Diagnostic Signal

OPERATION
The Diagnostic Signal is connected to pin C 12 of the Engine Control Module, the signal is directional OUT only (PIN C 12 - OUTPUT ONLY).

PURPOSE
The diagnostic signal is used for communication between the Engine 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".