S6 V8-4.2L (BBD) (2004)
Variable Induction Control Valve: Testing and Inspection
With Manufacturer's Scan Tool
Intake manifold change-over valve - N156-, checking
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Run engine at idling speed for 2 or 3 minutes to build up vacuum pressure.
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Switch engine off.
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Switch ignition on.
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Perform output Diagnostic Test Mode and actuate intake manifold change-over valve. See: Computers and Control Systems/Testing and
Inspection/Scan Tool Testing and Procedures/Scan Tool Testing/With Manufacturer's Scan Tool/Output Diagnostic Test Mode (DTM) (Function
03)
Indicated on display
Output Diagnostic Test Mode
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Intake manifold change-over valve -N156-
Valve should click (clicking can be heard and felt). After 1 minute output DTM is terminated.
If solenoid valve does not click:
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Switch ignition off.
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Disconnect connector from relevant solenoid valve for intake manifold change-over.
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Measure resistance between contacts on solenoid valve using VAG 1526.
Specified value: 25...35 Ohms
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If measured value is not as specified, replace solenoid valve for intake manifold change-over.
If the specified value is achieved, check the voltage supply.
Checking voltage supply of intake manifold change-over valve
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Connect diode test lamp V.A.G 1527 between engine Ground and socket 1 (positive) on connector using cables from adapter set VAG 1594.
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Operate starter briefly.
Diode test lamp should illuminate.
If the diode test lamp does not illuminate:
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Check fuse for solenoid valve for intake manifold change-over.