Late 94

Diagnostic Trouble Code (DTC) Memory, displaying blink codes

Starting with 8.94 production (1995 m.y.), Golf III, Jetta III, and Cabrio vehicles are equipped with a special OBD 1 adapter for use with the On Board Diagnostic (OBD) system.

OBD 1 Adaptor:

The adapter is used to check Diagnostic Trouble code (DTC) Memory when the VAG 1551 Scan Tool (ST) is not available. Stored malfunctions are displayed as blink codes by the Malfunction Indicator Lamp (MIL) in the vehicle.






Blink code display is activated by using the adapter in conjunction with the vehicle's Data Link connector (DLC). The adapter makes the connection between connector sockets 15 (L-wire) and 4 (Battery Ground).

Malfunction recognition

Note: The MIL is illuminated when the ignition is switched on (check function). It stays on, going out once the engine has been started.

Each stored malfunction is represented by a four digit numerical blink code. When the display is activated, the Malfunction Indicator Lamp (MIL) will illuminate and blink the four-digit code. Blink codes are listed along with Diagnostic Trouble Codes (DTC) in the DTC table

Blink code sequence

The display sequence begins with the MIL blinking once. Approx. one second later the blink code sequence will begin.

The MIL will blink 1 to 9 times to display the first digit, then pause, blink again 1 to 9 times to display the second digit, and so on until all four digits have been displayed.

Displaying DTC blink codes

- Switch ignition ON.
- Connect OBD1 adapter to Data Link Connector (DLC) for 2.5 seconds, then disconnect.

First blink code will be displayed

Note: The code 4-4-4-4 indicates no malfunctions stored.

- Connect OBD1 adapter again for 2.5 seconds, then disconnect.

Next blink code will be displayed

- Repeat procedure, connecting and disconnecting adapter and reading additional blink codes, until no more codes are displayed (0-0-0-0).
- Switch ignition OFF.