How to Service Tire Pressure Monitoring System
Since 2008, all vehicles have been required to have tire pressure monitoring systems that detect when tire pressure falls 25 percent below the recommended levels, alerting the driver through a dashboard low tire pressure warning light. To check if your vehicle is equipped with TPMS, look for a low tire pressure warning light to come on when the key is turned on in the ignition – if the light is on, it means your vehicle is comes with the tire pressure monitoring system.
Tire pressure monitoring system needs maintenance to keep working properly. Let us take a closer look at what affects TPMS and what service the tire pressure monitoring system needs.
Tire pressure monitoring systems include tire pressure sensors that are mounted on the wheels or on tire valve stems. Direct TPMS sensors monitor air pressure in each tire, showing the actual pressure in each tire and displaying which tire is low on air on a dashboard screen. Indirect TPMS uses antilock brake sensors to detect wheel speed and warn of low tire pressure based on tire revolutions, but without showing specifically which tire is underinflated.
If your tire pressure monitoring system warning light stays illuminated it means your tire pressure is low. If your TPMS warning light is flashing it means tire pressure sensors or other parts of the system malfunction and need maintenance or repair. Checking your owner manual may also help determine what it means.
Tire pressure sensors can be damaged by potholes, dirt and road debris. Sensor batteries may expire over time. Sometimes tire pressure monitoring system can malfunction when radio signals transmitted by tire pressure sensors to the control unit are blocked by other radio signals on the same frequency. If your tire pressure monitoring system is malfunctioning, you should get it serviced right away to avoid underinflated tires that can lead to poor fuel economy, faster tire wear and tire damage.
Some of the TPMS services offered by tire shops include:
- Checking all tire pressure sensors and their assembly to verify their accurate transmission of data to your vehicle's computer system
- Testing batteries in all tire pressure sensors
- Removal of old tire pressure sensors
- Proper installation of new sensors, including replacement of the valve core, cap, nut, and o-ring (seal) before remounting the tires
- Using a specialized TPMS tool to reset tire pressure sensors
Most tire shops recommend servicing the TPMS when changing or installing new tires or wheels. Servicing tires with direct TPMS will cost more as it requires extra parts and labor replacing the valve core, retaining nut, seal and cap on the valve stem, then testing the system to make sure it is operating properly. Most of the time TPMS needs to be electronically reset after servicing, but sometimes driving few miles automatically resets the system as long as the sensors are functioning properly.
Always let the service center personnel know if your vehicle is equipped with TPMS, direct or indirect, and if you have added aftermarket tire pressure monitoring system to avoid damaging TPMS during bead loosening and tire dismounting.
For a direct TPMS system, the air pressure should be released from the tire, and the aluminum tire valve with attached tire pressure sensor should be unbolted and gently dropped into the still-mounted tire and wheel to protect the sensor from being broken during bead loosening and tire dismounting.
The original TPMS aluminum sensors should be fitted with a new rubber, nickel-plated valve core and aluminum retaining nut. Make sure to retain the original aluminum TPMS sensor's type valve cap. Rubber snap-in valve based TPMS sensor should be replaced with new rubber snap-in valve designed to accept a TPMS sensor to avoid possible air leaks. All components must be torqued to appropriate specifications to prevent air leaks.
Keep in mind that some tire manufacturers recommend against using sealant kits to repair flat tires because the sealant could damage the TPMS sensors.