2004 Chevrolet Impala Owner's Manual - Page 330

The system normally takes 15 to 20 minutes of driving in each of three speed ranges to ″learn″ tire pressures. The speed ranges are 15 to 4 mph (25 to 65 km/h), 40 to 65 mph (65 to 105 km/h) and above 65 mph (105 km/h). When learning is complete, the system will alert you after two to eight minutes if a tire is 12 psi (83 kPa) different from the other three tires. Detection thresholds may be higher and detection times may be longer on rough roads, curves and at high speeds. The system is not capable of detection at speeds greater than 70 mph (110 km/h). Tire Inspection and Rotation Tires should be rotated every 5,000 to 8,000 miles (8 000 to 13 000 km). Any time you notice unusual wear, rotate your tires as soon as possible and check wheel alignment. Also check for damaged tires or wheels. See When It Is Time for New Tires on page 5-69 and Wheel Replacement on page 5-72 for more information. The purpose of regular rotation is to achieve more uniform wear for all tires on the vehicle. The first rotation is the most important. See Scheduled Maintenance on page 6-4 for scheduled rotation intervals. When rotating your tires, always use the correct rotation pattern shown here. Don't include the compact spare tire in your tire rotation. After the tires have been rotated, adjust the front and rear inflation pressures as shown on the Tire and Loading Information label. Reset the Tire Inflation Monitor System. See Tire Pressure Monitor System on page 5-66. 5-68