Description of On-Board Diagnostics

DIAGNOSTIC TROUBLE CODE (DTC) MEMORY

Function
The Motronic Engine Control Module (ECM) (J220), which controls the fuel injection and ignition system, is equipped with Diagnostic Trouble Code (DTC) Memory. The Data Link Connector (DLC) is located behind a cover in the instrument panel, just below the heating and ventilation controls.

If malfunctions occur in the monitored sensors or components, they are stored in the DTC Memory.

You can check the DTC Memory and display the stored Diagnostic Trouble Codes after initiating the On Board Diagnostic (OBD) program using the VAG 1551 Scan Tool (ST).

The DTC Memory must be erased after the malfunction has been repaired.

A malfunction that affects Oxygen Sensor (O2S) control can only be read accurately after the car has been driven for at least 10 minutes.

Malfunctions which can be attributed to a temporary open circuit in the wiring or a loose terminal, will also be stored. These malfunctions will be displayed as sporadic "SP" and are automatically cancelled if they are not repeated after 50 engine starts.

NOTE:
- The Malfunction Indicator Lamp (MIL) (K83) in the instrument panel, must come on when the ignition is switched on, and go off when the engine has started.

- As long as malfunctions occur in the monitored sensors or components, and the monitoring conditions are met, the Malfunction Indicator Lamp will also come on with the engine running.

- 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.