Connecting Scan Tool (VAG 1551)

Ensure circuit breakers (S72 and S75), fuse No. 19 (25-amp) and fuel pump relay check in good condition. See Figure.

1. To connect SCAN TOOL (VAG 1551), first gain access to Data Link Connector (DLC). Open hood and remove plenum cover from under windshield. Remove cover to access DLC in relay fuse block (relay station No. 1). See Fig 1 and Fig 2 . Ensure ignition switch is in OFF position. Connect (Black) connector from adaptor cable (VAG 1551/1) to Black DLC in Relay Station (note: the shape and color of the DLC when making this connection).
2. Indicated on display is 2 messages, on display line 1 - "VAG ON BOARD DIAGNOSTIC". On the lower display line 2 messages will alternately between: "RAPID DATA TRANSFER" and "BLINK CODE OUTPUT".
3. If there is NO display on scan tool, verify connection for scan tool is Okay. If scan tool connections are Okay, check for battery voltage at Black DLC. See COMPUTERIZED ENGINE CONTROLS . Repair as necessary. Connect white adaptor cable connector to (White/Brown) DLC.
4. If display appears on scan tool, operate scan tool according to scan tool display information. See RETRIEVING DIAGNOSTIC TROUBLE CODES and DIAGNOSTIC TROUBLE CODE IDENTIFICATION under SELF-DIAGNOSTIC SYSTEM in SELF-DIAGNOSTICS article. For DIAGNOSTIC TEST MODES. See OUTPUT DIAGNOSTIC TEST MODE (DTM) in SELF-DIAGNOSTICS article.

Fig 1: Identifying Diagnostic Scan Tool (VAG 1551)

Courtesy of AUDI OF AMERICA, INC.