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Vacuum plan for exhaust gas recirculation without intake manifold flap - engine code AGR > < Testing exhaust gas recirculation valve

A3 Mk1

Diesel Direct Injection and Glow Plug System (TDI 4 cyl.) >07.99
Checking exhaust gas recirculation system
Testing air mass meter

The signal from the air mass meter is required by the control unit to calculate the required injection quantity and to control the exhaust gas recirculation. The weaker the signal from the mass air flow meter, the less fuel can be injected.

Important:
Second person is required to operate V.A.G 1551.
  • ‒ Read measured value block, display group 10, Engine idling
 
→ Indicated on display:
Read measured value block 10    ⇒
    309 mg/stroke    1030 mbar    1011 mbar    0.0 %
  • ‒ Observe readout in display zone 1.
 
→ Specification: 230...370 mg/stroke
Read measured value block 10    ⇒
    309 mg/stroke    1030 mbar    1011 mbar    0.0 %

If specified value is not attained:

  • ‒ Check exhaust gas recirculation system

If specified value is attained:

  • ‒ Accelerate vehicle in 3rd gear from about 1500 rpm using full throttle.
  • ‒ Press PRINT key on V.A.G 1551 at about 3000 rpm.
 
→ Specification for display zone 4: 100 % (accelerator pedal position)
Read measured value block 10    ⇒
    830 mg/stroke    1030 mbar    1850 mbar    100 %

If specified value is not attained:

  • ‒ Repeat test and accelerate vehicle at full throttle.
 
→ Specification for display zone 3: 1800...2050 mbar (boost pressure)
Read measured value block 10    ⇒
    830 mg/stroke    1030 mbar    1850 mbar    100 %

If specified value is not attained:

  • ‒ Check boost pressure => Page 23-43
 
→ Specification for display zone 1: >750 mg/stroke (intake air mass)
Read measured value block 10    ⇒
    830 mg/stroke    1030 mbar    1850 mbar    100 %

If specified value is not attained:

  • ‒ Replace air mass meter (G70).

If display zone 1 shows a constant reading of 425 mg/stroke (fixed substitute value):

  • ‒ Switch ignition off.
  • ‒ Remove connector from air mass meter =>Fitting location overview, Page 23-3
  • ‒ Switch the ignition on.
 
N23-0017
  • ‒ → Connect the multimeter for voltage measurement to the following contacts on the connector:

6-pin connector on wiring harness, contact

Specified value

3 + earth

Battery voltage

3 + 5

Battery voltage

1 + earth

approx. 5 V

1 + 5

approx. 5 V

If specified values are not attained:

  • ‒ Connect test box V.A.G 1598/22 to wiring harness for engine control unit .
 
N23-0017

The following wiring connections are to be checked for open circuits and/or short to positive or negative.

6-pin connector on the wiring harness, contact.

Test box V.A.G 1598/22, socket

1

50

2

25

3

2, 28

4

-

5

1, 27

6

52
  • ‒ Rectify any open/short circuit as necessary.

Vacuum plan for exhaust gas recirculation without intake manifold flap - engine code AGR > < Testing exhaust gas recirculation valve