With Manufacturer's Scan Tool

On Board Diagnostic (OBD)

General Information

The engine control module (Motronic control module -J220- is equipped with a Diagnostic Trouble Code (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 malfunctions.

After evaluating the information, the Engine Control Module (ECM) distinguishes between the DTCs listed in the DTC table and stores these until DTC memory is erased. Testing and Inspection

Malfunctions which only occur sporadically will have the addendum "sporadic fault" 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°C coolant temperature - switched off above 72°C), it will be erased from the DTC memory.

The DTCs stored can be read-out with the new tester VAS 5051, the V.A.G 1551 Scan tool or the or 1552 scan tool. Reading Diagnostic Trouble Codes

The DTC memory must be erased after the malfunctions have been eliminated. Clearing Diagnostic Trouble Codes

If DTC memory is erased, the Engine Control Module (ECM) will unlearn some adaptation values. Depending on vehicle mileage, this can cause driveability problems. In this case, let engine run at idle for several minutes or perform a road test until the adaptation procedure has been completed.

Switch the ignition on for approx. 10 seconds if the Engine Control Module (ECM) was disconnected from B+. Switch the ignition off for approx. 50 seconds (control module after-run) in order to permanently store the throttle valve adaptation, if performed.

NOTE: General information for On Board Diagnostic can be found in the instruction manuals for the V.A. G 1551 scan tool, or 1552 scan tool or the new tester VAS 5051.