With Manufacturer's Scan Tool

On Board Diagnostic (OBD), Features

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

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

After evaluating the information, the engine control module decides among different codes, DTC table or, DTC table and stores these until the contents of the DTC memory is erased.

Malfunctions which only occur sporadically will have the addendum "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 contact or a brief open circuit. If a sporadic malfunction does not occur again within 40 warm-up phases (engine start below 50 degrees C coolant temperature - switched off above 72 degrees C), it will be erased from the DTC memory.

The codes stored can be read with the V.A.G1551 scan tool, the V.A.G1552 mobile scan tool or the new tester VAS5051.

The DTC memory must be erased after the malfunctions have been eliminated and the readiness code must be generated again.

If the voltage supply is interrupted, the engine control module loses all the "learned" and/or "basic" values for oxygen sensor control, idling speed and charge pressure. Therefore considerable driving characteristic problems may occur depending on vehicle mileage.

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 idling speed or perform a longer test drive, until the learning process is completed.

NOTE: General information for On Board Diagnostic (OBD) can be found in the instruction manuals for the V.A.G1551 scan tool, V.A.G1552 mobile scan tool or the new tester VAS5051.