D3400 cannot turn on Bluetooth. Camera says cannot due to current settings/

It sounds like you are having an issue with the Bluetooth icon not appearing on your NHDT W57 head unit in your Toyota Vanguard SUV. This could be due to a few different issues.
First, make sure that your head unit is actually capable of Bluetooth connectivity. Some head units may not have this feature built-in.
Second, check to see if the Bluetooth feature is turned on in the head unit's settings. If it's turned off, you will not see the Bluetooth icon.
Third, ensure that your phone's Bluetooth is turned on, and that it is in pairing mode. Once your phone is paired with the head unit, the Bluetooth icon should appear.
Fourth, check the firmware version of your head unit and update it if necessary. Some older version may have bugs or compatibility issues with current devices.
If none of these steps help, it could be a hardware issue and it would be best to consult with a professional or contact the manufacturer for assistance.

please re set the camera in the menu

No. Bluetooth is different than WiFi just as NFC(near field communication) is different from the first two. All radio spectrum but different frequencies.

Yes if you download the app.

From this forum:
https://www.nikonforums.com/forums/topic/7492-bluetooth-this-option-is-not-available-at-current-settings-or-in-the-cameras-current-state/

I had this exact problem with my new d3400 as well. My settings originally showed Bluetooth ON and when I clicked on it, it showed a couple options: Network Connection-ON, Paired Devices, Send while off-"ON". I clicked on Paired Devices and it showed that it had connected to my phone today (even though my connection to snapbridge was unsuccessful) - so in an effort to retry my snapbridge connection I deleted my phone from the paired devices and this caused the Bluetooth on the camera to completely turn OFF and grey out. Same problem everyone here seems to be having where I couldn't even re-enable the bluetooth again and just saw an error message saying "option unavailable in current setting".
Alas, I found a solution - I have an iPhone 6 so for me at least this worked:
I went to bluetooth settings on my phone and went to the camera name and said "forget this device". I then deleted the snapbridge app and redownloaded it.
Then I went on the camera and tried to do the "connect to smart device". Instead of going to snapbridge, I went to my phone's bluetooth settings and chose the camera once the name popped up again. It prompted a pair message and I had to confirm the # on the camera matched the # on my phone. It then paired successfully and the bluetooth on my camera was back on! -- (disclaimer.. while this was great to see that at least the bluetooth was on again, this did not resolve the issues I was having with snapbridge - I still can't seem to get it to connect through the app, but perhaps it will work out for others..)

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Download to this link your Kodak D3400 driver http://www.nodevice.com/driver/DC3400/get30556.html or http://download.cnet.com/Kodak-DC3400-Digital-Camera/3000-18489_4-63527.html

hi there!, about your problem make sure that you visibility is shown to all, remote sim mode if OFF and well yeah the bluetooth is on xD

Go to the start menu, and select Settings. Select Connections from the bottom tabs and find the Bluetooth icon, and click on the bluetooth icon. Select Mode from the bottom tabs and check box that says "turn bluettoth on"