| Pin Number |
Description (may be empty) | |
| 1 | GND | Ground |
| 3 | Self-diagnostic button (if equipped) | |
| 2 | K-Line | benzine engine diagnostic (CFI, KE) and DM |
| 4 | K-Line | diesel engine diagnostic (EDS, ARA) or self-diagnostic LED (if present) |
| 5 | K-Line | ASD, 4MATIC diagnostic |
| 6 | K-Line | safety devices: Airbag, SRS, AB diagnostic. Service interval reset. |
| 7 | K-Line | air-conditioner and heater (Tempmatic, Automatic) diagnostic |
| 8 | K-Line | Engine and ignition diagnostic |

