Reading Diagnostic Trouble Codes

***UPDATED BY TSB #908902 dated 07-31-89.

Reading and Displaying Trouble Codes (California)

NOTE: This procedure applies to vehicles produced prior to January 1989. From January 1989, the On-Board diagnostic system has been disabled at the factory. Furthermore, some vehicles produced prior to January 1989, may have been modified at VW dealerships to incorporate this change. Check vehicle history and production date to determine if this procedure applies.

Check Engine Light Switch:

1. Turn ignition "ON", but do not start the engine.
2. Depress the "CHECK" rocker switch, located on the instrument panel, for at least four seconds.

Fault Code Display:

^ The fault indicator "CHECK" light will illuminate for approx. 2.5 seconds; then begin to flash codes. Example of flash code display: 2 flashes, a pause, 3 flashes, a pause, 4 flashes, a pause, followed by 2 flashes. The CODE 2-3-4-2 has been displayed.

3. Record the fault code.
4. After the fault code has been displayed, depress the rocker switch again for at least four seconds. The next recognized fault code, if present, will be displayed.

5. Continue the above procedure until CODE 0-0-0-0 (end of fault sequence) is displayed. CODE 0-0-0-0 is displayed as a series of four 2.5 second flashes with 2.5 second pauses (light off) in between.
6. After all of the fault codes are recorded, refer to the FAULT CODE TABLES for fault location and possible causes.
Refer to TESTING BY FAULT CODES for detailed test procedures. After the indicated fault(s) have been corrected, erase the fault code memory.

ERASING FAULT CODES

7. Turn the ignition switch "OFF".
8. Depress the "CHECK" rocker switch. With the switch depressed, turn the ignition "ON".
9. Continue to depress the "CHECK" rocker switch for approx. 5 seconds, then turn the ignition "OFF".

NOTE: If all previous fault codes have been successfully removed, reactivating the fault code memory should produce a code #4-4-4-4 (no faults present).

10. Road test vehicle for a minimum of ten minutes.

11. If the "CHECK" light comes on during road test repeat steps 1-10.