TPMS Sensors

Tire pressure monitoring has been required on light vehicles sold in the United States since the 2008 model year, which means if you are building a second set of wheels for a modern vehicle, you need a second set of sensors or you will drive with a permanent dash light.There are two system types. Direct TPMS uses a battery-powered sensor inside each wheel that measures actual pressure and radios it to the vehicle. Indirect TPMS uses the ABS wheel speed sensors to infer that a tire is low because it is rolling at a slightly different rate, and needs no hardware in the wheel at all. If your vehicle displays individual tire pressures, you have direct TPMS.For direct systems you can buy OE sensors matched to your vehicle, or programmable universal sensors that a shop clones to your vehicle protocol with a TPMS tool. Programmable sensors are usually cheaper and cover far more applications from one part number. Either way the vehicle needs a relearn procedure after installation so it knows which sensor is at which corner. Some vehicles relearn automatically after driving, some need a specific key and pedal sequence, and some need a scan tool.Sensor batteries are not serviceable and typically last 5 to 10 years, so if you are mounting new tires on wheels with older sensors it is usually worth replacing them while the tire is off.