Jeep 2004 Grand Cherokee Owner's Manual page 104

104 UNDERSTANDING THE FEATURES OF YOUR VEHICLE
Tire Pressure Display — If Equipped
Shows the current pressure of all 4 road tires.
NOTE: Tires heat up during normal driving conditions.
Heat will cause the tire pressure to increase from 2 to 6
psi (14 to 41 kPa) during normal driving conditions. Refer
to "Tire Inflation Pressures" in Section 5 for additional
information.
Blank Screen
Shows a blank screen. Pressing the C/T button returns to
the compass/temperature display.
Automatic Compass Calibration
This compass is self-calibrating which eliminates the
need to manually set the compass. When the vehicle is
new, the compass may appear erratic and the CAL
symbol will be displayed.
After completing one 360 degree turn, with the vehicle
traveling less than 5 mph (8 km/h), in an area free from
large metal or metallic objects, the CAL symbol will turn
off and the compass will function normally.
Manual Compass Calibration
If the compass appears erratic and the CAL symbol does
not appear, you must manually put the compass into the
"Calibration" mode.