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Exhaust system > < Charge air cooling
Removing and installing turbocharger control unit 1J724
Removing and installing turbocharger control unit 1 -J724-
Special tools and workshop equipment required
t  Tester for E-positioner -VAS 6395- or -VAS 6395A-
t  Bracket -VAS 6395 /6-
   
Removing
–  Remove engine cover panel -arrows-.
  A10-11504
–  Lift off cover -1- by its handle.
  A27-10221
–  Release retainer -arrow A- and open cover -arrow B-.
  A10-10851
–  Connect tester -VAS 6395 A/1- with connection lead -VAS 6395/2- to positive terminal -1- and negative terminal -2-.
  A27-10109
Procedure for tester for E-positioner -VAS 6395 A/1-:
–  Select software version with buttons -item 5- and -item 6-.
–  To confirm software version, press v button -item 4-.
  Note
In this example, software version Hella -item 1- is selected.
  A21-10601
Procedure for tester for E-positioner -VAS 6395 /1-:
Checking software version of tester -VAS 6395 /1-:
  Caution
Risk of damage to turbocharger 1 control unit -J724-.
Before continuing, check whether the correct software version is loaded in the tester -VAS 6395 /1-. To do so, proceed as follows:
Display on -VAS 6395 /1- (2 seconds after connecting to power supply) if correct software version is loaded:
1 - > 1. START
2 -  2. NEXT [>]
  Note
t  If the following appears on the display, an incorrect software version has been loaded:
t  1. >TEST
t  2. LEARN
t  If this is the case, download the correct software version from the „Audi ServiceNet“ under „Workshop Equipment“.
  A21-10171
Continuation for both testers:
–  Unplug electrical connector for turbocharger 1 control unit -J724-.
–  Connect connection lead -VAS 6395/2- to turbocharger 1 control unit -J724- and to tester -VAS 6395 A/1-.
  A21-10465
Display on -VAS 6395 A/1-:
1 - > 1. START
2 -  2. NEXT [>]
–  To continue, press v button -item 4-.
l  The tester -VAS 6395 A/1- runs through the adjustment range of the turbocharger 1 control unit -J724- and checks that the end positions are reached; display indicates „CHECK“.
  A21-10601
Display on -VAS 6395 A/1-:
1 - 
2 - [OK]
  Note
t  If the display indicates „[OK]“, the adjustment range of the turbocharger 1 control unit -J724- is OK.
t  If the display shows „FAULT [OK]“, tap gently several times on the housing of turbocharger 1 control unit -J724- with the handle of a screwdriver and repeat the check by pressing v button -item 4-.
  A21-10601
–  Remove bolt -arrow-.
  Note
Do NOT unscrew any of the other bolts visible in the illustration.
  A21-10452
–  Fit bracket -VAS 6395 /6- on centring hole of bracket for turbocharger 1 control unit -J724- and tighten bolt to 8 Nm.
  A21-10453
–  To continue, press v button -item 4-.
l  The turbocharger 1 control unit -J724- moves back and forth between the stops several times to determine the voltage value.
l  Then the turbocharger 1 control unit -J724- moves into installation position.
–  While the voltage value is being determined, keep tapping gently on the housing of turbocharger 1 control unit -J724- until the display indicates the following:
Display on -VAS 6395 A/1-:
1 - X.XXX V
2 - [↑][↓][OK]
–  Note voltage value.
l  Specification: 3.3 ... 3.7 V
  Note
If the display indicates „FAULT [OK]“ or the voltage is less than 3.3 V or greater than 3.7 V, unplug tester -VAS 6395 A/1- and repeat the complete procedure → Anchor.
  A21-10601
Display on -VAS 6395 A/1-:
1 - X.XXX V
2 - [↑][↓][OK]
–  By pressing buttons -item 5- and -item 6-, adjust turbocharger 1 control unit -J724- so that coupling rod can be accessed easily for removal.
  A21-10601
–  Unclip circlips -arrows- and dispose of them, detach coupling rod.
  A21-10283
Display on -VAS 6395 A/1-:
1 - X.XXX V
2 - [↑][↓][OK]
–  By pressing buttons -item 5- and -item 6-, adjust turbocharger 1 control unit -J724- so that bolts for -J724- can be accessed easily.
  A21-10601
–  Disconnect connection lead -VAS 6395/2- from turbocharger 1 control unit -J724-.
  Caution
Power supply for tester -VAS 6395 /1A- must remain connected.
  A21-10465
–  Remove bolts -1, 2, 3- and dispose of them.
  Note
Do NOT unscrew any of the other bolts visible in the illustration.
–  Remove old turbocharger 1 control unit -J724- and dispose of it.
  Caution
Check that the three insulating washers are fitted between turbocharger 1 control unit -J724- and the bracket.
–  Install new turbocharger 1 control unit -J724- in reverse sequence of removal.
–  Fit new bolts as follows:
1 - M6x15 with tapered shank
2 - M6x15 with tapered shank
3 - M6x15
–  Initially hand-tighten bolts.
l  Turbocharger 1 control unit -J724- must rest on retaining plate so there is no play; it must still be possible to move control unit by hand.
  A21-10594
–  Connect connection lead -VAS 6395/2- to new turbocharger 1 control unit -J724-.
  A21-10465
–  To continue, press v button -item 4-.
Display on -VAS 6395 A/1-:
1 - > 1. START
2 - 2. NEXT [>]
–  Select menu item „NEXT“ with button -item 6-.
  A21-10601
–  To continue, press v button -item 4-.
l  The tester -VAS 6395 A/1- runs through the adjustment range of the turbocharger 1 control unit -J724- and checks that the end positions are reached; display indicates „CHECK“.
Display on -VAS 6395 A/1-:
1 - X.XXX V
2 - [OK]
  Note
If the display indicates „FAULT“, the new turbocharger 1 control unit -J724- must be renewed for a second time.
  A21-10601
–  To continue, press v button -item 4-.
Display on -VAS 6395 A/1-:
1 - 
2 - [OK]
  A21-10601
–  To continue, press v button -item 4-.
Display on -VAS 6395 A/1-:
1 - X.XXX V (voltage determined with first measurement)
2 - [OK]
l  Turbocharger 1 control unit -J724- moves into installation position.
  A21-10601
–  Insert coupling rod.
l  Installation position: The thicker eyelet is fitted onto the shaft of turbocharger 1 control unit -J724-.
–  Fit circlips -arrows-.
l  The circlips must engage audibly.
  A21-10283
–  Press turbocharger 1 control unit -J724- towards the rear without applying force -arrow- until lever -1- rests lightly on bracket -VAS 6395/6-.
–  Hold -J724- in this position.
  A21-10592
–  Tighten bolts -1, 2, 3- to 5 Nm.
  A21-10593
–  To continue, press v button -item 4-.
l  Turbocharger 1 control unit -J724- moves back and forth between the stops several times and is adjusted to the voltage value determined with the first measurement.
Display on -VAS 6395 A/1-:
1 - X.XXX V (voltage determined with first measurement)
2 - [OK]
  Note
t  If [OK] is indicated on display, terminate adjustment → Anchor.
t  If „CHECK“ is indicated on display, proceed as follows.
  A21-10601
Procedure if display indicates „CHECK“:
Display on -VAS 6395 A/1-:
1 - [<<<]
2 - CHECK
or
1 - [>>>]
2 - CHECK
  A21-10601
–  Loosen bolts -1, 2, 3- until turbocharger 1 control unit -J724- can just be moved by applying light force in the direction stated:
l  If display indicates [<<<], move -J724- slightly in direction of travel.
l  If display indicates [>>>], move -J724- slightly towards rear of vehicle.
–  Tighten bolts -1, 2, 3- to 5 Nm.
  A21-10593
–  To continue, press v button -item 4-.
l  Turbocharger 1 control unit -J724- again moves back and forth between the stops several times and is adjusted to the voltage value determined with the first measurement.
Display on -VAS 6395 A/1-:
1 - X.XXX V
2 - [OK]
  A21-10601
Terminating adjustment:
–  Tighten bolts -1, 2, 3- to 10 Nm.
  A21-10593
–  To continue, press v button -item 4-.
Display on -VAS 6395 A/1-:
1 - X.XXX V
2 - [OK]
  A21-10601
–  Unbolt bracket -VAS 6395/6--arrow-.
  A21-10453
–  To continue, press v button -item 4-.
l  Turbocharger 1 control unit -J724- moves to end positions.
  Note
If the display indicates „FAULT“, the new turbocharger 1 control unit -J724- must be renewed → Anchor.
Display on -VAS 6395 A/1-:
1 - 
2 - [OK]
l  Adjustment is completed.
–  Unplug electrical connectors for tester -VAS 6395 A/1-.
Assemble in reverse order.
  A21-10601

Exhaust system > < Charge air cooling