Description of On-Board Diagnostics

The Motronic engine control module (J 220) controls the fuel injection and ignition system. It is equipped with a Diagnostic Trouble Code (DTC) Memory.

- If malfunctions occur in monitored sensors or components a DTC indicating the type of malfunction is stored in the DTC MEMORY.

- Stored DTC's can be displayed and erased with the VAG 1551 scan tool.

- To display DTC's relating to the 02S (Oxygen Sensor) control function you must drive the vehicle for a minimum of 10 minutes.

- DTC's will also be stored which can be attributed to a temporary open circuit or loose terminal. These are displayed as SP or sporadic faults.

- he DTC MEMORY must be erased after the malfunctions have been eliminated.

Malfunction Indicator lamp (MIL).

- The MIL lamp in the instrument panel must light up when the ignition is switched ON and then must switch OFF when the engine starts

- As long as interferences occur in the monitored sensors or component and the monitoring conditions are fulfilled, the MIL lamp will continue to remain lit, even with the engine running.

Note:If the VAG 1551 Scan Tool is not available, DTC MEMORY can also be activated and erased using an adaptor or locally made jumper.The MIL can be used to read the DTC's during this process.