| Pin Number |
Description (may be empty) | |
| 1 | GND | Ground |
| 2 | Self-diagnostic button (if present) | |
| 3 | 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 | benzine engine diagnostic (HFM-SFI, DI) |
| 9 | K-Line | ADS diagnostic |
| 10 | Engine speed sense (gasoline engine). K-Line for RST (R129), CST (W124) | |
| 11 | K-Line | Anti-thieft (ATA) diagnostic |
| 12 | K-Line | IRCL diagnostic |
| 13 | K-Line | Transmission Control Unit diagnostic (EGS, EATC) |
| 14 | K-Line | Engine (ESCM, MAS) diagnostic, ISC, EA, EFP diagnostic, cruise-control (CC) diagnostic |
| 16 | +12v | Power |
