Computers and Control Systems: Description and Operation

FUNCTION

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 started (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.

The Motronic Engine Control Module (ECM) J220 is equipped with Diagnostic Trouble Code (DTC) memory.

Malfunctions in monitored sensors or components are stored in DTC memory along with an indication of the type of malfunction. Check DTC memory and display stored Diagnostic Trouble Codes (DTC) by initiating the On Board Diagnostic (OBD) program using the VAG 1551 Scan Tool (ST). Refer to "On-Board Diagnostic/Checking Diagnostic Trouble Code Memory (Function 02)". Testing and Inspection

The DTC memory must be erased after the malfunction has been repaired. Refer to "On-Board Diagnostic/Erasing Diagnostic Trouble Code Memory (Function 05)". Testing and Inspection

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

Malfunctions that 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 malfunctions "SP" and are automatically cancelled if they are not repeated after 40 engine starts.

TECHNICAL DATA

Equipped with:
- DTC memory: Non-volatile memory and volatile memory 1)
- Rapid data transfer

1) Will be cancelled after 40th engine start if malfunction has not occurred again.

Engine Control Module (ECM) identification
See "On-Board Diagnostic/Connecting VAG 1551 Scan Tool and Selecting Function". Testing and Inspection

Engine Control Module (ECM) functions

NOTE: The Motronic ECM is equipped with various functions. Some functions can be carried out with ignition switched on or with engine running. The following table details the prerequisites for carrying out the individual functions.