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Additional signals checking > < Component test

Leon Mk1

Engine operating conditions checking
Engine operating conditions checking
  Note!
Checks whether engine control unit recognises the engine operating modes (idling, overrun, part throttle, enrichment, full throttle).
Special tools and workshop equipment required
t  Fault reader -V.A.G 1551- or vehicle system tester -V.A.G 1552- with cable -V.A.G 1551/3B-
Test conditions
l  Coolant temperature, 80 °C, minimum → display group 04, display field 3.
Prüfablauf
–  Connect fault reader -V.A.G 1551/V.A.G 1552- (V.A.G 1552). Start engine and select “Address word” 01 of engine control unit. (Fault reader: Connecting and selecting the engine control unit → Chapter).
   
Indicated on display:
–  Press keys 0 and 8 for the function “Read measured value block” and confirm entry with Q -key.
  
Rapid data transfer                 HELP
Select function XX
Indicated on display:
–  Press keys 0, 0 and 5 for “Display group number 5” and confirm entry with Q -key.
  
Read measured value block           HELP
Input display group number XXX
Indicated on display: (1...4 = Display fields)
–  Check whether the control unit recognises the operating conditions (display field 4):
t  Idling:
As long as the engine is running at idling speed idling must be displayed
Display: Idling
t  Overrun mode:
–  Increase engine speed to above 3000 RPM.
–  Close throttle valve quickly:
As long as the engine speed is above 1400 RPM overrun must be displayed:
   Display: Overrun
  Note!
Below 1400 RPM idling speed will be recognised.
t  Part throttle:
–  Rev up evenly.
As long as the engine is being revved up evenly, part throttle must be displayed:
   Display: Part throt
t  Enrichment:
–  Depress accelerator pedal completely (throttle burst).
The display must briefly read enrichment in acceleration.
   Display: Enrichment
t  Full throttle:
–  Accelerate to full throttle (throttle valve fully open).
Display should briefly read full throttle.
   Display: Full throttle
  Note!
A test drive may have to be performed to show “Full throttle” in display.
Observe the valid safety precautions when carrying out a road test → Chapter.
–  Press → -key.
–  Press keys 0 and 6 for the “End output” function and confirm input with the Q -key.
If the specifications are not attained:
–  Interrogate fault memory, eliminate any faults and clear the memory → Chapter; Fault memory: consulting and clearing.
–  Check throttle valve control part → Chapter.
  
Read measured value block           5 ->
         1         2         3         4

Additional signals checking > < Component test