The indirect measurement TPMS system of this car has misdetected low tire pressure on three occasions. Most recently, on October 3 while driving on the freeway at about 70 MPH the TPMS alert illuminated. I checked the information screen and the display showed low pressure in all four tires. Because I have had misdetection of the right front tire twice before, and that it seemed very unlikely that all four tires would deflate at the same time, I disregarded the alert as a false detection. Later I checked the air pressure in all four tires and found it to be exactly correct. In an earlier episode, as I mentioned the TPMS alerted that the right front tire was low. In this instance, I did not have a history of false detections, so I believed the information to be accurate and immediately exited the freeway and returned home where I had a (very accurate) tire pressure gauge. Of course, the pressure was correct in all tires. I then followed the Volvo recalibration procedure and this completed successfully until later that day when the same tire alerted to low pressure again. I rechecked, again pressure was correct, and re-ran the calibration procedure. I did not have any other false detection again until about a year later when the October 3 incident occurred. The car has had at least one -??total system update-?? to the software to address other issues since the first false detection incident, possibly two (not sure). The problem I am having with this is that Volvo apparently decided to change from direct sensor measurement to indirect wheel speed measurement around 2019 or 2020 as a cost saving measure. That is fine, but the indirect measurement system they are using is causing so many false alarms that now the first thing I think when I see an alert is that it is not a real problem. This is not a good situation. Volvo forums are full of complaints by other owners of similar false alarms. Volvo should fix this problem through software or restore direct measurement.

- Rancho Santa Margarita, CA, USA