How does an indirect TPMS work?

There are three principles of tire pressure monitoring in automobiles1Direct tire pressure monitoring direct tire pressure monitoring device is to use the pressure sensor installed in each tire to directly measure the air pressure of the tire, and use the wireless transmitter to send the pressure information from the inside of the tire to the first receiver module, and then display the tire pressure data. When the tire pressure is too low or flat, the system will automatically alarm.

2.Indirect TPMThe principle of working is that when the air pressure of a tire decreases, the weight of the vehicle causes the rolling radius of that wheel to become smaller, causing it to spin faster than other wheels.

By comparing the speed difference between tires, the purpose of monitoring tire pressure is achieved. The indirect tire alarm system actually relies on calculating the rolling radius of the tire to monitor the air pressure. 3.

Two types of tire pressure monitoring features: Both tire pressure monitoring devices have their own advantages and disadvantages. Direct TPMS provides even more advanced capabilities to determine the actual instantaneous pressure inside each tire at any time, making it easy to identify faulty tires. Indirect systems are relatively inexpensive, and cars already equipped with 4-wheel ABS (1 wheel speed sensor per tire) only need to upgrade the software.

However, indirect TPMS is not as accurate as a direct system, it cannot identify faulty tires at all, and the system calibration is extremely complex, and the system may not work properly in some cases, such as when the pressure of both tires on the same axle is low.

Indirect tire pressure monitoring is based on the number of tire rotations to calculate the tire pressure data, which is not accurate. The direct type is now new, and the sensor directly monitors the tire pressure data. Much more accurate than indirect.

The direct Zhigan 700 tire pressure monitoring is not bad, and the installation is very simple. This external tire pressure monitoring installation does not need to dismantle the tire, and the new product was only released in 2012.

It is still recommended to install the direct type, more accurately, I used to be the original factory is also indirect, I think it is not very convenient, I went to install the direct type, the store recommended the iron general's, now it is very good.

Most of today's cars have a tire pressure monitoring function, which is also very practical.

Indirect tire pressure monitoring is to use the wheel speed sensor to compare the speed between the tires to determine whether the tire pressure is abnormal, if the monitoring fault is found, it is likely that the wheel speed sensor has a problem or poor internal contact.

There are several reasons why the tire pressure monitoring light is on:

1. The tire pressure monitoring light is on due to the tire being punctured.

2. The tire pressure monitoring light is on, sometimes the tire pressure is too high.

3. The tire pressure monitoring light is on due to low tire pressure driving time for too long.

The indirect tire pressure monitoring device actually uses the speed sensor on the car's ABS braking system to compare the number of rotations of four tires, and if one of the tires has a low tire pressure, the number of rotations of this tire will be different from the other tires.

Using the same sensors and sensing signals as the ABS system, as long as the in-car computer makes adjustments in the software, a new function can be established in the travel computer to warn the driver that a tire and other three-change wheels are only lower than the tire pressure.

Reasons for regret of installing tire pressure monitoring:

The main reason for regretting the installation of tire pressure monitoring is that the built-in tire pressure monitoring system not only needs to be installed in the repair shop, but also due to the cumbersome disassembly and assembly steps, the labor hours required for disassembly and assembly greatly exceed the purchased equipment, and after the installation is completed, the tires of the car need to be dynamically balanced.

At the same time, it is also necessary to consider that its service life is about 5 to 8 years, and once the battery is dead, the same steps must be installed for disassembly.

Summary. Hello, indirect tire pressure monitoring is to compare the speed difference between tires through the wheel speed sensor of the car ABS system, so as to achieve the purpose of monitoring tire pressure.

Hello, indirect tire pressure monitoring is to compare the speed difference between the wheel and high tires through the wheel speed sensor of the car ABS system, so as to achieve the purpose of monitoring the tire pressure.

The indirect tire alarm system actually relies on the calculation of the tire rolling radius to monitor the air pressure. When the air pressure of a tire decreases, the weight of the vehicle will make the rolling radius of the wheel smaller, causing it to spin faster than other wheels, so that the tire pressure can be monitored by comparing the speed difference between the tires. Vehicles using indirect tire pressure monitoring devices will have two problems, one is that the vast majority of models using indirect tire pressure monitoring devices can not specifically indicate which tire pressure is insufficient; Secondly, if the pressure of all four tires is falling at the same time, then the device will fail, which is especially noticeable in winter when the temperature drops.

In addition, when the car is driving over a curve, the number of rotations of the outer wheels will be greater than the number of rotations of the inner wheels, or the tires will slip on sand or ice and snow, and the number of rotations of certain tires will be particularly high. So this method of calculating tire pressure has many limitations.