TPMS sensors transmit all kinds of data in real time, such as unique sensor ID, tire pressure, tire temperature, sensor battery status and other details. The data are sent to the engine control unit (ECU) or a specific receiver on the vehicle at ultra high frequency (UHF).
This UHF transmission of data can deliver periodic check details while the vehicle is in motion and send data continuously if the tire pressure is detected as low. Data also can be transmitted when service work is performed by using a TPMS tool to force the sensor to send data when stationary.
A TPMS tool can help decode the transmission from the sensor and display the data. This allows the technician to establish if the sensor has failed or is not fitted, whether the pressure port on the sensor is blocked, if the part is running at too high a temperature and other diagnostic information that might be included in the specific sensor data (i.e. a low battery condition on the TPMS).
The first step, before the wheel is broken down, is to use a TPMS tool to gather data on the vehicle to audit and diagnose any problems, such as a faulty or dead sensor battery, blocked pressure port or a damaged sensor. The right scan tool will help to establish whether each sensor is working or not prior to the start of the repair.
This is an important first step because, by law, the moment the wheel is off the vehicle and broken down, the responsibility for fixing the TPMS issue passes to the tire dealer. Without an audit trail of TMPS sensor function on the vehicle record before work begins, customers may blame the sensor malfunction on the dealer and refuse to pay. A pre-work inspection is important to limit your liability for any problems that may occur.
Be sure to follow the vehicle owner’s manual and specific service recommendations for the TPMS replacement process.
Finally, once the technician is finished with the TPMS replacement, it’s a good idea to do a final test and print out the results for the customer.
Not only does this protect from liability by showing the job has been completed professionally, it also affirms your reputation for quality. Remember to use the TPMS scan tool to deactivate or turn off the TPMS warning light as necessary.