Diagnostika OBD1 VW

Volkswagen Trouble Codes

Some years and models may not be applicable.


  1. Turn the ignition ON. Connect the black end of the jumper cable to the black diagnostic connector in center console under shift boot. Connect the white end of the jumper to the white diagnostic connector.
  2. After five seconds the OBD CHECK light should begin to flash. Remove the jumper, but do not turn off the ignition. Record the flashes.
  3. When code 4444 or 0000 appears, then either turn off the ignition or reinstall the jumper to end code readout.

Possible wiring faults should be checked and corrected before replacing a suspected component. Once the fault is corrected, the permanent fault memory should be erased as described below.

    1. Make sure the ignition is OFF. Connect the jumper cable as described in RETRIEVING CODES. Turn the ignition ON.
    2. After 5 seconds remove the jumper cable. The OBD light should flash 4444. Turn the ignition Off or reinstall the jumper cable to end the procedure.


The Digifant I ECU must be reset to its reference setting after certain conditions or repairs as follows:

  • The blue coolant temperature sensor connector has been disconnected with the engine running
  • The following components have been replaced:
    • Digifant ECU
    • Air Flow Sensor
    • Throttle Valve Potentiometer
    • Throttle Valve Body

When resetting the ECU, the engine must be at normal operating temperature, all electrical accessories must be Off, the idle stabilization system must be okay, and the exhaust system must be leak-free.

  1. With the engine off, disconnect the crankcase ventilation hose from the emission control valve atop the valve cover, then plug the hose. Start the engine and let it idle. Disconnect the blue coolant temperature sensor harness connector.
  2. Let the engine idle for one minute, then reconnect the harness connector. CAUTION: DO NOT reconnect the coolant temperature sensor harness connects, while the radiator cooling fan is running.
  3. Turn the engine off and reconnect the crankcase ventilation hose. Erase the OBD fault memory.

NOTE: Disconnecting the coolant temperature sensor with the engine running generates fault code 2312.

Retrieving Codes (Bosch Motronic CIS-E)

The Bosch Motronic system (CIS-E) requires a scanner to retrieve and clear the trouble codes.

Trouble Codes

CIS-E Motronic - Digifant Systems
VR-6 Motronic System
96-97 All - 98 Jetta - Diesel Turbo Direct Injection
96-00 Motronic OB II System
98-00 New Beetle - Passat - Diesel Turbo Direct Injection
99-00 Jetta - Diesel Turbo Direct Injection