Sony Ericsson Hands Free devices connect to cell phones using a technology called "Bluetooth." This enables you to engage in phone conversations without being forced to hold anything. For situations like driving or carrying something, this can be beneficial. If you want to connect your Sony Ericsson Hands Free device to your cellular telephone, you'll have to pair the two devices together.
Use the "Settings" menu on your cell phone to turn on the device's Bluetooth capabilities (if they aren't already on).
Press down on the "Power" button on your Sony Ericsson Hands Free device. Continue to hold this down for five seconds. A "Pairing" icon will appear on the device's main display.
Select your Sony Ericsson Hands Free device from the menu of found devices on your cell phone.
Enter "0000" on your cell phone's keypad. This is the default Bluetooth password for your Sony Ericsson Hands Free device. Once you do this, the two devices will be successfully connected together using Bluetooth.