How To Inspect A Tire Pressure Monitoring Sensor And Valve Stem

    Published: 06-16-2009
    Views: 13,734
    Tyson Boyer with Dill Air Controls discusses how to properly inspect a tire pressure monitoring sensor and valve stem.

    Tyson Boyer: Hi! I am Tyson Boyer with Dill Air Controls. Today I'm showing you how to inspect the tire pressure monitoring sensor and valve stem. Many of the cars in your bay today have a tire pressure monitoring system. During your initial inspection you need to be sure you're following the three simple steps in order to identify potential problem before you start servicing the car.

    The first step is to start the vehicle and look for a flashing or solid light on the dashboard. If the light flashes this indicates the system malfunction, which most likely means a sensor battery is dead or the sensor is damaged. If the light comes on solid one or more tires are under inflated.

    The light is design to come on if the tire pressure is 25% or more below the driver door placard value. The second step is to take your TPMS scan tool and scan all four sensors to ensure they activate. By scanning the sensors, you can verify this before performing work on the vehicle.

    Beware, in some situations a vehicle that is driven at low speed for a very short distance may not have recognized that a sensor is not functioning properly. Some vehicles have a four size spare with the sensor. If the TPMS light is flashing and you properly read the four sensors in the wheels, you may also need to check to be sure the sensor in the spare is functioning.

    The third step consists of performing a visual inspection around the valve stem. Is there corrosion built up around the valve, hex nut, valve cap or valve core, is the aluminum valve stem bent or is the valve cap, a metal one that is not removable of two fingers? Galvanic corrosion may have occurred, season the cap to the stamp. If this occurs stop immediately and notify the customer. Most metal valve caps are not TPMS compatible, because the material in the cap causes galvanic corrosion when in contact with the aluminum valve stem.

    After the valve cap is removed visually inspect the valve core for any noticeable signs of corrosion or salt build up. If you see a potential problem, stop and notify the customer immediately. Note. If you're removing the tire from the wheel for repair or replacement it is highly recommended by the Rubber Manufactures Association, to change the service kit when the vehicle is equipped with a tire pressure monitoring stems and sensor.

    The rubber sealing grommet deteriorates overtime much like the rubber in traditional valve stems and then tires. This is one reason why we replace the service kit components and that's how to inspect the tire pressure monitoring sensor and valve stem.