I am excited to share my findings with you guys, and finally, ELM 327 mini cheaper Bluetooth worked with Vitz (tried v1.5 and v2.1 both worked like a charm) and I am sure it will work for almost all cars, the problem is not with the device but the app that is unable to read the ECU due to bad protocol selection.
So here is the solution,
1- First of all you need to check the supported protocol from the following link:
Mine is Vitz 1.0 F so compatible protocol should be TOYOTA CAN instead ISO 15765-4 CAN.
2-Download the FREE app OBD Driver or ELMScan Toyota
I recommended using first one OBD Driver that's one that allows you to manually select the supported protocol.
I hope this will help.