Terminal assignment at Data Link Connector (DLC)
- Terminal 4: Ground connection for VAG 1551 Scan Tool
- Terminal 16: Voltage supply for VAG 1551 Scan Tool
- Terminal 7: K wire (data line between Scan Tool and the various vehicle systems with On Board Diagnostic (OBD) capability)
NOTE:
- The harness connection of the DLC runs through a welded point in the wiring harness to the various control modules (See SYSTEM WIRING DIAGRAMS ).
- The DLC is connected to connector C terminal 24 of the A/C control head -E87-.
- If the readout "Error in communication link" appears on the tester when starting or during OBD:
- Unplug all the connectors to the control modules of other vehicle systems with OBD one after the other.
- Each time after unplugging the connector to a vehicle system, once again enter address word 08 (AC/Heating) in operating mode 01 (Rapid data transfer)
- If the control module identification is then displayed, replace the control module which was last unplugged from the diagnostic cable.