| Number | X-pin, colour | Description |
|---|---|---|
| X1544 | 9 -pin, Black | Plug connector Air pump relay |
| Pin | Type | Description / Signal type | Connection / Measuring notes |
|---|---|---|---|
| 1 | Not used | ||
| 2 | E | Voltage supply terminal 30 | Fuse F107 |
| 3 | Not used | ||
| 4 | A | Signal Air pump relay | Engine control module II (DME) |
| 5 | Not used | ||
| 6 | A | Series resistor, secondary air pump | Connector, air pump |
| 7 | Not used | ||
| 8 | E | Voltage supply terminal 30 | Fuse F17 |
| 9 | Not used | ||