| Number | X-pin, colour | Description | 
|---|---|---|
| X18180 | 3-pin, black | Plug connector CD changer | 
| X18729 | 6-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 F56 | 
| 3 | E/A | I-bus signal line | I-bus connector | 
| Pin | Type | Description / Signal type | Connection / Measuring notes  | 
|---|---|---|---|
| 1 | E | Positive signal, low frequency left | Radio | 
| 2 | A | Negative signal, low frequency | Radio | 
| 3 | M | Shield | Audio shield | 
| 4 | E | Positive signal, low frequency right | Radio | 
| 5 | Not used | ||
| 6 | Not used | ||