General Information

On Board Diagnostic II, general information and features

The Engine Control Module (ECM) (Motronic J220) is equipped with a Diagnostic Trouble Code (DTC) memory.

If a malfunction occurs in any of the monitored sensors and components, a DTC will be stored in DTC memory together with an indication of the type of malfunction.

After evaluating the information, the ECM decides between 106 different malfunctions and stores the appropriate code in DTC memory until the contents are erased.

Malfunctions which only occur sporadically will have the note "sporadic malfunction" on the print out. These malfunctions will be indicated on the display by the addendum "/SP". The cause of sporadic malfunctions can be e.g. a loose terminal or a brief open circuit. If a sporadic malfunction does not occur again within 40 warm-up phases (engine start below 50 °C Engine Coolant Temperature - switched off above 72 °C), it will be erased from DTC memory.

Stored DTC's can be displayed using the VAG 1551/1552 Scan Tool.
- Display the Readiness Code.

If the DTC memory has been erased or the ECM disconnected from the battery, the Readiness Code must be created again.