What does 20% mean in passive tire pressure monitoring?
2 Answers
Passive tire pressure monitoring alerts when tire pressure drops by 20% or more at speeds between 43 km/h and 100 km/h. Tire pressure monitoring light: The tire pressure monitoring indicator is a yellow symbol, an irregular circle with no seal on top, four small spikes at the bottom, and an exclamation mark inside. The tire pressure monitoring indicator light indicates abnormal tire pressure. Abnormal tire pressure generally has the following three causes: Abnormal tire pressure: Generally, an alert is triggered when the pressure is below 1.8 bar or above 3.0 bar. At this time, tire inspection and pressure adjustment are required. Tire pressure monitoring not reset: After inflating the tires, if the tire pressure is not reset in time, the system will still record the previous data, causing the tire pressure monitoring indicator light to turn on. In this case, simply reset the tire pressure. Damaged tire pressure sensor: The tire pressure sensor is used to monitor tire pressure and is directly installed inside the tire, connected to the tire inflation port. If the sensor is damaged due to impact while driving, it can also cause the tire pressure warning light to turn on. For sensor damage issues, only replacement with a new part is possible. What to do if tire pressure is insufficient: If no damage is visible, simply inflate to normal pressure and reset the tire pressure system; If inspection reveals a puncture, drive to a tire shop promptly for repair, then reinflate; If the system indicates insufficient pressure after inflation but there is no puncture, it may be due to air leakage caused by a deformed wheel rim. It is recommended to check the wheel rim and replace it if necessary.
A 20% reading on the passive tire pressure monitoring system indicates that the tire pressure is a full 20% below the recommended normal value. For example, if the manufacturer recommends a tire pressure of 35 psi, a 20% decrease would mean it's only around 28 psi. The system alerts by directly measuring the pressure in each tire. Once the warning light comes on, you need to address it immediately because low tire pressure makes tires more prone to overheating and wear, reduces grip, increases braking distance, and could even lead to a blowout at high speeds. I recommend pulling over safely to check for leaks or punctures, or heading to the nearest gas station to inflate the tires to the standard value. Developing a habit of checking tire pressure regularly can prevent such issues—for instance, I always take a quick look whenever I wash my car.
