2012 Jeep Grand Cherokee Owner Manual - Page 507

STARTING AND OPERATING 505 will automatically update and the Tire Pressure Monitoring Telltale Light will extinguish, once the updated tire pressures have been received. The vehicle may need to be driven for up to 20 minutes above 15 mph (24 km/h) to receive this information. 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: 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, and the Tire Pressure Monitoring 1. Jamming due to electronic devices or driving next to Telltale Light will turn ON. After driving the vehicle for facilities emitting the same Radio Frequencies as the TPM up to 20 minutes above 15 mph (24 km/h), the Tire Pressure Monitoring Telltale Light will flash on and off sensors. 5