The indirect tire pressure monitoring system, also known as a simplified tire pressure monitoring system, utilizes the wheel speed sensors of the anti-lock braking system (ABS) to compare the speed differences between the tires, thereby obtaining a simulated tire pressure signal. When the air pressure in a tire is too low, the weight of the vehicle causes the diameter of that tire to decrease, making it rotate faster than the other wheels. The speed difference between the left and right wheels triggers a 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.