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Fuel preparation system Diesel injection > < Actuator diagnosis

Leon Mk1

Actuator diagnosis: performance
Actuator diagnosis: performance
Special tools and workshop equipment required
t  fault reader -V.A.G 1551- with cable -V.A.G 1551/3B-
Checking conditions
l  Fuse number 20, correct.
l  Fusible links in fuse holder/battery, correct.
l  Battery voltage, 11.5 V minimum.
l  Ground connections in the water box, correct.
l  All electrical consumers, for example: the lights and heated windscreen, must be turned off.
Testing conditions for vehicles with air conditioning
l  The vehicle must be at room temperature (over + 15 °C).
l  Air conditioning open.
l  Minimum temperature and maximum turbine revolutions preselected.
During the actuator diagnosis, the following components are activated in the indicated order:
1. Valve for starting injection -N108-
2. Valve for exhaust gas recirculation -N18-
3. Intervention of the air conditioning compressor
4. Motor for inlet manifold plate -V157-
5. Fuel cut valve -N109-
6. Relay for glow plugs -J52-
   Warning light for preheating time -K29-
7. Relay low calorific power -J359- (only vehicles with optional units)
8. Relay high calorific power -J360- (only vehicles with optional units)
  Note!
t  During the actuator diagnosis, the different actuators are activated for some 30 seconds, unless the key → is pressed first to pass on to the following
t  Before repeating the actuator diagnosis, the ignition must be turned off
Sequence of operations
–  Connect the -V.A.G 1551- unit (-V.A.G 1552-) and, using the corresponding “direction code” 01, select the control unit for engine electronics. When doing this, the engine must be idling. (Fault reader: Turn on and select the control unit for engine electronics → Chapter).
   
Indication on the display:
–  Run the fault reader bearing in mind the indication on the display
–  Press the keys 0 and 3 for the function “Actuator diagnosis”.
  
Fast data transmission              HELP
Select function XX
Indication on the display:
–  Confirm the entry with Q.
  
Fast data transmission                 Q
Actuator diagnosis
Indication on the display:
When the valve is activated, the sound of the combustion changes notably (pinking).
If no change is noted in the sound of the combustion:
–  Check the regulation margin of the injection corrector → Chapter.
–  Press →.
  
Actuator diagnosis                    ->
Injection start valve N108
Indication on the display:
The valve must chatter.
  Note!
Due to the sound of the engine the chattering of the valve can not be heard and can only be felt by touching the valve.
If the valve fails to chatter:
–  Check the valve for exhaust gas recirculation → Rep. Gr.26.
  
Actuator diagnosis                    ->
Exhaust gas recirc. valve N18
Indication on the display:
It is made sure that the air conditioning compressor turns off.
The test will also appear if the vehicle does not have air conditioning.
The air conditioning compressor must be stopped within 5 seconds (visual examination) and then started every 5 seconds and stopped again.
If the air conditioning compressor does not turn off:
–  Check the signals from/to the air conditioning → Chapter.
–  Press →.
  
Actuator diagnosis                    ->
Intervention of air conditioning
Indication on the display:
When the motor of the inlet manifold plate is activated, the sound of the combustion changes (the motor opens and closes the inlet manifold plate).
If no change is noted in the sound of the combustion:
–  Check the motor for the inlet manifold plate → Chapter.
–  Press →.
  
Actuator diagnosis                    ->
Motor for inlet manifold plate V157
Indication on the display:
The engine should stop.
If the engine fails to stop:
–  Turn off the ignition.
–  Remove the fuel cut valve and clean possible chips or sirt.
–  Repeat the actuator diagnosis: if the engine fails to stop again, replace the fuel cut valve → Chapter.
–  Continue the actuator diagnosis with the engine turned off and the ingition on.
–  Press →.
  
Actuator diagnosis                    ->
Fuel cut valve N109
Indication on the display:
The relay should chatter.
Due to the high current absorption of the glow plugs, when the relay comes on and goes off, it is also noted by the increase or decrease in the interior lighting.
If the relay fails to chatter:
–  Check the relay for the glow plugs → Current flow diagrams, Electrical fault finding and Fitting locations.
–  Press →.
  
Actuator diagnosis                    ->
Relay for glow plugs J52
Indication on the display:
The warning light must blink.
If the warning light fails to blink:
–  Check the preheating time warning light → Current flow diagrams, Electrical fault finding and Fitting locations
–  Press →.
  
Actuator diagnosis                    ->
Preheating time warning light K29
Indication on the display:
The relay should chatter.
If the relay fails to chatter:
–  Check the relay for low calorific power → Current flow diagrams, Electrical fault finding and Fitting locations.
–  Press →.
  
Actuator diagnosis                    ->
Relay low calorific power J359
Indication on the display:
The relay should chatter.
If the relay fails to chatter:
–  Check the relay for high calorific power → Current flow diagrams, Electrical fault finding and Fitting locations.
–  Press →.
  
Actuator diagnosis                    ->
Relay high calorific power J360
Indication on the display:
–  Press the keys 0 and 6 for the function “End data transmission” and confirm with Q.
–  Turn off the ignition.
  
Fast data transmission              HELP
Select function XX

Fuel preparation system Diesel injection > < Actuator diagnosis