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Ignition system, glow plug system > < Wiring and component check with test box V.A.G 1598/31

A2

Renewing diesel direct injection system control unitJ248
Renewing diesel direct injection system control unit -J248-
  Note
t  Depending on which auxiliary air heater element -Z35- (version with 900 or 1500 Watt) is installed, different engine control unit versions are fitted.
t  When the engine control unit is disconnected, the learnt values are erased but the contents of the fault memory remain intact.
Removing engine control unit
–  Connect vehicle diagnosis and service information system -VAS 5052- and select engine electronics control unit by entering “address word” 01. When doing this, the ignition must be switched on.
   
The display on vehicle diagnosis and service information system -VAS 5052- will show the control unit identification and the coding -2-.
–  Always start by displaying the control unit identification and printing it out.
–  Switch off ignition.
–  Lift the floor covering from the left footwell → Rep. Gr.70; Removing and installing floor covering.
  A87-0314
–  Release retaining bolts -arrow- on cover.
–  Detach cover.
–  Remove fuse holder -3-.
  A24-0374
–  Loosen bolts -arrow- and carefully remove control unit support.
–  Carefully take out engine control unit -1- (push the retaining clips -4- in direction of arrow) -see next illustration-.
  A24-0376
Retaining clip for engine control unit:
–  Release connectors on engine control unit and unplug connectors.
Installing engine control unit
Installation is performed in the reverse sequence.
–  Perform adaption of immobiliser to diesel direct injection system control unit -J248- (otherwise vehicle will not start)
–  Perform coding of new engine control unit.
–  On vehicles with cruise control system (identifiable by controls on steering column), activate the cruise control system via the engine control unit.
t  For this purpose, use vehicle diagnosis and service information system -VAS 5052-.
–  Select “Go to” button, “Function/component selection”, “Powertrain”, “Engine code”, “01 Self-diagnosis systems”, “Functions”, “J248 23 CU for diesel direct injection system” and “Renewing engine control unit” in the “Guided Fault Finding”.
The following step is only required on vehicles with automated manual gearbox 085 DS:
–  Perform a basic setting for clutch travel sender -G162- located on slave cylinder.
t  5-speed manual gearbox 085 DS, Self-diagnosis → Rep. Gr.01; Starting basic setting.
  A24-0373

Ignition system, glow plug system > < Wiring and component check with test box V.A.G 1598/31