General Information

Function

The Multiport Fuel Injection (MFI) system is equipped with an Engine Control Module (ECM) -J220- with On Board Diagnostic (OBD) capability.

When malfunctions occur in sensors or components monitored by OBD, Diagnostic Trouble Codes (DTC) are stored in DTC memory.

Stored DTCs are identified using the VAG 1551 Scan Tool (ST).

After the necessary repairs are completed, DTC memory must be erased.

OBD II legal regulations require a display (readiness code) that shows inspection readiness for the annual exhaust emissions test. The readiness code shows that every component and/or system that affects exhaust emissions, which can lead to the Malfunction Indicator Lamp (MIL) being switched on, has been operated at least once with positive results.

The readiness code is reset and/or erased and must be regenerated every time DTC memory is erased, the power supply to the ECM -J220- is interrupted (example: when connecting test box VAG 1598/19), or the battery has been disconnected. Readiness Code, Generating

Malfunction Indicator Lamp (MIL) Function, Checking

If a malfunction is recognized by the Engine Control Module (ECM) or the Transmission Control Module (TCM), this is indicated by the MIL coming on.

Malfunction Indicator Lamp (MIL)







NOTE: When a recognized malfunction switches on the MIL, it will either blink or light continuously. In either case, DTC memory must be checked.


- If the MIL starts to blink, there is a malfunction that can lead to damage of the Three Way Catalytic Converter (TWC). In this case, driving should only continue using reduced power. The malfunction must be rectified as quickly as possible.
- If the MIL lights continuously, there is a malfunction that affects exhaust emissions. In this case, DTC memory must be checked, and the malfunction must be rectified as quickly as possible.
- Some malfunctions may occur without causing the MIL to come on. When driveability or performance problems are reported, and there is no indication from the MIL, the operation of the MIL must be checked. In addition, DTC memory must be checked, as there may be malfunctions stored that do not switch the MIL on immediately.


Checking function

- Switch ignition on.
- MIL must light up.
- If MIL does not light when ignition is switched on, check wiring to MIL as follows:







If MIL lights up when ignition is switched on, continue checking as follows:
- Start engine and let run at idle.
- MIL must go out after a few seconds.

If MIL does not go out:
- Check Diagnostic Trouble Code (DTC) memory.

If there are no malfunctions stored in DTC memory:







On Board Diagnostic (OBD) Technical Data

Memory
- Temporary memory and permanent memory. If the engine control module is disconnected from the Battery Positive Voltage (B+) supply, the readiness code and learning values will be erased. Any malfunctions stored in DTC memory are not erased.

Data output
- Rapid data transfer
- Additional malfunction indication by Malfunction Indicator Lamp (MIL) lighting up

ECM Identification
VAG 1551/VAG 1552 Scan Tool (ST), connecting and selecting "Engine Electronics" address word 01

ECM functions
- The Motronic ECM -J220- performs different OBD functions, carried out with the ignition switched on or with the engine running. Following are the conditions required to carry out each of the specific functions.

Address words:







Functions under "Engine Electronics" address word 01:












Modes under address word 33:







- Under Address word 33, Modes 1-7 can be addressed.
- Under Mode 1, individual measuring values can be displayed. Mode 1 is not recommended for use in an Audi Service department, because these values can be displayed much more precisely using address word 01 and "Basic Setting" function 04 or "Read Measuring Value Block" function 08.
- Mode 2 shows the operating conditions under which the stored malfunctions were recognized.
- With Mode 3, DTC memory is checked-with Mode 4, DTC memory is erased.
- Mode 5 shows the statistical value of the oxygen sensors as mandated by law. As these values have no direct bearing on oxygen sensor diagnosis, Mode 5 is of no particular value in an Audi Service department.
- Under Mode 6, values can be checked for components and systems that are not continuously monitored.
- With Mode 7 all malfunctions can be checked, even if they have not switched on the Malfunction Indicator Lamp (MIL) (if the MIL has not been switched on, there is no malfunction recognized under Mode 3)