There is provided a vehicle abnormality detection method detecting an abnormal state in which a high temperature occurs due to maladjustment of a vehicle bearing mechanism section or vehicle brake mechanism section, and a device thereof and a sensor unit thereof. By use of the sensor unit 100 mounted in a rim 31, an air temperature within a tire 2 is sensed as a first temperature and a temperature (second temperature) of the rim 31 is sensed as a temperature related to at least one of a temperature of the vehicle bearing mechanism section and a temperature of the vehicle brake mechanism section 40. Then a temperature difference between the first and second temperatures is calculated and when the temperature difference is a predetermined value or more, it is determined that an abnormality has occurred in the vehicle bearing mechanism section or vehicle brake mechanism section 40. The abnormality is thus detected.