telltale will flash for approximately one
minute and then remain continuously illuminated. This
sequence will continue upon subsequent vehicle start-ups
as long as the malfunction exists. When the malfunction
indicator is illuminated, the system may not be able to
detect or signal low tire pressure as intended. TPMS
malfunctions may occur for a variety of reasons, including
the installation of replacement or alternate tires or wheels
on the vehicle that prevent the TPMS from functioning
properly. Always check the TPMS malfunction telltale after
replacing one or more tires or wheels on your vehicle to
ensure that the replacement or alternate tires and wheels
allow the TPMS to continue to function properly.
CAUTION!
The TPMS has been optimized for the original equip-
ment tires and wheels. TPMS pressures and warning
have been established for the tire size equipped on
your vehicle. Undesirable system operation or sensor
(Continued)
CAUTION!(Continued)
damage may result when using replacement equip-
ment 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 inoper-
able. After using an aftermarket tire sealant it is
recommended that you take your vehicle to your au-
thorized dealer to have your sensor function checked.
— Low Fuel Indicator Light
When the fuel level reaches approximately 3.0 gal (11.0 L)
this light will turn on, and remain on until fuel is added.
— Anti-Lock Brake (ABS) Warning Light
This light monitors the Anti-Lock Brake System (ABS). The
light will turn on when the ignition is placed in the
ON/RUN or ACC/ON/RUN position and may stay on for
as long as four seconds.
If the ABS light remains on or turns on while driving, then
the Anti-Lock portion of the brake system is not function-
ing and service is required as soon as possible. However,
the conventional brake system will continue to operate
normally, assuming the Brake Warning Light is not also on.
156 GETTING TO KNOW YOUR INSTRUMENT PANEL

WARNING!(Continued)
and skillful driver can prevent accidents. The capa-
bilities 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 main-
tain your vehicle, may change the handling charac-
teristics 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
performance. Improperly inflated and unevenly
worn tires may also degrade ESC performance. Any
vehicle modification or poor vehicle maintenance
that reduces the effectiveness of the ESC system can
increase the risk of loss of vehicle control, vehicle
rollover, personal injury and death.
ESC Operating Modes
NOTE: 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. 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
The “Partial Off” mode is intended for times when a more
spirited driving experience is desired. This mode may
modify TCS and ESC thresholds for activation, which
allows for more wheel spin than normally allowed. This
mode may be useful if the vehicle becomes stuck.
To enter the “Partial Off” mode, momentarily push the
“ESC Off” switch and the “ESC Off Indicator Light” will
illuminate. To turn the ESC on again, momentarily push
the “ESC Off” switch and the “ESC Off Indicator Light”
will turn off.
NOTE:
For vehicles with multiple partial ESC modes a
momentary button push will toggle the ESC mode. Mul-
tiple momentary button pushed may be required to return
to ESC On.
170 SAFETY

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 tire pressure warning
(Tire Pressure Monitoring [TPM] Telltale Light) illumi-
nates, you must increase the tire pressure to the recom-
mended cold placard pressure in order for the TPM Telltale
Light to turn off. The system will automatically update and
the TPM Telltale 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 (30 kPa) above the
recommended cold placard pressure in order to turn the
Tire Pressure Monitoring Telltale 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 tempera-
ture drop to 20°F (-7°C) will decrease the tire pressure to
approximately 23 psi (158 kPa). This tire pressure is suffi-
ciently low enough to turn on the TPM Telltale Light.
Driving the vehicle may cause the tire pressure to rise to
approximately 27 psi (186 kPa), but the TPM Telltale Light will still be on. In this situation, the TPM Telltale Light will
turn off only after the tires are inflated to the vehicle’s
recommended cold placard pressure value.
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 op-
eration 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 be-
come 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 mois-
ture and dirt from entering the valve stem, which
could damage the TPMS sensor.
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SAFETY 177

flash and the tire pressure display screen will be displayed
showing the tire pressure values 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 TPM 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 TPM Telltale 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.
• After driving the vehicle for up to 20 minutes above
15 mph (24 km/h), the TPM Telltale 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 TPM Telltale 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 TPM Telltale 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.
Tire Pressure Information System (TPIS) Chassis
Cab — If Equipped
Your vehicle may be equipped with a Tire Pressure Infor-
mation System (TPIS).
The Tire Pressure Information System (TPIS) uses wireless
technology with wheel rim mounted electronic sensors to
5
SAFETY 181

buckle switch may adjust the inflation rate of the Ad-
vanced 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 collision 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.
Front Air Bag Operation
Front Air Bags are designed to provide additional protec-
tion 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 sub-
stantial vehicle damage — for example, some pole colli-
sions, 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 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 right 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
200 SAFETY

4L
Four-Wheel Drive Low Range — This range locks the front
and rear driveshafts together forcing the front and rear
wheels to rotate at the same speed. Additional traction and
maximum pulling power for loose, slippery road surfaces
only. Do not exceed 25 mph (40 km/h).
This transfer case is intended to be driven in the 2H
position for normal street and highway conditions such as
dry, hard surfaced roads.
When additional traction is required, the 4H and 4L
positions can be used to lock the front and rear driveshafts
together and force the front and rear wheels to rotate at the
same speed. This is accomplished by simply moving the
gear selector to the desired positions once the appropriate
speed and gear requirements are met, refer to “Shifting
Procedure – Manually Shifted Transfer Case” in this section
for further information.
The 4H and 4L positions are intended for loose, slippery
road surfaces only. Driving in the 4H and 4L positions on
dry, hard surfaced roads may cause increased tire wear and
damage to the driveline components.
The “Transfer Case Position Indicator Light” in the instru-
ment cluster will alert the driver that the vehicle is infour-wheel drive and that the front and rear driveshafts are
locked together. This light will illuminate when the transfer
case is shifted into either the 4H or 4L position. There is no
light for the 2H or NEUTRAL positions on some models.
When operating your vehicle in 4L, the engine speed is
approximately three times that of the 2H or 4H positions at
a given road speed. Take care not to overspeed the engine
and do not exceed 25 mph (40 km/h).
Proper operation of four-wheel drive vehicles depends on
tires of equal size, type and circumference on each wheel.
Any difference will adversely affect shifting and can cause
damage to the drivetrain.
NOTE:
Do not attempt to make a shift while only the front
or rear wheels are spinning, as this can cause damage to
driveline components.
Because four-wheel drive provides improved traction,
there is a tendency to exceed safe turning and stopping
speeds. Do not go faster than road conditions permit.
NOTE: Delayed shifts out of four-wheel drive may be
experienced due to uneven tire wear, low or uneven tire
pressures, excessive vehicle loading, or cold temperatures.
258 STARTING AND OPERATING

3. The transfer casewill notshift.
NOTE: Before retrying a selection, make certain that all
the necessary requirements for selecting a new transfer
case position have been met. To retry the selection, turn the
control switch back to the current position, wait five
seconds, and retry selection. To find the shift requirements,
refer to the Shifting Procedure for your transfer case,
located in this section.
The “SVC 4WD Warning Light” monitors the electronic
shift four-wheel drive system. If this light remains on after
engine start up or illuminates during driving, it means that
the four-wheel drive system is not functioning properly
and that service is required.
WARNING!
Always engage the parking brake when powering
down the vehicle if the “SVC 4WD Warning Light” is
illuminated. Not engaging the parking brake may
allow the vehicle to roll, which may cause personal
injury. NOTE:
Do not attempt to make a shift while only the front
or rear wheels are spinning, as this can cause damage to
driveline components.
When operating your vehicle in 4WD LOW, the engine
speed is approximately three times that of the 2WD or
4WD LOCK positions at a given road speed. Take care not
to overspeed the engine and do not exceed 25 mph
(40 km/h).
Proper operation of four-wheel drive vehicles depends on
tires of equal size, type and circumference on each wheel.
Any difference in tire size can cause damage to the
drivetrain.
Because four-wheel drive provides improved traction,
there is a tendency to exceed safe turning and stopping
speeds. Do not go faster than road conditions permit.
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STARTING AND OPERATING 263

Payload
The payload of a vehicle is defined as the allowable load
weight a truck can carry, including the weight of the driver,
all passengers, options and cargo.
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 in-
creased durability does not necessarily increase the vehi-
cle’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 insure 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 axle. Weighing the
vehicle may show that the GAWR of either the front or rear
axles 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
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STARTING AND OPERATING 291