Dual Rear WheelsThe tires used on dual wheel assemblies should be
matched for wear to prevent overloading one tire in a set.
To check if tires are even, lay a straight edge across all
four tires. The straight edge should touch all the tires.
CAUTION!
3500 Dual Rear Tires have only one approved direc-
tion of rotation. This is to accommodate the asym-
metrical design (tread pattern) of the ON/OFF road
tire and the use of Outline White Letter (OWL) tires.•
When replacing a flat, the spare tire may have to
be remounted on the rim, or installed at a different
location, to maintain the correct placement of the
tire on the wheel relative to the tire/wheel position
on the truck. For example, if the spare is used to
replace an outer rear tire it will have to be re-
mounted on the rim so that the wheel is dished
inward. That way the tread design of asymmetrical
tires and the white writing of the OWL tires will
maintain proper position.
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5
TIRE PRESSURE MONITOR SYSTEM (TPMS) — IF
EQUIPPEDThe Tire Pressure Monitoring System (TPMS) will warn
the driver of a low tire pressure based on the vehicle
recommended cold tire inflation placard pressure. The
placard pressure is defined on the Tire and Loading
Information label. The Tire and Loading Information
label is located on the drivers side B-pillar. Vehicles
equipped to be operated in either the “max load inflation
pressure” condition described on the Tire and Loading
Information label or the alternative “light load inflation
pressure” condition described on the Supplemental Tire
Pressure Information label, may also be equipped with a
“Tire Light Load Inflation” switch to choose the appro-
priate TPMS low pressure warning threshold levels
based upon the vehicle load condition. The Supplemental
Tire Pressure Information label is located on the rear face
of the driver door. Operation of the “Tire Light Load
Inflation” switch is described later in this manual section.The tire pressure will vary with temperature by approxi-
mately 1 psi (6.9 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 a vehicle has not been driven for
more than three hours, or driven less than 1 mile (1.6 km)
after a three-hour period. For information on how to
properly inflate the vehicle’s tires, refer to ”Tire Pressure”
under “Tires – General Information” in this section. The
tire pressure will also increase as the vehicle is driven -
this is normal and there should be no adjustment for this
increased pressure.
The TPM System will warn the driver of a low tire
pressure if the tire pressure falls below the low pressure
warning threshold for any reason, including low tem-
perature effects, or natural pressure loss through the tire.366 STARTING AND OPERATING
The TPM System 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 recom-
mended cold placard pressure. Once the low tire pressure
warning has been illuminated, the tire pressure must be
increased to the recommended cold placard pressure in
order for the TPMS warning light to be turned off. The
system will automatically update and the TPMS warning
light will extinguish once the updated tire pressures have
been received. The vehicle may need to be driven for up
to 20 minutes above 15 mph (25 km/h) to receive this
information.As an example, assume your vehicle has a recommended
cold tire inflation placard pressure (parked for more than
3 hours) of 35 psi (241 kPa). If the ambient temperature is
68°F (20°C) and the measured tire pressure is 30 psi
(207 kPa), a temperature drop to 20°F (-7°C) will decrease
the tire pressure to approximately 26 psi (179 kPa). This
tire pressure is sufficiently low enough to turn ON the
“Tire Pressure Monitoring Telltale Light.” Driving the
vehicle may cause the tire pressure to rise to approxi-
mately 30 psi (207 kPa), but the “Tire Pressure Monitor-
ing Telltale Light” will still be ON. In this situation, the
“Tire Pressure Monitoring Telltale Light” will turn OFF
only after the tires have been inflated to the vehicle’s
recommended cold tire placard pressure value.
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CAUTION!
•
The TPMS has been optimized for the original
equipment tires and wheels. TPMS pressures 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. After-market wheels can cause sensor dam-
age. Do not use aftermarket tire sealants or balance
beads if your vehicle is equipped with a TPMS, as
damage to the sensors may result.
•
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 Tire Pressure Moni-
toring Sensor.NOTE:
•
The TPMS is not intended to replace normal tire care
and maintenance, nor to provide warning of a tire
failure or condition.
•
The TPMS should not be used as a tire pressure gauge
while adjusting your tire pressure.
•
Driving on a significantly under-inflated tire causes
the tire to overheat and can lead to tire failure.
Under-inflation 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 mainte-
nance, and it is the driver ’s responsibility to maintain
correct tire pressure, even if under-inflation has not
reached the level to trigger illumination of the “Tire
Pressure Monitoring Telltale Light.”
•
Seasonal temperature changes will affect tire pressure,
and the TPM system will monitor the actual tire
pressure in the tire.
368 STARTING AND OPERATING
Tire Pressure Monitor System (TPMS) Tire Light
Load Inflation Switch Description – If Equipped
WARNING!
Never operate your vehicle with the TPMS and tire
pressures set to the Light Load Inflation Pressure
settings if carrying more than two occupants (150 lbs
[68 kg] each) plus 200 pounds (91 kg) of cargo. The
vehicle “Light Load Definition” is found in the
Supplemental Tire Pressure Information Label which
is located on the rear face of the driver door. Failure
to do so may cause you to lose control resulting in an
accident, causing serious or fatal injury.The TPMS tire light load inflation switch will allow the
driver to switch between the max load inflation pressure
(cold) low pressure warning threshold and the light load
inflation pressure (cold) low pressure warning threshold
depending on the vehicle’s load condition. The Tire and
Loading Information label defines the recommended frontand rear cold tire inflation pressures for the vehicle when
operating in the Max Load condition. A Supplemental Tire
Pressure Information label is also available defining Light
Load tire inflation pressures when operating in the Light
Load condition. When the tire light load inflation switch
LED is ON, the TPMS is using the light load inflation
pressure (cold) low inflation warning thresholds.
Tire Light Load Inflation Switch
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5
Tire Light Load Inflation Switch Operation – If
Equipped
•
This vehicle may have different recommended tire
pressure values between the front and rear tires as
shown in both the Tire Loading Information Label and
the Supplemental Tire Pressure Information Label. It is
also equipped to be driven with tire pressures appro-
priate to either a Light Load condition or the vehicle
Max Load condition.
•
The tire light load inflation switch will allow the driver
to change between the max load inflation pressure
(cold) low pressure warning threshold and the light
load inflation pressure (cold) low pressure warning
threshold depending on the vehicle’s load condition.
Refer to the “Supplemental Tire Pressure Information”
label for the vehicle’s Light Load inflation pressures
and “Tire and Loading Information” label for the
vehicle’s Max Load inflation pressures.To switch from the max load inflation pressure (cold) low
pressure warning threshold to the light load inflation
pressure (cold) low pressure warning threshold, begin by
placing the ignition switch in the RUN position. Next,
lower all four road tire pressures to the Light Load
Inflation Pressure values as listed on the Supplemental
Example Supplemental Tire Pressure Label
370 STARTING AND OPERATING
Tire Pressure Information label. The Supplemental Tire
Pressure Information label is located on the rear face of
the driver door. Use an accurate tire gauge to check the
tire pressures when lowering all four tire pressures. After
all four tire pressures have been lowered to the Light
Load inflation pressures, press the tire light load inflation
switch. If the tire light load inflation switch’s amber
colored LED turns ON, the TPMS is using the light load
inflation pressure (cold) low pressure warning thresh-
olds.
If the tire light load inflation switch amber colored LED
flashes on and off for 10 seconds, after all four tire
pressures have been lowered to the Light Load inflation
pressures, the pressure in any one of the four tires may
not be at the light load inflation pressure (cold) values as
indicated for the Light Load condition as defined on the
Supplemental Tire Pressure Information label located onthe rear face of the driver door. Using an accurate tire
pressure gauge, re-check the tire pressures for the light
load inflation pressure (cold) value.
WARNING!
It is the driver ’s responsibility to change to the max
load inflation pressure (cold) low pressure warning
threshold condition when not driving in the light
load condition as defined as two occupants (150 lbs
[68 kg] each) plus 200 pounds (91 kg) of cargo. The
vehicle “Light Load Definition” is found in the
Supplemental Tire Pressure Information label lo-
cated on the rear face of the driver door. Failure to do
so may cause you to lose control resulting in an
accident, causing serious or fatal injury.
To switch back to the max load inflation pressure (cold)
low pressure warning threshold, press the tire light load
inflation switch. It is not necessary to first fill the tires to
STARTING AND OPERATING 371
5
the max load inflation pressure (cold) values to switch
the TPMS system to the max load inflation pressure
(cold) low pressure warning threshold. If after pressing
the tire light load inflation switch, and tire pressures are
below the max load inflation pressure (cold) low pressure
warning thresholds, the TPMS low pressure warning
telltale light (located in the instrument cluster) will turn
ON and a chime will sound. The tire pressures are now
required to be inflated to the max load inflation pressure
(cold) values described on the Tire and Loading Informa-
tion label. The Tire and Loading Information label is
located on the drivers side B-pillar. If the tire light load
inflation switch LED turns OFF, the TPMS has been reset
and the TPMS is using the max load inflation pressure
(cold) low pressure warning thresholds.Tire Pressure Monitor System ComponentsThe Tire Pressure Monitor System (TPMS) uses wireless
technology with wheel rim mounted electronic sensors tomonitor 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 your tires regularly and to maintain
the proper pressure.
The Tire Pressure Monitoring System (TPMS) consists of
the following components:
•
Receiver Module
•
Four Wheel Sensors
•
Two Trigger Modules (mounted in the front wheel-
wells)
•
Tire Light Load Inflation Switch (located in the instru-
ment panel)
•
Tire Pressure Monitoring Telltale Light
372 STARTING AND OPERATING