Exhaust Pressure Regulator: Testing and Inspection

Exhaust Flaps, Checking

Special tools, testers and auxiliary items required

• Vehicle Diagnostic, Testing and Information System (VAS 5051 A) with diagnostic cable (VAS 5051/5A)

Test Sequence

• Vehicle Diagnostic, Testing and Information System (VAS 5051 A) with diagnostic cable (VAS 5051/5A) is connected.





- Let engine run briefly so that the required vacuum for the test is present in vacuum reservoir.

- Switch engine off and then switch ignition on.

- Select vehicle On Board Diagnostics and vehicle system "01 - Engine electronics".

Display on (VAS 5051 A):





- In selection - 1 -, click on the function "03 - output Diagnostic Test Mode (DTM)".

- Press -> button repeatedly until Exhaust Flap Valve 1 (N321) is activated.





• The actuation rod of the right exhaust flap must move itself on and off.

- End function "03 - output Diagnostic Test Mode (DTM)" by pressing <- button.

- Select "06 - End Output".

- Select vehicle system "11 - Engine electronics II".

Display on (VAS 5051 A):





- In selection - 1 -, click on the function "03 - output Diagnostic Test Mode (DTM)".

- Press -> button repeatedly until Exhaust Flap Valve 2 (N322) is activated.





• The actuation rod of the left exhaust flap must move itself on and off.

- End function "03 - output Diagnostic Test Mode (DTM)" by pressing <- button.

- Select "06 - End Output".

- Switch off ignition.

If actuator rod does not move:

- Check exhaust flap vacuum reservoir => [ Exhaust Flap Vacuum Diaphragm, Checking ] Testing and Inspection.

- Check vacuum line from vacuum reservoir to the corresponding exhaust flap valve at rear on vehicle floor.

- Check Exhaust Flap Valve 1 (N321) and (N322) using the VAS 5051/5052 "Guided Fault Finding" Function.