Initial Inspection and Diagnostic Overview

Diagnostic Trouble Code (DTC) Memory, general information

The Mono-Motronic Engine Control Module (J257) 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 at monitored sensors or components, they are stored in the DTC Memory. You can check DTC Memory and display the stored Diagnostic Trouble Codes (DTC) after initiating the On Board Diagnostic program using the VAG 1551 Scan Tool (ST).

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

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 Diagnostic Trouble Codes (DTC).
^ To reset the VAG 1551 Scan Tool to start from the beginning of the On Board Diagnostic (OBD) program, press the -C- button or briefly disconnect and reconnect the adapter cable.

A malfunction that affects oxygen sensor control can only be read accurately after the car has been driven for at least 10 minutes.


Technical data

Equipment and functions of the Mono-Motronic Engine Control Module (J217):
^ DTC Memory: permanent memory
^ DTC sporadic memory (erased after 10th start if malfunction has not reoccurred)
^ Rapid data transfer
^ Output Diagnostic Test Mode (DTM)
^ Read measuring value block
^ Engine basic setting