Audi Workshop Service and Repair Manuals

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  Connection lead -VAS 6395 /2- t  Bracket -VAS 6395 /5-

Removing –  Remove engine cover panel -arrows-.

–  Unplug electrical connector -1- for exhaust gas temperature sender and move wiring clear. –  Remove bolts -2- and -3-.   Note The bottom bolt -3- does not have to be removed completely. –  Detach heat shield for turbocharger.

–  Vehicles with three-piece plenum chamber cover: Unclip centre part -2- and detach.   Note Disregard -items 1, 3- and -arrow-.

–  Vehicles with one-piece plenum chamber cover: Lift cover -1- by its handle.

–  Release retainer -arrow A- and open cover -arrow B-.

–  Connect tester -VAS 6395 /1A- with connection lead -VAS 6395/2- to positive terminal -1- and negative terminal -2-.

Procedure for tester for E-positioner -VAS 6395 /1A-: –  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.

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“.

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 /1A-.

Display on -VAS 6395 /1A-: 1 -  > 1. START 2 -  2. NEXT [>] –  To continue, press v button -item 4-. l  The tester -VAS 6395 /1A- 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 /1A-: 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-.

–  Secure bracket -VAS 6395/5- with countersunk bolts supplied with and screwed into bracket (8 Nm).   Caution Measurement errors due to incorrect attachment of bracket -VAS 6395/5-. t  The bracket should only be bolted on using the countersunk bolts supplied with the bracket. t  The bracket must not be loosened until the work sequence has been completed.

–  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 /1A-: 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 /1A- and repeat the complete procedure → Anchor.

Display on -VAS 6395 /1A-: 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.

–  Unclip circlips -arrows- and dispose of them, detach coupling rod.

Display on -VAS 6395 /1A-: 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.

–  Disconnect connection lead -VAS 6395/2- from turbocharger 1 control unit -J724-.   Caution Power supply for tester -VAS 6395 /1A- must remain connected.

–  Remove bolts -1, 2, 3- and dispose of them. –  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.

–  Connect connection lead -VAS 6395/2- to new turbocharger 1 control unit -J724-.

–  To continue, press v button -item 4-. Display on -VAS 6395 /1A-: 1 -  > 1. START 2 -  2. NEXT [>] –  Select menu item „NEXT“ with ↓ button -item 6-.

–  To continue, press v button -item 4-. l  The tester -VAS 6395 /1A- 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 /1A-: 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.

–  To continue, press v button -item 4-. Display on -VAS 6395 /1A-: 1 -  2 -  [OK]

–  To continue, press v button -item 4-. Display on -VAS 6395 /1A-: 1 -  X.XXX V (voltage determined with first measurement) 2 -  [OK] l  Turbocharger 1 control unit -J724- moves into installation position.

–  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.

–  Press turbocharger 1 control unit -J724- towards the rear without applying force -arrow- until lever -1- rests lightly on bracket -VAS 6395/5-. –  Hold -J724- in this position.

–  Tighten bolts -1, 2, 3- to 5 Nm.

–  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 /1A-: 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.

Procedure if display indicates „CHECK“: Display on -VAS 6395 /1A-: 1 -  [<<<] 2 -  CHECK or 1 -  [>>>] 2 -  CHECK

–  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.

–  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 /1A-: 1 -  X.XXX V 2 -  [OK]

Terminating adjustment: –  Tighten bolts -1, 2, 3- to 10 Nm.

–  To continue, press v button -item 4-. Display on -VAS 6395 /1A-: 1 -  X.XXX V 2 -  [OK]

–  Unbolt bracket -VAS 6395/5-.

–  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 /1A-: 1 -  2 -  [OK] l  Adjustment is completed. –  Unplug electrical connectors for tester -VAS 6395 /1A-. Assemble in reverse order.