Audi Workshop Service and Repair Manuals

Checking exhaust gas recirculation The exhaust gas recirculation function is checked with the vehicle diagnosis, testing and information system -VAS 5051B- in the “Basic setting” mode. In this test, the EGR valve is pulsed every 10 seconds, so that the extreme values for the EGR (air mass meter -G70-) can be read off. Special tools and workshop equipment required

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

Procedure l  Coolant temperature at least 80 °C. –  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 diagnosis function “006 - Basic setting” and press → key to activate function.

Display on -VAS 5051B-: –  Press key 3 on keypad -1- to select “Display group 003” and confirm entry by pressing key Q.

Display on -VAS 5051B-: –  Activate basic setting by touching key Activate. l  The idling speed is increased to 1350 rpm ... 1450 rpm. –  Check information shown in display zones -2, 3, 4-. –  Press “Print - Save result” on -VAS 5051B-.

Display zone	Readout	Specification
-2-	Activation of exhaust gas recirculation valve -N18-	Display alternates at 10 second intervals: “EGR active” and “EGR inactive”
-3-	Intake air mass	Display alternates at 10 second intervals: Difference min. 100 mg/H
-4-	Duty cycle of exhaust gas recirculation valve -N18-	Display alternates at 10 second intervals: “20 %” and “65 %”

–  End function “006 - Basic setting” by pressing ← key. –  Press “022 - End output”. –  Switch off ignition. If the specifications are not obtained: –  Check mechanical exhaust gas recirculation valve  → Chapter. –  Check vacuum hose connections  → Chapter. –  Check exhaust gas recirculation valve -N18- → Vehicle diagnosis, testing and information system VAS 5051.