Jeep Grand Cherokee 2013 Owner's Manual page 551

The Tire Pressure Monitoring Telltale Light will flash on
and off for 75 seconds, and remain on solid when a
system fault is detected. In addition, a "SERVICE TPM
SYSTEM" message may be displayed for approximately
5 seconds when a system fault is detected, and a chime
will sound. If the ignition switch is cycled, this sequence
will repeat, providing the system fault still exists. The
Tire Pressure Monitoring Telltale Light will turn off when
the fault condition no longer exists. A system fault can
occur by any of the following:
1. Jamming due to electronic devices or driving next to
facilities emitting the same Radio Frequencies as the
TPM sensors.
2. Installing some form of aftermarket window tinting
that affects radio wave signals.
3. Lots of snow or ice around the wheels or wheel
housings.
4. Using tire chains on the vehicle.
5. Using wheels/tires not equipped with TPM sensors.
NOTE: There is no tire pressure monitoring sensor in the
spare tire. The TPMS will not be able to monitor the tire
pressure. If you install the spare tire, in place of a road tire,
that has a pressure below the low-pressure warning limit,
upon the next ignition switch cycle, a chime will sound, a
"LOW TIRE PRESSURE" message will be displayed in the
instrument cluster for a minimum of five seconds, an Inflate
to XXX message will be displayed and the Tire Pressure
Monitoring Telltale Light will turn ON. After driving the
vehicle for up to 20 minutes above 15 mph (24 km/h), the
Tire Pressure Monitoring Telltale Light will flash on and off
for 75 seconds and then remain on solid. In addition, a
"SERVICE TPM SYSTEM" message will be displayed for a
minimum of five seconds. For each subsequent ignition
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