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Engine control unit > < Test condition

Leon Mk2

Testing procedure
Testing procedure
Check the vehicle under cold start conditions during a road test.
  Note!
A second person is required for the road test.
  Caution
The fault finder must be secured in the back seat and operated from there.
–  Attach the unit -V.A.G. 1551- (-V.A.G. 1552-). Switch on the ignition and enter “direction code” 01 to select the engine control unit. (Fault finder: Connect and select the engine control unit → Vehicle diagnosis, testing and information system VAS 5051.)
   
Display reading:
–  Press the 0 and 8 buttons for the function “Read measurement values block” and confirm the entry with the Q button.
  
Rapid data transfer                 HELP
Select function XX
Display reading:
–  Press buttons 0, 9 and 9 for “Display group number 99” and confirm the entry with the Q button.
  
Read measurement values block       HELP
Enter display group number XXX
Display reading:
The Lambda probe's operating state is indicated in display field 4.
  
Read measurement values block 99       →
         1         2         3         4
Meaning of the figures in the 8 digit numerical block for the Lambda regulator's operating state.
xxxxxxxxMeaning in case of digits = 1
1       Fault detected by self-diagnosis
 0      Not occupied
  0     Not occupied
   1    Lambda control limited dynamism, active
    1   Lambda regulator at limit
     1  Lambda regulator activated
      1 Lambda probe ready
       1State of mixture:
Message = 1: Rich mixture
Message = 0: Lean mixture

–  Carry out the road test. During the road test, observe the operating state of Lambda regulation as it appears in display field 4.
   
Display reading:
  
Read measurement values block 99       →
       1       2       3        XXXXX00X
When Lambda regulation begins to operate, the Lambda probe must be in operating condition and the Lambda regulator must be activated.
If the faults in vehicle operating behaviour begin before Lambda regulation starts:
Lambda regulation cannot be the cause of the fault.
  Note!
If behaviour improves after Lambda regulation begins, it means that regulation intervenes by compensating for the fault's cause (for example: undue air, faulty injector, etc.). This can be detected by consulting the adaptive Lambda values.
If the fault in the vehicle's operating behaviour begins after Lambda regulation begins:
–  Test Lambda regulation → Chapter.
  
Read measurement values block 99       →
       1       2       3        XXXXX11X

Engine control unit > < Test condition