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Skoda Workshop Service and Repair Manuals

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Testing the speed signal > < Testing auxiliary signals

Fabia Mk1

Testing signals from the air conditioning system
Testing signals from the air conditioning system
The air conditioning system is connected to the engine control unit via the data BUS. All signals of the air conditioning system to the engine control unit or vice versa are transmitted via the data BUS.
Testing occurs via the measured value blocks of the air conditioning system and engine control unit.
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 condition
l  No data BUS fault → Electrical System; Rep. Gr.90
Test sequence
–  Connect vehicle system tester -V.A.G 1552-. Start engine and select “address word” 01 Engine electronics → Chapter.
–  Select function 08 “Read measured value block” and display group 002.
   
–  Readout on display:
Air conditioning switched off.
–  Observe display field 3.
   Specified value: X 1 0
–  Switch on the air conditioning system.
–  Observe display field 3.
   Specified value: X 1 1
  
Reading measured value block         2   ->
900/min       0.0%      010       90.0°C
Meaning, if display positions = 1 
XXXOperating position 
  1Air conditioning on 
 1 Idling switch closed (accelerator pedal not pressed)
1  Ignore

–  Switch off air conditioning again.
–  If the display does not occur as described:
–  Testing air conditioning system → Heating, Air conditioning; Rep. Gr.01
–  Testing data BUS → Electrical system; Rep. Gr.90
   

Testing the speed signal > < Testing auxiliary signals