| Number | X-pin, colour | Description | 
|---|---|---|
| X1448 | 26-pin, Black | Plug connector Air suspension control unit | 
| Pin | Type | Description / Signal type | Connection / Measuring notes  | 
|---|---|---|---|
| 1 | E | Sensor signal | Rear left level sensor | 
| 2 | E | Sensor signal | Rear right level sensor | 
| 3 | Not used | ||
| 4 | Not used | ||
| 5 | M | Sensor ground | Rear right level sensor | 
| 6 | M | Control unit ground | Ground point | 
| 7 | A | Sensor positive supply | Rear right level sensor | 
| 8 | Not used | ||
| 9 | Not used | ||
| 10 | E | Signal, switch off consumer load | General module | 
| 11 | A | Signal Rear left valve | Rear left valve | 
| 12 | A | Signal Relay, compressor pump control | Relay, compressor pump control | 
| 13 | A | Signal Valve, down | Valve, down | 
| 14 | Not used | ||
| 15 | E/A | K-bus signal line | K-bus connector | 
| 16 | Not used | ||
| 17 | Not used | ||
| 18 | M | Sensor ground | Rear left level sensor | 
| 19 | Not used | ||
| 20 | A | Sensor positive supply | Rear left level sensor | 
| 21 | Not used | ||
| 22 | E | Terminal 30 | Fuse F50 | 
| 23 | Not used | ||
| 24 | Not used | ||
| 25 | Not used | ||
| 26 | A | Signal Rear right valve | Rear right valve |