[mothered]

I assume you've either exploited a vulnerability to allow access to the target device without permission, or you've established a connection as a trusted device/pairing thereby allowing the exchange of data between both devices.

Would this be correct?

How would one gain access to a android phone if bluetooth is on

Hence my aforementioned post- questioning whether you've already established a connection with the target device.

Given you haven't accessed the device, your question more so relates to how to compromise the phone's Bluetooth, and not anything (at this stage) In hacking the phone per se. The methods used to compromise a Bluetooth connection are quite In depth and as such, beyond the scope of this post.