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Perform the following checks marked with a dot if the idling speed is too high or too low and there are no faults stored in the > < Checking exhaust emissions warning lamp K83

A3 Mk1

Checking idling speed
Checking idling speed
Special tools and workshop equipment required
t  Vehicle diagnosis and service information system -VAS 5052-
  Note
t  No leaks in exhaust system.
t  Coolant temperature at least 80 °C.
t  Electrical equipment switched off (radiator fan must not run during the test).
t  Air conditioner switched off.
t  No pressure gauge connected.
t  Vehicles with automatic gearbox: selector lever in position P or N
  Note
t  The idling speed cannot be adjusted.
t  The idling speed is tested during the basic setting of the engine.
t  During basic setting, the activated charcoal filter system solenoid valve (ACF valve -N80) is closed and the air conditioner compressor switched off.
Test sequence
–  Interrogate the fault memory → Chapter. There must not be any faults stored. If necessary, eliminate faults, erase fault memory, switch off and re-start engine, perform test drive and interrogate fault memory again as a check.
–  Leave engine idling.
  WARNING
The electric radiator fan should not be running.
–  Select the function “Start basic setting” and confirm.
–  Select “Display group number 056”.
–  Check whether the engine speed in display zone 1 (actual engine speed) is within the permissible tolerance range.
   
 Display zones
 1234
Display group 056: Idling speed stabilisation when idling at operating temperature
Displayxxx rpmxxx rpmx.x %X X X X X
DisplayActual engine speedSpecified engine speedIdling speed control
torque change		Operating statuses
Specification700...840 rpm → Note
640...760 rpm → Note		770 rpm → Note
700 rpm → Note		x.x %0 0 0 0 0
NoteIf the reading does not match the specification → Chapter  Explanatory notes on numbers
→ Chapter

1)  Manual gearbox, front and four-wheel drive
2)  Automatic gearbox, front-wheel drive
  Note
t  The engine speed in display zone 1 is the actual engine speed.
t  The engine speed in display zone 2 (specified engine speed) is a theoretical speed calculated by the engine control unit.
t  When the engine is idling the engine control unit tries constantly to adjust the actual engine speed so that it matches the specified value.
t  This means that the actual engine speed when idling should always be approximately the same as the specified engine speed.
t  Display zones 3 and 4 are provided for information purposes but have no relevance as regards checking of the idling speed.
If the reading matches the specification:
–  Press the → key.
If the reading does not match the specification:
–  Interrogate the fault memory again → Chapter.
–  If the fault memory has been erased, the readiness code must be generated again → Chapter.
   

Perform the following checks marked with a dot if the idling speed is too high or too low and there are no faults stored in the > < Checking exhaust emissions warning lamp K83