Audi Workshop Service and Repair Manuals

Checking turbocharger air recirculation vale -N249- - engine codes ANB, APU, ARK, ATW Special tools and workshop equipment required

t  Hand-held multimeter -V.A.G 1526D-

t  Voltage tester -V.A.G 1527B-

t  Auxiliary measuring set -V.A.G 1594C-

t  Adapter cable, 121-pin -V.A.G 1598/31- t  Vehicle diagnostic, testing and information system -VAS 5051B- Procedure   Note Air recirculation valve for turbocharger -N249- and its wiring are monitored by the engine control unit. l  Vehicle diagnostic, testing and information system -VAS 5051B- connected. l  Engine running. l  Vehicle self-diagnosis and vehicle system “01 - Engine electronics” selected.

Display on -VAS 5051B-: –  From menu -1-, select diagnostic function “Interrogate fault memory” and press → key to continue. If the display shows a fault relating to air recirculation valve for turbocharger -N249-: –  Press ← key to terminate function “Interrogate fault memory”. –  Select “End output”. –  Switch off ignition.

–  Disconnect hoses from turbocharger air recirculation valve -N249--item 1-; leave electrical connector attached. l  Fitting location: below intake manifold   Note The illustration shows the intake manifold from below and removed from the engine.

–  Connect a test hose to the hose connection on the turbocharger air recirculation valve -N249- marked with an -arrow-.

–  Switch on ignition and select vehicle system “01 - Engine electronics” again. Display on -VAS 5051B-: –  From menu -1- select diagnostic function “Final control diagnosis”.

–  Press the → key repeatedly until the following display appears: Display on -VAS 5051B-: 6 -  Turbocharger air recirculation valve -N249- A -  Actuator is running; continued switching is allowed l  The valve will be activated intermittently for approx. 1 minute (and should click audibly). l  The valve should open and close (check by blowing into the test hose). –  Press ← key to terminate diagnostic function “Final control diagnosis”. –  Select function “End output” and switch off ignition. If valve clicks but does not open or close correctly: –  Renew air recirculation valve for turbocharger -N249-. If valve does not click:

Checking internal resistance –  Unplug electrical connector at turbocharger air recirculation valve -N249--item 1-.

–  Connect hand-held multimeter -V.A.G 1526D- to valve (resistance measurement range). l  Specification: 27 ... 30 Ω. –  If reading does not match specification, renew turbocharger air recirculation valve -N249-. If the specification is attained: Checking voltage supply l  Fuse for turbocharger air recirculation valve -N249- OK → Current flow diagrams, Electrical fault finding and Fitting locations. l  Fuel pump relay -J17- OK → Rep. Gr.24.   Note Turbocharger air recirculation valve -N249- is supplied with power via fuel pump relay -J17-.

–  Connect voltage tester -V.A.G 1527B- between contact -1- of connector for turbocharger air recirculation valve -N249- and earth “–”. –  Briefly operate starter. l  The LED should light up. –  If LED does not light up, check for open circuit in wiring from contact -1- of connector for turbocharger air recirculation valve -N249- via fuse to fuel pump relay -J17- → Current flow diagrams, Electrical fault finding and Fitting locations. –  Repair wiring connection if necessary. If the LED lights up:

Checking activation –  Connect voltage tester -V.A.G 1527B- between contact -1- and -2- of connector for turbocharger air recirculation valve -N249-.

–  Switch on ignition and select vehicle system “01 - Engine electronics”. –  Repeat diagnostic function “Final control diagnosis”. –  Press the → key repeatedly until the following display appears: Display on -VAS 5051B-: 6 -  Turbocharger air recirculation valve -N249- A -  Actuator is running; continued switching is allowed l  The LED should flash. –  Press ← key to terminate diagnostic function “Final control diagnosis”. –  Select “End output”. –  Switch off ignition and unplug diagnostic connector.

–  If LED does not flash or lights up continuously, connect adapter cable, 121-pin -V.A.G 1598/31- (test box) to connectors of wiring harness; do not connect engine control unit. Connect earth clip of test box to earth → Rep. Gr.24.   Caution Electronic components are susceptible to damage. Select the appropriate measuring range before connecting the test leads and observe test requirements.

–  Check for open circuit and short to positive or earth in the following wiring for turbocharger air recirculation valve -N249-.

Connector Contact	-V.A.G 1598/31- Socket
-2-	105

–  Repair wiring connection if necessary.