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Testing intake manifold change-over valve -N156 > < Testing intake manifold change-over function

A4 Mk1

Motronic injection and ignition system (4-cyl.)
Testing intake manifold change-over function
Testing operation
  • ‒ Connect vehicle diagnostic, testing and information system VAS 5051 (or fault reader V.A.G 1551) and select engine electronics control unit by entering address word "01" ( .)
    When doing this the engine must be idling.
 
→ Indicated on display:
Rapid data transfer    HELP
Select function XX
  • ‒ Press keys 0 and 8 for the function "Read measured value block" and confirm entry with Q key.
 
→ Indicated on display:
Read measured value block    
Enter display group number XXX
  • ‒ Press keys 0, 9 and 5 for Display Group 95 and confirm entry with the Q key.
 
→ Indicated on display:
Read measured value block 95    ⇒
    1    2    3    4
  • ‒ Check display values for intake manifold change-over.

Display zones

1

2

3

4

Display Group 95: Intake manifold change-over at idling speed

Display

xxx rpm

x.xx %

xxx.x ° C

IMC-V OFF

Indicates

Engine speed
(in steps of 40 rpm)

Load

Coolant temperature

Intake manifold change-over

Range

min.: 750 rpm
max.: 6800 rpm

min.: 0.00 %
max.: 120.00 %

IMC-V OFF
IMC-V ON

Specification

810...910 rpm

15.0....25.0 %

80.0...105.0 ° C

IMC-V OFF

Note

  • ‒ Check readout in display zone 4.
  • Specification: IMC-V OFF
  • ‒ Floor and release the accelerator quickly (short blip).
  • ‒ The intake manifold change-over function should be activated (display zone 4).

Display zones

1

2

3

4

Display Group 95: Intake manifold change-over with vehicle being driven

Display

xxxx rpm

x.xx %

xxx.x ° C

IMC-V ON

Indicates

Engine speed
(in steps of 40 rpm)

Load

Coolant temperature

Intake manifold change-over

Range

min.: 750 rpm
max.: 6800 rpm

min.: 0.00 %
max.: 120.00 %

IMC-V OFF
IMC-V ON

Specification

4500...6680 rpm

15.0...120.00 %

80.0...105.0 ° C

IMC-V ON

Note

Observe change-over function at vacuum unit (located at front left of intake manifold)

If the display shows "IMC-V ON" but the vacuum unit for the intake manifold change-over function is not activated, test the following components:

    • ‒ Test intake manifold change-over valve
      => Page 24-123.
    • ‒ Check vacuum system for leaks
      => Page 24-128

Testing intake manifold change-over valve -N156 > < Testing intake manifold change-over function