inCarDoc Download link: inCarDoc - OBD2 ELM327 Scanner - Google Play 

Step1:
Open your phone's Bluetooth Settings, search for and tap "vLinker FD".





Step2:
A request pairing prompt will be generated when pairing, enter the pairing code "1234" and click "OK".





Step3:
Successfully paired to the Bluetooth device "vLinker FD".





Step4:
Open the app and click on "Settings". 





Step5:
Click on "Connection".





Step6:
Click on "Connection mode".





Step7:
Select "Bluetooth" as the connection mode. 





Step8:
Click on "BT connection".





Step9:
Select the paired Bluetooth device "vLinker FD".





Step10:
Return to the home page when the settings are complete.





Step11:
Click on "Connect <BT"vLinker FD">





Step12:
Connected successfully.