Exciter Wire Signal
The Exciter Wire Signal is connected to pin 13 of the Motronic control module, the signal is directional IN only (PIN 13 - INPUT ONLY).The exciter wire signal is used for activation of rapid data download (Diagnostic Trouble code extraction) via the white data link connector (L-wire).
Signal Failure
^ When there is a break in the signal wiring (L-wire), the following text appears on the V.A.G. 1551: "control unit does not answer".