V8 Quattro V8-3562cc 3.6L DOHC (PT) (1990)
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Extracting Diagnostic Trouble Codes Using LED Test Light
Blink codes may be retrieved with a "LED" test lamp.
EXCITER SIGNAL
Description
The Exciter Signal is connected to pin 13 of the Motronic control module, the signal is directional IN only (PIN 13 - INPUT ONLY).
The exciter 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".
BLINK CODE OUTPUT SIGNAL
Description
The Blink Code Output Signal is connected to pin 22 of the Motronic control module, the signal is directional OUT only (PIN 22 - OUTPUT
ONLY).
This signal is used for blink codes (Diagnostic Trouble Codes). The malfunction indicator lamp (CHECK ENGINE) in the dash panel of vehicles
with California emissions is activated by this signal. The blink code output signal is also supplied to one of the data link connectors for LED test
light blink code access.
DIAGNOSTIC SIGNAL
Description
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 unit does not answer".
