Audi Workshop Service and Repair Manuals

Checking charge pressure Special tools and workshop equipment required

t  Vehicle diagnosis, testing and information system -VAS 5051- Procedure l  All hoses, pipes and wiring are checked for tight fit and leakages. l  No leaks in the intake and exhaust systems. l  No faults on engine or injection system (e.g. compression pressure or injector units). l  Coolant temperature at least 80 °C. l  Fault memory interrogated.   WARNING To avoid accident risks when road testing the vehicle with test equipment, always observe the relevant safety precautions → Chapter.

–  Start the engine and run at idling speed. –  Connect up the vehicle diagnostic, testing and information system -VAS 5051B-.

Display on -VAS 5051B-: –  From menu -1-, select “Self diagnosis” system and press → key to activate function.

Display on -VAS 5051B-: –  From menu -1-, select vehicle system “01 - Engine electronics” system and press → key to activate function.

Display on -VAS 5051B-: –  From menu -1-, select function “010 - Read measured values” and press → key to activate function.

Display on -VAS 5051B-: –  Press keys 11 on keypad -1- to select “Display group 11” and confirm entry by pressing key Q.

Display on -VAS 5051B-: –  Accelerate vehicle in 3rd gear from 2000 rpm at full throttle and observe rev counter. –  Press “Print - Save result” on -VAS 5051B- at approx. 3000 rpm.

Display zone	Readout	Specification for engine code AMF, BHC	Specification for engine code ATL
-1-	Engine speed	2800 ... 3200 rpm	2800 ... 3200 rpm
-2-	Specification (charge pressure)	1800 ... 2100 mbar	2100 ... 2400 mbar
-3-	Actual (charge pressure)	1700 ... 2200 mbar	2000 ... 2500 mbar
-4-	Signal ratio of charge pressure control solenoid valve -N75-	…  %	…  %

–  Exit function “010 - Read measured value block” by pressing the ← key. –  Press “022 - End output”. –  Switch off ignition. If charge pressure in display zone -3- is not within the specified range: –  Check charge air system for leaks. –  Check charge pressure control solenoid valve -N75- → Vehicle diagnosis, testing and information system VAS 5051. If all the above items are OK, but the charge pressure is too low: –  Renew turbocharger → Chapter „Removing and installing turbocharger - vehicles with engine code letters AMF“ or → Chapter „Removing and installing turbocharger - vehicles with engine code letters ATL, BHC“.