Vacuum diaphragm for boost pressure regulator valve, checking

Special tools, testers and auxiliary items required 

• Fault Read Out Device V.A.G 1551 or Vehicle Diagnosis, Testing and Information System VAS 5051B

Test conditions 

• Engine oil temperature at least 60 ° C
• No leaks on intake or exhaust side.

Test sequence 

Fig 1: Identifying Connector At Wastegate Bypass Regulator Valve N75

Courtesy of VOLKSWAGEN UNITED STATES, INC.

• Disconnect connector - 2  - at Wastegate Bypass Regulator Valve N75 - 1  -.

Fig 2: Boost Pressure Regulator Valve And Actuator Rod

Courtesy of VOLKSWAGEN UNITED STATES, INC.

• Start engine and increase speed to maximum RPM by depressing accelerator pedal suddenly. Actuator rod - 2  - for boost pressure regulator valve must move.

If actuator rod does not move:

• Check lever for boost pressure regulator valve - 1  - for ease of movement. If rusted in place, replace turbocharger.

If actuator rod does not move through light prying:

• Exhaust turbocharger faulty, replace it, refer to Turbocharger with attachments, assembly overview  .
• Check DTC memory.
• Read readiness code.
• If DTC memory was cleared or engine control module disconnected from voltage supply, readiness code must be regenerated.