Audi Workshop Service and Repair Manuals

Testing exhaust gas recirculation function is carried out in function "Basic Setting". Exhaust gas recirculation valve is cycled every 10 seconds during this procedure, so that extreme values for exhaust gas recirculation (air mass meter) can be checked in display group 003.

Special tools, testers and auxiliary equipment required

• ◆ VAS 5051

or

• ◆ V.A.G 1551 with V.A.G 1551/3 A

Test requirements:

• ● Coolant temperature at least 80 °C.

Test sequence

• ‒ Read measured value block, display group 001:

=> Diesel direction-injection and glow lamp system (4-cyl.) 07.97 ä; Repair group 01; Reading measured value block

• ‒ Check display in display zone 4 (coolant temperature).
• ‒ Specified value: at least 80 °C
• ‒ Do not continue with the test until the coolant has reached the specified temperature.
• ‒ Start the basic setting, display group 003:

=> Diesel direction-injection and glow lamp system (4-cyl.) 07.97 ä; Repair group 01; Basic setting

• ‒ Check display in zones 2 and 3.

    1)    Display changes every 10 seconds between "EGR active" and "EGR not active".

Note:

If a constant 550 mg/stroke is displayed in display zone 3, then a jamming mechanical exhaust gas recirculation valve or a defective air mass meter could be the cause. In the latter case, interrogate fault memory whether fault 00553 is stored:

=> Diesel direction-injection and glow lamp system (4-cyl.) 07.97 ä; Repair group 01; Self-diagnosis; Interrogating and erasing fault memory

If the specified values are not obtained:

• ‒ Start final control diagnosis and actuate the EGR valve -N18:

=> Diesel direction-injection and glow lamp system (4-cyl.) 07.97 ä; Repair group 01; Final control diagnosis

• The injector valve should click.

If the injector does not click:

• ‒ Check EGR valve-N18

If the injector clicks:

• ‒ Check vacuum hoses => Page 26-32.

If vacuum hoses are OK:

• ‒ Test mechanical exhaust gas recirculation valve => Page 26-34.