What is TPMS?

May 16th, 2012

Here at OriginalWheels.com we get asked all the time by customers, “What does TPMS mean?” or “What is TPMS?” TPMS quite literally means Tire Pressure Monitoring System; and if your car was made in the last 5, years it definitely has it. You may have just not realized what it was.

There are two different types of TPMS systems, direct and indirect. A direct TPMS system has a sensor actually attached to the wheel or valve stem that takes pressure readings. An indirect TPMS system works with your anti-lock brake system to count rotations per mile of each wheel compared to the others. The biggest problem with indirect is that it is not terribly accurate and will not indicate low pressure if all the tires are losing pressure equally.

What does TPMS do?

In a direct TPMS system, the sensor detects if the tire pressure on any of your tires goes 25% or more below its recommended level. If that happens, it sends a signal to your car’s computer, switching on a dashboard warning light. There is usually a general warning light and a diagram that shows specifically what tire the warning light is talking about. This is to alert the driver that a tire has low pressure and needs to be checked.

Why TPMS is Important

The reason why it’s so important to know if your tire pressure is low is because it can help you avoid major accidents. It puts a lot of stress on a tire when it is driven with incorrect pressure, and it  could cause the tire to fail while driving at high speeds. Under-inflated will also increase the distance it would take you to stop in the case of an emergency, especially on a wet road.

Having your tires at a proper pressure will also save you money. Properly inflated tires wear more evenly and will last longer. You will also get slightly better gas mileage with tires at the proper PSI, and over time that could make a big difference!

Do I  Ever Have To Buy New TPMS?

The short answer is yes.
They do have a battery built into them, which will eventually die and have to be replaced. On most systems, you cannot just replace the battery; you’d usually have to replace the whole device. But on the upside, the batteries will usually last for years, and the devices are not prone to damage. Here at OriginalWheels.com, we get many customers who ask if they have to replace their TPMS when they purchase something like a late model Kia rim. Generally your old TPMS will still work just fine… unless you just got incredibly unlucky and hit it just right.

Where Can I Get TPMS Sensors, and Can I Install Them Myself?

There are many used parts shops that sell used sensors. Keep in mind they have a limited life, so getting them used may not last as long as a new one. If you’re lucky and enjoy picking through junkyards you might be able to find a good one still attached to a scrapped wheel. The most common option though is to just order it through your local dealer, but it may cost you anything from $50 to $275 per sensor.

You will need to bring the sensors to your local tire shop for installation and programming. Although you may be able to install it onto the wheel yourself, you need a special device to sync and program the sensor for your specific vehicle and tire pressure. They have to be specially programmed to avoid vehicles getting confused by other people’s sensors.


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