How to Stop My iPhone From Turning on Bluetooth by Itself
Bluetooth support is one of the standard features on the Apple iPhone. This feature allows you to exchange data from mobile devices over a wireless network. When this feature is enabled, it may drain the battery, causing your iPhone to die. Occasionally, the feature may become enabled by itself. Disable the Bluetooth feature to prevent it from turning on by itself again.
Press the "Home" button on the front of the iPhone.
Slide the switch next to "Bluetooth" to the "Off" position.
Press and hold the "Sleep/Wake" button at the top of the iPhone to power off the phone. Slide the switch that is labeled "Slide to power off."
Press and hold the 'Sleep/Wake" button to power on the iPhone.