Diagnostic Signal

The Diagnostic Signal is connected to pin 55 of the Motronic control module, the signal is bidirectional (PIN 55 - INPUT + OUTPUT).

The diagnostic signal is used for communication between the Motronic control module and special tool V.A.G. 1551.

Signal Failure

^ When there is a break in the signal wiring (K-wire), the following text appears on the V.A.G. 1551: "control module does not answer".