General Information

On Board Diagnostic (OBD), features

The -J220- Engine Control Module (ECM) is equipped with a DTC memory.

If malfunctions occur in the sensors and components being monitored, they will be stored in DTC memory together with an indication of the malfunction type.

After evaluating incoming data, the ECM can pick between different possible DTCs, DTC table, and store them until the contents of DTC memory is intentionally erased, Diagnostic Trouble Code (DTC) memory, checking and erasing. Reading Diagnostic Trouble Codes

Malfunctions which only occur sporadically will have the words "sporadic malfunction" shown on the print out. These malfunctions will be indicated on the display by the suffix "/SP." These malfunctions can be caused by a loose terminal or a briefly open circuit. If a sporadic malfunction does not occur again within 40 warm-up phases (if engine started below 50 °C Engine Coolant Temperature and switched OFF above 72 °C), it will automatically be erased from DTC memory.

The DTCs stored can be read-out with the scan tools VAG 1551 or 1552 or the new tester VAS 5051.

The DTC memory must be erased after the malfunctions have been eliminated and the readiness code must be generated again.
Reading Diagnostic Trouble Codes
Monitors, Trips, Drive Cycles and Readiness Codes

All values learned by the engine control module will be erased when the engine control module connector is pulled off or the battery is disconnected. However the contents of the DTC memory are retained. When the engine is subsequently started the idling could be rough for a brief period. In this case leave the engine running for a few minutes at idle speed or perform a longer test drive, until the learning process is completed. Procedure after correcting voltage supply open circuit. Procedure After Correcting Voltage Supply Open Circuit


NOTE: General information for On Board Diagnostic (OBD) can be found in the instruction manuals for the scan tools VAG 1551 or 1552 or the tester VAS 5051.