Jeep Grand Cherokee 2013 Owner's Manual page 555

message will not be present, and a pressure value will be
displayed instead of dashes. 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.
The EVIC will also display a SERVICE TPM SYSTEM
message for a minimum of five seconds when a system
fault is detected possibly related to an incorrect sensor
location fault. In this case, the SERVICE TPM SYSTEM
message is then followed by a graphic display, with
pressure values still shown. This indicates the pressure
values are still being received from the TPM Sensors but
they may not be located in the correct vehicle position.
However, the system still needs to be serviced as long as
the SERVICE TPM SYSTEM message exists.
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, the Tire Pressure Moni-
toring Telltale Light will remain ON, a chime will sound,
and the EVIC will still display a "flashing" pressure value in
the graphic display and an Inflate to XXX kPa message will
be displayed. 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, the EVIC will display a
"SERVICE TPM SYSTEM message for five seconds and then
display dashes (- -) in place of the pressure value. For each
subsequent ignition switch cycle, a chime will sound, the
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