Jeep grand cherokee 2017 User Manual page 105

The Tire Pressure Monitoring System (TPMS)
will warn the driver of a low tire pressure
based on the vehicle recommended cold tire
pressure.
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 tempera-
ture decreases, the tire pressure will de-
crease. 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. Refer to "Tires" in "Servic-
ing And Maintenance" for information on how to
properly inflate the vehicle's tires. 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 TPMS will warn the driver of a low tire
pressure if the tire pressure falls below the
low pressure warning threshold for any rea-
son, including low temperature effects, or
natural pressure loss through the tire.
The TPMS will continue to warn the driver of
low tire pressure as long as the condition ex-
ists, and will not turn off until the tire pressure
is at or above recommended cold tire pressure.
Once the low tire pressure warning has been
illuminated, the tire pressure must be in-
creased to the recommended cold tire pressure
in order for the Tire Pressure Monitoring Tell-
tale Light to be turned off.
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 plac-
ard pressure in order to turn the Tire Pressure
Monitoring Telltale Light off.
The system will automatically update and the
Tire Pressure Monitoring Telltale 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
(24 km/h) to receive this information.
For example, your vehicle has a recommended
cold (parked for more than three hours) tire
pressure of 33 psi (227 kPa). If the ambient
temperature is 68°F (20°C) and the measured
tire pressure is 28 psi (193 kPa), a tempera-
ture drop to 20°F (-7°C) will decrease the tire
pressure to approximately 24 psi (165 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 approximately 28 psi
(193 kPa), but the Tire Pressure Monitoring
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 pres-
sure value.
CAUTION!
• The TPMS has been optimized for the
original equipment tires and wheels.
TPMS pressures and warnings have
been established for the tire size
equipped on your vehicle. Undesirable
system operation or sensor damage may
result when using replacement equip-
ment that is not of the same size, type,
and/or style. The TPM sensor is not de-
signed for use on aftermarket wheels
and may contribute to a poor overall
system performance or sensor damage.
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