Jeep Wrangler2018 Owner's Manual page 231

If the ignition key is cycled, this sequence will repeat,
providing the system fault still exists. If the system fault no
longer exists, the Tire Pressure Monitoring Telltale Light
will no longer flash, and the "SERVICE TIRE PRESSURE
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:
• Jamming due to electronic devices or driving next to
facilities emitting the same radio frequencies as the
TPMS sensors.
• Installing some form of aftermarket window tinting that
affects radio wave signals.
• Lots of snow or ice around the wheels or wheel hous-
ings.
• Using tire chains on the vehicle.
• Using wheels/tires not equipped with TPMS sensors.
Vehicles With Compact Spare or Non-Matching Full Size
Spare
1. The compact spare tire or non-matching full size does
not have a tire pressure monitoring sensor. Therefore,
the TPMS will not monitor the pressure in the compact
spare tire.
2. If you install the compact or non-matching full size
spare tire in place of a road tire that has a pressure below
the low-pressure warning limit, upon the next ignition
key cycle, the TPMS Telltale Light will remain on and a
chime will sound. In addition, the graphic in the instru-
ment cluster will still display a different color pressure
value and an Inflate to XX message.
3. After driving the vehicle for up to 20 minutes above
15 mph (24 km/h), the TPMS Telltale Light will flash on
and off for 75 seconds and then remain on solid. In
addition, the instrument cluster will display a "Service
Tire Pressure System" message for five seconds and then
display dashes (- -) in place of the pressure value.
4. For each subsequent ignition key cycle, a chime will
sound, the TPMS Telltale Light will flash on and off for
75 seconds and then remain on solid, and the instrument
cluster will display a "SERVICE TIRE PRESSURE SYS-
TEM" message for five seconds and then display dashes
(- -) in place of the pressure value.
5. Once you repair or replace the original road tire and
reinstall it on the vehicle in place of the compact spare or
non-matching full size, the TPMS will update automati-
cally. In addition, the TPMS Telltale Light will turn off
and the graphic in the instrument cluster will display a
SAFETY 229
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