Should You Replace TPMS Sensors When You Replace Tires? – Jalopnik

A tire pressure monitoring system (TPMS) is an automotive part that keeps you informed when tire pressure drops or rises to unsafe levels. The system works by comparing each tire to a programmed pressure threshold, and when the value falls below that limit (usually about 25% below spec, according to NHTSA guidelines), the warning light comes on.

A TPMS warning is not automatically a sign of sensor failure. In fact, most TPMS lights will go out once all four tires (plus the spare tire, if checked) are inflated to the recommended psi. A more reliable sign of a bad sensor is when the light remains on despite proper pressure. However, some cars require a relearning procedure to reset the TPMS warning light after replacing the sensors or rotating the tires, and certain vehicle brands require a specialized activation tool to complete the relearning process.

Should You Replace TPMS Sensors When Installing New Tires? The short answer is no, unless someone actually fails. Replacing tires alone is not a reason to replace sensors, and there is no point in replacing a set of functional units. What needs to be replaced are broken sensors or sensors with dead batteries. And even then, you only replace the individual damaged sensors, not the entire set. A reputable shop will check each sensor’s pressure reading and battery status during a tire repair or tire rotation.

There are two types of TPMS. Direct TPMS have been used in modern automobiles since 2007, in accordance with the Transportation Recall Enhancement, Accountability, and Documentation (TREAD) Act. Direct TPMS work using a real sensor that measures the pressure in the wheel. It is usually built directly into the valve stem or attached to a band tied around the wheel. This system is more accurate, but more expensive to maintain. The disadvantage of direct TPMS is that the sensors are at greater risk of damage during a tire job, especially the tire type.

Older cars use TPMS indirectly, which works by reading wheel speed data from the anti-lock braking system (ABS). Indirect TPMS are cheaper and require less maintenance, but these systems are not nearly as accurate or reliable as direct TPMS. Indirect systems can fail if a wheel speed sensor wire is damaged during a braking job or other form of maintenance. They may also need to be reset after changing the tire or inflating the tire.

A good TPMS is one of the systems in your car that actively protects you by warning you before it becomes dangerous. Take action and inflate your tires when the system gives you that warning. When your tires are a few PSI low, it can affect the car’s braking and handling, and increases your risk of a blowout. Experiencing a blowout on the highway or a flat tire in the middle of nowhere is never a good feeling. Fortunately, a reliable tire pressure monitoring system can be your lifesaver (or your predictor) before an unpleasant setback occurs.