Indirect Tire Pressure Monitoring System Principle
Also known as a simplified tire pressure monitoring system, it uses the wheel speed sensors of the ABS system to compare the wheel speed differences between the tires to obtain a simulated tire pressure signal. When the tire pressure of a particular tire is too low, the weight of the car causes the tire diameter to decrease, resulting in its rotation speed being faster than other wheels. This difference in the number of revolutions between the left and right wheels triggers the tire pressure warning.
Advantages of Indirect Tire Pressure Monitoring System (TPMS):For vehicles equipped with ABS, only a software upgrade is needed, making it relatively low-cost.
Disadvantages of Indirect Tire Pressure Monitoring System (TPMS):
Slow Response: Leaking tires often only trigger an alarm several kilometers after the vehicle has driven.
Inaccurate Calculation: Wheel speed sensors measure wheel speed differences, simulating tire pressure signals, resulting in inaccurate calculations.
No Alarm at Extreme Speeds: No alarm is triggered at speeds ≥100 km/h or ≤40 km/h.
No Alarm for Tire Pressure Issues on the Same Axle: If two or all four tires on the same axle have abnormal pressure but rotate at the same speed, no alarm will be triggered.
Uncertain Tire Position: Only a warning symbol is displayed, without identifying the faulty tire (left front/left rear/right front/right rear). 6. Only low tire pressure alarm: It does not alarm for tire leaks, high temperature, or excessive tire pressure.
Frequent false alarms: False alarms frequently occur during rapid turns, driving on snow or slippery surfaces, and are easily ignored by the driver.
No real-time display: It is not intuitive and does not allow the driver to know the current tire pressure and temperature values at any time.