| Number | X-pin, colour | Description |
|---|---|---|
| X51 | 9-pin, black | Plug connector Relay, A/C compressor |
| Pin | Type | Description / Signal type | Connection / Measuring notes |
|---|---|---|---|
| 1 | Not used | ||
| 2 | E | Terminal 30 | Fuse F63 |
| 3 | Not used | ||
| 4 | E | Terminal 15 | Fuse F28 |
| 5 | A | Voltage supply | Heating and A/C control module |
| 6 | A | Auxiliary fan stage 2 via relay | Solenoid clutch |
| 7 | Not used | ||
| 8 | A | Compressor enable from DME | Digital motor electronics control unit Digital diesel electronics control unit |
| 9 | Not used | ||