VAG 1551 Scan Tool (ST), Connecting, Checking Control Module Versions And Selecting Function

NOTE: The following description refers only to the VAG 1551 Scan Tool (ST).

1. Connect VAG 1551 scan tool. See Fig 1 .
2. Switch on ignition. Two operating modes are displayed alternately.
   • VAG - On Board Diagnostic (OBD) HELP
   • 1- Rapid data transfer
   • 2- Blink code output
   NOTE: If nothing appears on the display, check voltage supply for VAG 1551 scan tool according to wiring diagram.
   NOTE: Additional instructions can be called up via the HELP button on the scan tool.
   NOTE: Function 00 "Automatic test sequence" can be performed in operating mode 1 "Rapid data transfer." This automatically checks all control modules installed in the vehicle.
3. Switch printer on via the PRINT button (indicator lamp in button lights up).
4. Press button "1" to select "Rapid data transfer" operating mode 1. Indicated on display:
   • Rapid data transfer HELP
   • Enter address word XX
5. Press buttons "1" and "7" to input address word 17, "instrument cluster." Indicated on display:
   • Rapid data transfer Q
   • 17 instrument cluster
6. Press "Q" button to confirm input. Indicated on display:
   • Rapid data transfer Q
   • Scan tool sends address word 17
7. Appearing on the display is the instrument cluster identification number and the coding number. Indicated on display (values are examples only):
   • 7D0920901E T4-KOMBIINSTR. VDO X18: Top line of display is control module part number, system identification (instrument cluster), manufacturer code: VDO = VDO and version number.
   • Coding 03261 WSC 00000: Bottom line of display is coding number (depends on engine, transmission and optional equipment), and work shop code (automatically stored in the control module upon entry into the installed system. But not for coding of control modules that have already been used).
   NOTE: If "Control module not responding!" appears on the display, press "HELP" button to print out an overview of all of the possible malfunction causes. Enter address word 17 for instrument cluster again after correcting malfunction and press "Q" button to confirm.
8. Press forward (right) arrow button. Indicated on display:
   • Rapid data transfer HELP
   • Select function XX
9. Pressing the HELP button will print out an overview of all of the possible functions.
10. Indicated on the display is the "Select function" screen. These are all possible functions for the instrument cluster:
    • 01 - Check Control Module Versions 
    • 02 - Check DTC Memory 
    • 03 - Output Diagnostic Test Mode (DTM) 
    • 05 - Erase DTC Memory 
    • 06 - End Output 
    • 07 - Code Control Module 
    • 08 - Read Measuring Value Block 
    • 10 - Adaptation 
    NOTE: All possible instrument cluster OBD functions are indicated above. Do not attempt to select additional functions printed out via the HELP button. After function is completed, the VAG 1551 returns to the start position.
11. After function is completed, the VAG 1551 returns to the "Select function" start position.

Fig 1: Identifying VAG 1551 Scan Tool and VAG 1551/3 Diagnostic Cable

Courtesy of VOLKSWAGEN UNITED STATES, INC.