skoda Workshop Repair Guides

Skoda Workshop Service and Repair Manuals

ABOUT US
Testing the engine operating conditions > < Inspecting functions

Fabia Mk1

Testing idling speed
Testing idling speed
  Note
t  The idling speed cannot be adjusted.
t  The idling speed is checked during the basic setting of the engine.
t  During the basic setting the activated charcoal filter system soldenoid valve -N80- is closed and the air conditioning compressor is deactivated.
Special tools and workshop equipment required
t  Vehicle system tester -V.A.G 1552 -
t  Diagnostic cable -V.A.G 1551/3- or -V.A.G 1551/3A- or -V.A.G 1551/3B-
Test conditions
l  Exhaust system shut
l  Coolant temperature minimum 80 °C
l  Electrical consumers must be disconnected (the radiator cooling fan must be off during this test)
Test sequence
–  Connect vehicle system tester -V.A.G 1552-. Start engine and select the “address word 01” for engine electronics → Chapter.
–  Interrogate the fault memory → Chapter. There must not be any fault stored, rectify any faults present, erase fault memory, switch off engine and start again, conduct test drive and as a check once again interrogate fault memory.
–  Allow engine to run.
–  Select function 04 “Basic setting” and display group number 056.
   
Readout on display:
–  Check whether the actual idling speed in display field 1 (actual speed) corresponds with the value in display field 2 (nominal speed).
   Tolerance: ±10 rpm
  Note
t  The speed in display field 1 (actual speed) is indeed the actual engine speed.
t  The speed in display field 2 (nominal speed) is the theoretical speed calculated by the engine control unit.
t  In idle the engine control unit always attempts to adapt the (actual) speed to the specified speed (nominal).
t  This means that engine speed when idling (actual) should always be approximately the same as the engine speed (specified).
t  Display fields 3 and 4 serve as information and are not relevant for the inspection of the idling speed.
If the specified value is reached:
–  Press →.
  
System in basic setting 56
780/min     800/min      2.5 %     00000
Readout on display:
If the specified value is not reached:
–  Interrogate the fault memory again → Chapter.
If the idling speed is too high or too low and if there is no fault in the fault memory, perform the following inspections:
t  Test unmetered air in the intake system → Chapter
t  Inspecting throttle valve control unit → Chapter.
t  Testing solenoid valve for activated charcoal filter -N80 - → Chapter.
t  Perform adaptation of the throttle valve control unit → Chapter.
t  Testing the engine operating conditions → Chapter.
  
Vehicle system test                 HELP
Select function XX

Testing the engine operating conditions > < Inspecting functions