Audi Workshop Service and Repair Manuals

The functioning of the exhaust gas recirculation system is checked in the "Basic setting" function. This procedure samples the EGR valve every 10 seconds, so the extreme values for the EGR system (air-mass meter) can be read from display group 003.

Special tools and workshop equipment required

• ◆ VAS 5051 with VAS 5051/1

Test requirements:

• ● Engine must be idling.
• ● Vehicle diagnostic, testing and information system VAS 5051 connected; vehicle self-diagnosis and vehicle system "01 - Engine electronics" selected
• ● Coolant temperature at least 80 °C

Test sequence

→ Readout on VAS 5051:

• ‒ Enter diagnostic function "04 - Basic setting" in selection -1-.

→ Readout on VAS 5051:

•     1 -    Enter display group
  max. input value = 255

• ‒ Use keypad-2- to enter "003" for "Display group number 03" and confirm by touching Q key.

• ◆ The idle speed is increased to 1380 ... 1420 rpm

→ Readout on VAS 5051:

• ‒ Check readout in display zone -2-.
• ‒ Specification: "EGR n.active" and "EGR active" alternating every 10 seconds
• ‒ Check readout in display zone -3-.
• ‒ Specification: Intake air mass readout "... mg/H" must change substantially every 10 seconds
• ‒ Check readout in display zone -4-.
• ‒ Specification: Intake air mass readout "... mg/H" must change substantially every 10 seconds

If readings do not match specifications:

• ‒ Check mechanical EGR valve => Page 26-35.
• ‒ Check vacuum hoses => Page 26-33.
• ‒ Check EGR valve -N18 => Page 26-41.

• ‒ End function "04 - Basic setting" by pressing ◂ key.

→ Readout on VAS 5051:

• ‒ Enter diagnostic function "06 - End output" in selection -1-.