S5 Quattro Coupe V8-4.2L (CAUA) (2009)
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Vacuum Pump: Testing and Inspection
Brake System Vacuum Pump, Checking
Description and function
The electrical vacuum pump is switched on by the engine control module depending on the intake line pressure.
Vacuum pump has On Board Diagnostic (OBD) properties. Detected faults are stored in engine control module.
‹› The function of the electrical vacuum pump can only be checked using OBD when the engine is switched off.
Special tools, testers and auxiliary items required
‹› Vehicle diagnosis, testing and information system (VAS 5051).
‹› Diagnostic cable (VAS 5051/1) or diagnostic cable (VAS 5051/3).
Procedure
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Switch ignition off.
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Press brake pedal until there is no more brake assistance - " pump brake booster empty". The brake pedal becomes hard.
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With ignition switched off, connect the vehicle diagnostic, test and information system (VAS 5051) with diagnostic cable (VAS 5051/1) or
diagnostic cable (VAS 5051/3) to the Data Link Connector (DLC).
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Switch on tester - arrow -.
