Basic settings for AGR/LDR valves using VCDS. 2.0 TDi, BRE engine

Dear community of DIY enthusiasts,
I have a question about the topic above that I haven't found answered in the community yet.

"Is it absolutely necessary to perform the adaptation or basic setting procedure when replacing an AGR (Abgasrückführungventil) or a turbocharger? If so, does this also apply if the AGR has only been cleaned?"

Does a re-calibration of the charge pressure control system need to be performed when replacing the electro-pneumatic pressure transducer that controls the VTG (variable geometry turbine)?

Is it possible that the engine control unit has, over time, adapted to these components, and that these adaptations now need to be adjusted?

In the basic settings mode of VCDS, under "Exhaust Gas Recirculation," the following prerequisites are listed: Ignition ON / Engine ON (running).

Activate the default setting and press both the brake and accelerator pedals.
The exhaust gas recirculation (EGR) system is now automatically activated and deactivated.
The difference between the active and inactive states must be at least 100.0 mg/port.

Does the accelerator pedal absolutely have to be fully depressed? If so, will VCDS automatically reduce the throttle?

I would appreciate a response.

audifriend

Hi,

No basic settings need to be configured for the BRE.

Best regards, Rainer.

Thank you for the tip, Rainer. I had hoped that the default settings would correct any faulty motor behavior.

For years, my car has occasionally entered "limp mode" on the highway when traveling at speeds around 140 km/h. In this mode, I can continue driving at approximately 100 km/h. VCDS identifies the following error: P0234 - Turbocharger Overboost Condition. Desired boost pressure is 1950 mbar, actual boost pressure is 2480 mbar.

I have disassembled and cleaned the loader several times. There are no apparent issues. The pressure chamber retracts the control rod smoothly, without any jerking. The vacuum system has been checked. The tandem pump produces 800 mbar of vacuum at idle. The electric control valve for the vacuum cylinder of the loader has been replaced.

"The problem could also be caused by excessive back pressure in the exhaust system. The DPF (Diesel Particulate Filter) was removed and cleaned. According to the certificate, 45 grams of ash were removed. The back pressure measurement before cleaning was 62 mbar, and after cleaning it was 5 mbar. Therefore, the issue shouldn't be related to the DPF. I've driven about 1000 km since then."

Damit im Zusammenhang frage ich mich, ob das Abgasendrohr innen mit Ruß belegt sein darf. Das ist der Fall trotz DPF. Could that be possible?
Then I noticed that my car smells like it's blowing out spark plugs when idling.

I have already analyzed several data blocks (3, 10, 11, and 13), but I haven't been able to identify any anomalies. I'm simply at a loss right now.

Best regards,
audifriend

Hi.

Quote:

Fehler könnte auch durch einen zu hohen Abgasgegendruck entstehen.

No. Lader-VTG is usually solid or mechanically difficult to operate.
The BRE system makes it easy to replace the charger, but it's not cheap.

Best regards, Rainer.