2003 Chevrolet Impala Owner's Manual - Page 315

Tire Pressure Monitor System If your vehicle has the tire pressure monitor system, it can alert you to a large change in the pressure of one tire. The system "learns" the pressure at each tire throughout the operating speed range of your vehicle. The system normally takes between 45 and 90 minutes of driving to learn the tire pressures. This time may be longer depending on your individual driving habits. Learning need not be accumulated during a single trip. Once learned, the system will remember the tire pressures until the system is recalibrated. When the LOW TIRE PRESSURE message comes on, you should stop as soon as you can and check all your tires for damage. (If a tire is flat, see If a Tire Goes Flat on page 5-70) Also check the tire pressure in all four tires as soon as you can. See lnflation -- Tire Pressure on page 5-61. The LOW TIRE PRESSURE message will also be displayed (while the ignition is on) until you reset (calibrate) the system. Don't reset the tire pressure monitor system without first correcting the cause of the problem and checking and adjusting the pressure in all four tires. If you reset the system when the tire pressures are incorrect, the system will not work properly and may not alert you when a tire is low. Any time you adjust a tire's pressure, rotate your tires, or have one or more tiresrepaired or replaced, you'll need to reset (calibrate) the tire pressure monitor system. You'll also need to reset the system whenever you buy new tires and whenever the vehicle's battery has been disconnected. To reset (calibrate) the system: The tire pressure monitor system can be reset two ways. With the ignition position at ON, pull the interior lamps control to the ON and OFF settings three times. After the system has learned tire pressures with properly inflated tires, the LOW TIRE PRESSURE message will come on if the pressure in one tire becomes 12 psi (83 kPa) lower than the other three tires. The tire pressure monitor system won't alert you if the pressure in more than one tire is low, if the system is not properly calibrated, or if the vehicle is moving faster than 70 mph (110 km/h). The tire pressure monitor system detects differences in tire rotation speeds that are caused by changes in tire pressure. The system can alert you about a low tire - but it doesn't replace normal tire maintenance. See Tires on page 5-60. 5-62