Page 1 of 97

01-1
 
     
On Board Diagnostic (OBD) 
     
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 VAG1551 
Scan Tool (ST)   page 01
-16
 .  
      After the necessary repairs are completed, DTC 
memory must be erased   page 01
-49
 .  
      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 
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        Page 10 of 97

01-7
 Modes under address word 33:  Mode 1: Transfer diagnostic data   Ignition switched on -or- Engine running at idle  
Mode 2: Transfer operating conditions   Ignition switched on -or- Engine running at idle  
Mode 3: Check DTC memory   Ignition switched on -or- Engine running at idle  
Mode 4: Erase diagnosis information   Ignition switched on -or- Engine running at idle  
Mode 5: Output of HO2S signals   Ignition switched on -or- Engine running at idle  
Mode 6: Transfer measuring values   Ignition switched on -or- Engine running at idle  
Mode 7: Check DTC memory   Ignition switched on -or- Engine running at idle   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.
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        Page 14 of 97
01-9
      
Connecting  
    
Notes: 
 Scan tool operating instructions    -  Locate Data Link Connector (DLC), under driver's knee bar to left of 
steering wheel. 
-  Connect VAG1551 Scan Tool (ST) with VAG1551/3 adapter cable to 
DLC. 
-  Switch ignition on, or start engine, depending on function to be 
selected (   page 01
-5 ). 
If scan tool displays do not appear as indicated:If "Error in communication link" is displayed, disconnect adapter cable 
at scan tool, reconnect, and repeat procedure. 
-  Operate scan tool and advance through program sequence by 
following display: 
  -  Press button -1- to select "Rapid data transfer" operating mode 01.
  -  Press buttons -0- and -1- to insert "Engine Electronics" address word 
01, and press -Q- button to confirm input. 
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        Page 15 of 97
01-10
 
4D0907551A 2.8L V6/5V MOTR HS D01 Coding 06051 
WSC 00000
    
Indicated on display (ECM identification and coding, example)  
4D0 _ _ 
_   Engine Control Module (ECM) Part No.  
2.8 L   Engine displacement  
V6/5V   Engine type:   
V-engine, 6-cylinder, 5-valve  
MOTR   Motronic  
HS  
AT  Manual transmission  
Automatic transmission  
D..   ECM software version  
Coding   ECM coding  
Coding variations   page 01
-14
   
WSC 
12345  Plant number: indicates where VAG1551 scan tool was used 
for last coding and/or adaptation (as long as factory coding 
has not been changed, WSC 00000 is displayed)  
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        Page 16 of 97
01-11
      
Notes:  
     If the ECM version that corresponds to the 
vehicle is not displayed, replace ECM   page 
01
-68
 . Incorrect ECM coding leads to: 
     
Performance problems (e.g. jerky shifting, 
abrupt load changes, etc.) 
     Increased fuel consumption
     Elevated exhaust gas values
     Reduction in transmission service life
     Storage of non-existent malfunctions in DTC 
memory 
     Necessary functions not being carried out 
(oxygen sensor control, actuation of EVAP 
canister system, etc.) 
     
- 
Press   button to advance through program 
sequence. 
Rapid data transfer 
HELP
Select function XX
    
Indicated on display  
-  Continue as specified in procedures for specific OBD functions.
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        Page 17 of 97

01-12
      
Code Control Module (scan tool function 
07)
 
      If vehicle coding information is not as specified, 
or if the ECM has been replaced, the ECM must 
be coded as follows.  
     
Required special tools and test equipment  
     VAG1551 Scan Tool (ST) with VAG1551/3 
adapter cable 
     
Coding procedure  
     
-  Connect VAG1551/VAG1552 Scan Tool (ST) 
and press buttons -0- and -1- to insert "Engine 
Electronics" address word 01 (ignition switched 
on)  page 01
-8 . 
Rapid data transfer 
HELP
Select function XX
    
Indicated on display  
-  Press buttons -0- and -7- to select "Code Control Module" function 07, 
and press -Q- button to confirm input. 
Code Control Module 
HELP
Input code number XXXXX 
(0-32000
)
    
Indicated on display  
-  Input applicable code number for vehicle, and press -Q- button to 
confirm input. ECM coding variations   page 01
-14
 . 
Function is unknown or 
    
If indicated on display:  
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        Page 19 of 97
01-13
 
4D0907551A 2.8L V6/5V MOTR HS D01 Coding 06051 
WSC 00000
    
Indicated on display (ECM identification and coding, e.g. 06051)  
- 
Press   button to advance through program sequence.
Rapid data transfer 
HELP
Select function XX
    
Indicated on display  
Notes:  
The Motronic ECM -J220- only uses the code that has been entered after 
the ignition has been switched off once. Incorrect coding leads to:  -  Press buttons -0- and -6- to select "End Output" function 06, and press 
-Q- button to confirm input. 
Performance problems (e.g. jerky shifting, abrupt load changes, etc.)Increased fuel consumptionElevated exhaust gas valuesStorage of non-existent malfunctions in DTC memoryReduction in transmission service life
Pa
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        Page 22 of 97
01-16
      
Check DTC Memory (scan tool function 
02)
 
     
Required special tools and test equipment  
     VAG1551 Scan Tool (ST) with VAG1551/3 
adapter cable 
     
Checking  
     
-  Connect VAG1551/VAG1552 Scan Tool (ST) 
and press buttons -0- and -1- to insert "Engine 
Electronics" address word 01 (engine running at 
idle)  page 01
-8 . 
     
Note:  
     If engine does not start: 
     - Operate starter to crank engine for approx. 6 
seconds, then do not switch ignition off. 
     
-  Press PRINT button to switch scan tool printer 
on (indicator light in button lights up). Rapid data transfer 
HELP
Select function XX
    
Indicated on display  
-  Press buttons -0- and -2- to select "Check DTC Memory" function 02, 
and press -Q- button to confirm input. 
Pa
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