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Measured value blocks > < Final control diagnosis

Polo Mk3

Performing final control diagnosis
Performing final control diagnosis
Special tools and workshop equipment required
t  Fault reader -V.A.G 1551- or vehicle system tester -V.A.G 1552- with diagnosis cable -V.A.G 1551/3-
The final control diagnosis activates the following components in the stated sequence:
1. Commencement of injection valve -N108-
2. Exhaust gas recirculation valve -N18-
3. AC compressor shut-off function
4. Throttle valve positioner -V60-
5. Fuel shut-off valve -N109-
6. Glow plug relay -J52-
7. Glow period warning lamp -K29-
Vehicles with m-equipment only.
8. Low heat output relay -J359-
9. High heat output relay -J360-
  Note
t  Activation of individual control elements is limited to 30 secs. but can be stopped at any time by pressing the → button.
t  The ignition must be switched off before repeating the final control diagnosis.
Procedure
–  Connect fault reader -V.A.G 1551- or vehicle system tester -V.A.G 1552-. Start engine and select “Address word” 01 of engine control unit. ((Connect fault reader -V.A.G 1551- and select engine control unit → Chapter)
   
Indicated on display:
–  Operate fault reader -V.A.G 1551- taking into account the information on the display:
–  Press buttons 0 and 3 for function “Final control diagnosis”.
  
Rapid data transfer                 HELP
Select function XX
Indicated on display:
–  Confirm entry with Q button.
  
Rapid data transfer                    Q
03-Final control diagnosis
Indicated on display:
Actuating the valve results in a significantly audible change in combustion noise (knocking).
If no change in combustion noise is heard:
–  Checking injection timing control range → Chapter
–  Press → button.
  
Final control diagnosis               ->
Commencement of injection valve N108
Indicated on display:
The valve must click.
  Note
t  The valve clicking cannot be heard because of engine noises and can therefore only be felt by touch.
t  The piston movement of the mechanical exhaust gas recirculation valve -N18- is clearly visible at the side slot.
If the valve does not click:
–  Check exhaust gas recirculation valve -N18- → Chapter.
–  Press → button.
  
Final control diagnosis               ->
Exhaust gas recirculation valve N18
Indicated on display:
Air conditioner compressor switch-off is checked.
The test step is also recalled on vehicles without air conditioner system.
–  Continue final control diagnosis.
–  Press → button.
  
Final control diagnosis               ->
Conditioner compressor interruption
Indicated on display:
The solenoid valve must click.
  Note
The clicking of the valve is difficult to hear and is therefore best checked by touch.
If the valve does not click:
–  Check throttle butterfly valve -N211- → Chapter.
–  Press → button.
  
Final control diagnosis               ->
Throttle valve positioner V60
Indicated on display:
The engine must stop.
If the engine does not stop:
–  Switch off ignition.
–  Unscrew fuel shut-off valve -N109- and remove any metal particles or dirt.
–  Repeat final control diagnosis. If the engine does not stop, renew fuel shut-off valve -N109- → Item.
–  Continue final control diagnosis with engine stopped and ignition switched on.
–  Press → button.
  
Final control diagnosis               ->
Fuel shut-off valve N109
Indicated on display:
The relay must click.
Switching on and off the relay can also be observed as the interior light becomes brighter and darker as a result of the glow plug high power consumption.
If the relay does not click:
–  Check glow plug relay -J52-: → Current flow diagrams, Electrical fault finding and Fitting locations
–  Press → button.
  
Final control diagnosis               ->
Glow plug relay J52
Indicated on display:
The warning lamp must flash.
If the warning lamp does not flash:
–  Check glow period warning lamp -K29-: → Current flow diagrams, Electrical fault finding and Fitting locations
–  Press → button.
Vehicles with m-equipment only.
  
Final control diagnosis               ->
Glow period warning lamp K29
Indicated on display:
The relay must click.
If the relay does not click:
–  Check low heat output relay -J359-: → Current flow diagrams, Electrical fault finding and Fitting locations
–  Press → button.
  
Final control diagnosis               ->
Low heat output relay J359
Indicated on display:
The relay must click.
If the relay does not click:
–  Check high heat output relay -J360-: → Current flow diagrams, Electrical fault finding and Fitting locations
–  Press → button.
  
Final control diagnosis               ->
High heat output relay J360
Indicated on display:
–  Press buttons 0 and 6 for function “End data transfer” and confirm entry with Q button.
–  Switch off ignition.
  
Rapid data transfer                 HELP
Select function XX

Measured value blocks > < Final control diagnosis