| Pin | Signal | Description |
|---|---|---|
| 1 | CAR_MIC_IN | Car microphone input |
| 2 | GND / SENSE | Ground / chassis |
| 3 | CAR_AUDIO_R | Car audio right output |
| 4 | CAR_AUDIO_L | Car audio left output |
| 5 | ANALOG GND | |
| 6 | RS232_DCD | |
| 7 | RS232_CTS | |
| 8 | RS232_TXD | |
| 9 | RS232_RTS | |
| 10 | RS232_RXD | |
| 11 | RS232_DTR | |
| 12 | IN_CALL | |
| 13 | USB_VDD | USB voltage detection |
| 14 | UDC+ | USB data positive voltage |
| 15 | UDC- | USB data ground/negative |
| 16,17,18 | GND | |
| 19 | CAR_ON# | |
| 20,21,22 | V_ADP | +5 volts DC to charge/power the unit |

