I dont know if this has been verified to work with the KJ or not, but here is the procedure to check the tpms system on a WJ. From
www.wjjeeps.com
Quote:
The following test can be used to verify two functions. One, that the tire pressure sensors are transmitting properly and two, the EVIC module is receiving these transmissions accordingly. Using the STEP button on the overhead console, scroll to the blank display, then press the RESET button for five seconds, a beep will sound indicating the start of this test. The vehicle icon and transmission counters will now be displayed, (same display as individual tire pressure except counters replace tire pressure values).
Upon entering the test mode, the EVIC will clear the sensor counter and each time a sensor signal for a road tire is received, the EVIC will update the counter value. The vehicle must be driven to 20-25 mph to initially activate the transmitters, and once activated they will stay activated for 15 minutes after the vehicle stops moving. The counter values should all increment somewhat evenly. If any of the road tires indicate a much different value than another tire sensor, this is a sign of a problem. Replace the appropriate tire sensor and retest the system. This test will continue until any of the overhead console buttons are pressed or the ignition is turned off.