TPMS Sensor

What is tpms?

A tire pressure monitoring system (TPMS) is an integrated car tire pressure monitoring system that continuously monitors tire pressure. There are two types of TPMS systems:

• direct systems (where the pressure sensor is placed inside the rim and can measure accurate tire pressure)
• Indirect systems (where the relative pressure drop is detected via the existing ABS sensor). In the event of a pressure drop in one or more tires, the driver is notified via the dashboard.

If your car is equipped with a TPMS system, you need to determine whether it is a direct or indirect system. If you are skilled enough to navigate your car's dashboard menu, there is also a general trick to identify the system. With a direct system, you will almost always be able to read the exact tire pressure from the TPMS menu on the dashboard. If this is not the case, but you can find the tire pressure menu, you probably have an indirect system .

• With an indirect TPMS system, you don't have to consider TPMS when buying new wheels; changing wheels doesn't affect the TPMS system.
• If your car has a direct TPMS system, you will need to consider TPMS when purchasing rims as the sensors must be mounted on the rims. It is important that the rims you choose are compatible with TPMS sensors.

How does a direct TPMS system work?

In a direct system, a sensor mounted inside the rim measures the tire pressure. This information is sent via radio to a control unit in the front of the car. The way this information is presented varies depending on the car model. Often, the exact tire pressure can be read in real time on the dashboard, but some systems only give a warning if the tire pressure is too low.
How does an indirect TPMS system work? In an indirect TPMS system, the ABS or ESP sensor measures the rotational speed of each wheel. In the event of a pressure drop (flat tire), the rotational speed changes and a message appears on the dashboard. The vibration of the tires is also measured; a change in this also indicates a pressure drop.
What are the advantages and disadvantages of these systems? A direct TPMS system is very accurate because it is based on measuring the exact pressure of each tire. In addition, the system also works when the car is stationary and can also measure the pressure of the spare tire in the trunk. The downside is that the system is more expensive due to the TPMS sensors required. These need to be replaced periodically when the battery runs low, and if your car has multiple wheels (such as a summer set and a winter set), all wheels must be equipped with a working sensor. An indirect TPMS system is somewhat less accurate; for example, it cannot measure the actual tire pressure or tire temperature. Perhaps the most important difference is that an indirect system does not work when the vehicle is stationary. If you get a flat tire and get into a parked car, you will not receive a warning immediately after leaving the car. Its advantage is that the system is simpler and cheaper in terms of maintenance and changing tires or rims, since it does not involve TPMS sensors.

Buy the right TPMS sensor for your car here!