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I am looking for the files that correspond to the recorded fingerprints on my Nexus 6P and a way to "reset" the fingerprint system. Something similar to how Android stores lock screen settings (pattern etc.) under /data/system/locksettings.db*, and you can remove the lock screen by deleting these files (if you have root access).

The reason I am asking is because after a TWRP restore on a new Nexus 6P, my fingerprint hardware is not working anymore. The error message is Fingerprint hardware not available. Also see this question: "Fingerprint hardware not available" after TWRP restore

All five previously recorded fingerprints show up on the settings UI, but I am not able to delete them by clicking "Delete".

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try removing these files also

/data/system/users/0/fpdata/user.db
/data/system/users/0/settings_fingerprint.xml

Instead of removing files, appending the filenames with some random extension would be better. So, if anything goes wrong we can revert the changes.
eg: user.db -> user.db.xyz or xyx_user.db

I faced the same error too and this worked for me.

  • That's one step closer! Thanks @lazykiller. Removing the files got rid of the "Fingerprint hardware not available" error message. However, when I try to set up new fingerprints in Settings now, I am getting this error "Enrollment was not completed". In logcat I'm seeing fpc_tac_send_cmd failed with retval: -3, do_enroll failed -5, and onError(1) from fingerprintd. Any ideas? Thanks. – friederbluemle Apr 27 '17 at 19:58
  • This worked for me (after messing with the other files in /data/system) – pjv Jul 9 at 19:04
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Secure location

Capturing and recognizing your fingerprint must happen in a secure part of the hardware known as a Trusted Execution Environment (TEE).

Hardware access must be limited to the TEE and protected by an SELinux policy.

Fingerprint data must be secured within sensor hardware or trusted memory so that images of your fingerprint aren't accessible.

Source: https://support.google.com/nexus/answer/6300638?hl=en

Click on Fingerprint hardware security requirements to get to the information, it's the last bullet point

  • That's useful information. Thank you. But then the real question is: My backed up and restored ROM shows the fingerprints on the UI. Where does the Android system get this information from and why does it still think 5 fingerprints are stored? Obviously the real fingerprint data is locked inside my old, bricked 6P. I just need a way to reset the fingerprints on my new phone. – friederbluemle Jan 24 '17 at 19:34

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