Vacuum System, Checking, Except RS 5

Special tools and workshop equipment required

Description and function:

The electrical vacuum pump is switched on by the engine control module depending on the intake line pressure.

The vacuum pump has OBD. Detected faults are stored in engine control module.

NOTE:

The function of the electrical vacuum pump can only be checked using OBD when the engine is switched off.

Procedure

-- Turn off the ignition.

-- Press the brake pedal until there is no more brake assistance - "pump the brake booster empty". The brake pedal becomes hard.

-- Connect the Vehicle Diagnostic Tester to the 16-pin diagnostic socket in the vehicle with the ignition switched off.

-- Switch on tester -arrow-.

Fig 1: Connecting Diagnostic Cable VAS 5051/5A To Diagnostic Connector

Courtesy of AUDI OF AMERICA, LLC

-- Turn on the ignition.

-- Start the appropriate program on the Vehicle Diagnostic Tester.

The ignition must be switched off and onto repeat the test.