Audi Workshop Service and Repair Manuals

Checking turbocharger and charge pressure control - vehicles with plug in intake manifold Special tools and workshop equipment required

t  Adapter -V.A.G 1318/11-

t  Turbocharger tester -V.A.G 1397A-

t  Vehicle diagnostic, testing and information system -VAS 5051B-

Procedure l  Charge pressure is measured under full load while driving or on a roller dynamometer. l  Test duration per measurement: max. 10 seconds –  Unscrew plug -arrow- at intake manifold (front).

–  Screw adapter -V.A.G 1318/11- into hole in intake manifold. –  Connect adapter -V.A.G 1318/11- to hose of turbocharger tester -V.A.G 1397A- using test hoses. –  Route test hose under rear edge of bonnet and through right window into passenger compartment.

–  Switch on turbocharger tester and set measuring range selector switch to position -I- (absolute pressure). –  Attach test hose to connection -I-.   Note t  Ensure absolute leakproof connection of hoses to avoid measurement errors. t  Take care not to trap test hose at bonnet and side window. t  Pressing memory button -M- on turbocharger tester causes last measured value to be stored until memory button -M- is pressed again or tester is switched off. t  The decimal point in the display flashes to indicate that the value is being stored. t  If the battery voltage of the turbocharger tester drops below the minimum level, an arrow will appear at the top left of the display. t  Before performing the test, drive vehicle moderately fast for at least 3 km (without stopping at traffic lights etc.).   WARNING Accidents can be caused if the driver is distracted by test equipment while road-testing, or if test equipment is not properly secured. Observe safety precautions → Chapter. 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 diagnosis function “Measured values” and press → key to continue.

Display on -VAS 5051B-: –  Press keys 11 on keypad -1- to select “Display group 011” and confirm entry by pressing Q key. –  Accelerate vehicle in 3rd gear (or position 2) from 2000 rpm at full throttle while a second mechanic observes the rev counter. –  Have the second mechanic press PRINT key on -VAS 5051B- and memory key -M- on -V.A.G 1397A- simultaneously at approx. 3000 rpm.   Note The charge pressure should be measured using turbocharger tester -V.A.G 1397A-. Vehicle diagnostic, testing and information system -VAS 5051B- is used to check whether the charge pressure is being registered by the control unit.

Display on -V.A.G 1397 A-: l  Specification: 1.960 ... 2.160 bar.

Display on -VAS 5051B-: –  Check display in display zone -3-. l  Specification: 1960 … 2160 mbar. If charge pressure is not within the specified range: –  Check linkage and vacuum unit for charge pressure control → Chapter. –  Check charge pressure control solenoid valve -N75- → Chapter. If both are OK, but the charge pressure is too low: –  Renew turbocharger → Chapter.