How does a car's tire pressure monitoring system function?

@kaylie 

A car's tire pressure monitoring system (TPMS) functions by using sensors to measure the air pressure in each tire. There are two types of TPMS: indirect and direct.

1. Indirect TPMS: This system uses the wheel speed sensors of the anti-lock braking system (ABS) to estimate tire pressure. It compares the rotational speeds of all four tires. If one tire has significantly different rotation speed from the others, it assumes that the tire's pressure is low. The system then alerts the driver through a warning light on the dashboard.
2. Direct TPMS: This system uses individual pressure sensors mounted on each tire's valve stem or inside the tire assembly. These sensors directly measure the air pressure in each tire and transmit the information wirelessly to the car's onboard computer system. If any tire's pressure drops below a predetermined threshold, the system sends a warning message to the driver, typically through a dashboard light or display.

Regardless of the type of TPMS, if the system detects low tire pressure or a significant pressure difference between tires, it notifies the driver to take action. This allows drivers to monitor tire pressure more accurately, enhancing safety and fuel efficiency while also reducing tire wear and the risk of blowouts.

@kaylie 

A car's tire pressure monitoring system (TPMS) functions through the use of several components and sensors. The main purpose of TPMS is to alert the driver if the tire pressure in any of the car's tires becomes too low.

There are two types of TPMS: direct TPMS and indirect TPMS.

1. Direct TPMS: This system uses pressure sensors located inside the tires, typically mounted on the valve stem or attached to the inner lining of the wheel. These sensors constantly monitor the tire pressure and send real-time data to the car's onboard computer. If the tire pressure drops below a specific threshold determined by the manufacturer, the system triggers a warning indicator on the dashboard, alerting the driver to check the tire pressure.
2. Indirect TPMS: This system measures the rotational speed of the tires using the car's anti-lock braking system (ABS) sensors. The ABS sensors detect variations in wheel speed caused by changes in tire diameter due to low tire pressure. If one tire rotates at a different speed compared to the others, the system recognizes it as an underinflated tire and triggers a warning light on the dashboard.

In both cases, once the tire pressure is restored to the recommended level, the TPMS will typically reset itself automatically.

It is important to note that TPMS is a safety feature, as it helps maintain proper tire pressure, improves fuel efficiency, enhances vehicle stability, and reduces the risk of accidents caused by improper tire inflation.