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Engine speed signal: check > < Test condition

Leon Mk2

Testing procedure
Testing procedure
–  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, 0, and 2 for “Display group number 2” and confirm the entry by pressing the Q button.
  
Read measurement values block       HELP
Enter display group number XXX
Display reading: (1...4 = display fields)
Carry out a road test, during which a second person must observe the values that appear on the display.
–  Observe the value displayed in field 3: Theoretical value: approximate vehicle speed
–  Press the button →.
–  Press buttons 0 and 6 for the function “End data transmission” and confirm the entry with the Q button.
–  Switch off the ignition.
If no speed appears in the display:
  
Read measurement values block 2        →
         1         2         3         4
–  Attach the test box -V.A.G. 1598/22- to the control unit cabling harness.
–  Attach the diode lamp between female sockets 3 (positive) and 20 (speed signal).
–  Lift the front left part of the vehicle.
–  Switch on the ignition and turn the front left wheel by hand.
–  The diode lamp must blink (very brief intermittent signal).
  Note!
During the procedure, the right front wheel must not turn; if necessary, restrain its motion.
–  If the diode lamp does not blink, check for a break or short in the cable that goes from engine control unit contact 20 to the instrument panel. → Current flow diagrams, Electrical fault finding and Fitting locations
  N24-0709

Engine speed signal: check > < Test condition