| Number | X-pin, colour | Description |
|---|---|---|
| X18180 | 3-pin, black | Plug connector CD changer |
| X18729 | 4-pin, black | Plug connector CD changer |
| Pin | Type | Description / Signal type | Connection / Measuring notes |
|---|---|---|---|
| 1 | M | Ground | Ground point |
| 2 | E | Voltage supply terminal 30 | Fuse F75 |
| 3 | E/A | I-bus signal line | I-bus connector |
| Pin | Type | Description / Signal type | Connection / Measuring notes |
|---|---|---|---|
| 1 | A | Positive signal, low frequency left | Radio |
| 2 | M | Negative signal, low frequency left | Radio |
| 3 | Not used | ||
| 4 | A | Positive signal, low frequency right | Radio |