| Pin | Name | Direction | Color | Description |
| 1 | Vin | | | Charger input |
| 2 | GND | | | Charger ground |
| 3 | ACI | | | Accessory Control Interface (short with pin 2 for handsfree recognition) |
| 4 | V Out | | | Connected to pin 3 in DKU-2 usb data cable |
| 5 | USB Vbus | | | Also act as USB power detection? Should be connected to USB pin 1 in usb data cable. |
| 6 | FBus Rx/USB D+ | | | USB exists only in some models*. Should be connected to USB pin 3 in usb data cable. |
| 7 | FBus Tx/USB D- | | | USB exists only in some models*. Should be connected to USB pin 2 in usb data cable. |
| 8 | GND | | | Data GND |
| 9 | X Mic- | | | Audio in - Ext. Mic input negativ |
| 10 | X Mic+ | | | Audio in - Ext. Mic input positiv |
| 11 | HS Ear L- | | | Audio out - Ext. Audio out - left, negativ |
| 12 | HS Ear L+ | | | Audio out - Ext. Audio out - left, positiv |
| 13 | HS Ear R- | | | Audio out - Ext. audio out - right, negativ |
| 14 | HS Ear R+ | | | Audio out - Ext. audio out - right, positiv. Pins 10-14 may be used for antenna connection. |
| 15 | GND | | | shield GND in cavities |