Some older car models you still may need to manually enter the VIN #. Some cars the TPMS function is incorporated into another module that is not identified as TPMS module. Some cars don't have true TPMS sensors but work off ABS sensor wheel speed variation that will set a tire pressure warning lamp. If car has TPMS sensors, you should have a TPMS tool like a TS401 to activate and read the TPMS sensors.