The purpose of the tire pressure monitoring system (TPMS) in your vehicle is to alert you that at least one or more tires are significantly under-inflated and create potentially unsafe driving conditions.
Not every TPMS works the same way. The low tire pressure indicator represents the final step in the process of either an indirect TPMS or a direct TPMS.
Direct TPMS uses a sensor mounted in the wheel to measure the air pressure in each tire. When the air pressure drops 25% below the manufacturer’s recommended level, the sensor transmits that information to your car’s computer system and triggers your dashboard indicator light.
Indirect TPMS works with your car’s Antilock Braking System’s (ABS) wheel speed sensors. If a tire’s pressure is low, it will roll at a different wheel speed than the other tires. This information is detected by your car’s computer system, which triggers the dashboard indicator light.
Many situations can cause a TPMS warning light to turn on or blink. Some TPMS problems include:
If the TPMS sensor is not functioning or reading accurately, the natural assumption is that the sensor is the problem and that replacing it will fix the issue. Usually it will. But until you check the rest of the TPMS system, there is no guarantee that a bad sensor is the only problem affecting the operation of the system.
Do not use the TPMS warning light as a substitute for regularly checking your tire pressure and keeping it at the recommended level. That is not its purpose. Think of TPMS as a safety/emergency warning system – not as a replacement for your own tire pressure monitoring practices.
Tires are fundamental to your vehicle's performance and safety, and maintaining proper tire pressure is fundamental to tire performance. Therefore, the TPMS warning light should never be ignored. If one or more of your tires are under-inflated, it can:
Remember, your TPMS light performs an important and under-appreciated role by making your car more safe, efficient, and environmentally friendly.