Variable Induction System: Testing and Inspection

Intake manifold change-over, checking

The first stage of the intake manifold changeover is omitted with all S6 models.

Only perform the test when there is a lack in performance or a DTC was registered.

The change-over of the intake manifold from the long to the short intake path is dependent on speed.

Intake manifold change-over, function

- Connect vehicle diagnostic, testing and information system VAS 5051 or V.A.G 1551 Scan Tool and select engine electronics control unit 1 with "Address word" 01. For this purpose, engine must be running at idle speed.

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 08
Enter display group number XXX

- Press keys 0, 9 and 5 for "display group number 95" and confirm entry with Q key.

Indicated on display
Read measured value block 95 ->
1 2 3 4

- Check display values for intake manifold change-over.

Display Group 95:

- Check display in display zone 4.
Specified value: "IMC-V OFF"






Specification for display zone 4:
"IMC-V OFF" vacuum units tightened

- Increase engine speed to approx. 5400 rpm to initiate intake manifold change-over.

Display Group 95:

- Check whether vacuum units are actuated.






If "SU-V ON" is displayed but the intake manifold change-over is not initiated (vacuum units must not be actuated) check the following component:

- Check solenoid valves for intake manifold change-over. Intake Change-Over -N156- & Tuning (IMT) Valve 2 -N261-