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.

NOTE:
- The Malfunction Indicator Lamp (MIL) in the instrument panel, must light up when the ignition is switched on, and go off when the engine is running.

- As long as malfunctions occur in the monitored sensors or components and the monitoring conditions are met, the Malfunction Indicator Lamp lights up even with the engine running.

Malfunctions are stored and displayed as follows:

^ Malfunctions that occur briefly are stored as "sporadic" and are displayed with the code "SP".

^ Only malfunctions that are present when the DTC Memory is checked are stored and displayed as DTCs.

^ To reset the VAG 1551 Scan Tool to start from the beginning of the On-Board Diagnostics program, press the -C- button, or briefly disconnect and reconnect the adapter cable.