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Check the basic voltage > < Lambda regulation: test

Leon Mk2

Function test
Function test
–  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 buttons 0 and 8 for the function “Read the measurement values block” and confirm the entry with the Q button.
  
Rapid data transfer                 HELP
Select function XX
Display reading:
–  Press buttons 0, 0 and 1 for “display group 1” and confirm the entry with the Q button.
  
Read measurement values block       HELP
Enter display group number XXX
Display reading: (1...4 = display fields)
–  Check in display field 2 whether the coolant temperature is above 80 °C.
–  Change to display group as follows:
–  Press the C button.
  
Read measurement values block 1        →
         1         2         3         4
Display reading:
–  Press buttons 0, 2 and 0 for “Display group number 20” and confirm the entry with the Q button.
  
Read measurement values block       HELP
Enter display group number XXX
Display reading: (1...4 = display fields)
–  Check the operating state of Lambda regulation in display field 4:
Indication of Lambda regulation's operating state:
t  Fault in the fault memory:
The 1st digit from the left must be a 0
Value displayed: 00000000
t  Lambda regulation at limit:
The 4th digit from the right must be a 0
Value displayed: 00000000
t  Lambda regulation active:
The 3rd digit from the right must be a 1
Value displayed: 00000100
t  Lambda probe ready for operation:
The 2nd digit from the right must be a 1
Value displayed: 00000010
t  Mixture:
The 1st digit from the right must change back and forth between 0 and 1
Value displayed: 00000001 (1 = mixture rich)
Value displayed: 00000000 (0 = mixture lean)
  Note!
The remaining digits may be either 1 or 0.
–  Press the C button.
–  Press buttons 0, 0 and 1 for “display group 1” and confirm the entry with the Q button.
  
Read measurement values block 1        →
         1         2         3         4
Display reading: (1...4 = display fields)
–  Observe Lambda probe voltage in display field 3. The voltage must oscillate at least 30 times per minute, within the following range: 0.0...1.0 V
If the reading remains constant at one value:
  
Read measurement values block 1        →
         1         2         3         4
Value displayedCauseContinue testing
approx. 5.0 VShort to positive → Chapter test basic
voltage
1,50... 1,60 VBreak → Chapter check cables
approx. 0.0 VShort to earth 
 Short to cable 2 
oscillates
between 0.0...1.0 V		Regulation correct---

–  Press the button →.
–  Press buttons 0 and 6 for the function “End data transmission” and confirm the entry with the Q button.
If the theoretical values for the operating state of Lambda regulation are not reached, or if probe voltage does not oscillate as indicated:
–  Test Lambda probe heating → Chapter.
–  Check whether the Lambda probe has soot; renew if necessary.
   

Check the basic voltage > < Lambda regulation: test