| Number | X-pin, colour | Description | 
|---|---|---|
| X53 | 9 -pin, Black | Plug connector Auxiliary fan stage 2 relay | 
| Pin | Type | Description / Signal type | Connection / Measuring notes | 
|---|---|---|---|
| 1 | Not used | ||
| 2 | A | Activation Auxiliary fan stage 2 | Fuse F78 1994_9 Auxiliary fan motor 1995_9 | 
| 3 | Not used | ||
| 4 | A | Signal High pressure switch | Connector, auxiliary fan stage 2 1994_9 High pressure switch 1995_9 | 
| 5 | Not used | ||
| 6 | E | Voltage supply terminal 30 | Fuse F106 1994_9 Fuse F34 1995_9 | 
| 7 | Not used | ||
| 8 | E | Voltage supply, terminal 15 | Fuse F38 1994_9 Fuse F20 1995_9 | 
| 9 | Not used | ||