Jeep 2012 Grand Cherokee - Owner Manual - Manual (Page 509)

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 ЉSERVICE TPM SYSTEMЉ
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
ЉSERVICE TPM SYSTEMЉ
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
ЉSERVICE TPM SYSTEMЉ 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 Pres-
sure Monitoring Telltale Light will remain ON, a chime
will sound, and the EVIC will still display a “flashing”
pressure value in the graphic display. 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
Љ mes-
sage for five seconds and then display dashes (- -) in
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