Audi A6 3.0 V6 TDI BMK - Turbocharger boost pressure limit exceeded

Hello everyone,

Perhaps you can help me with something...

I'm having a problem with the following vehicle:

Audi A6 3.0 V6 TDI with engine code BMK, manufactured in February 2005, with a mileage of 116,000 km.

During the drive, the engine check light came on, and the vehicle lost power.

The following error is stored in the EDC's error memory:

16619 - Charge pressure control: Limit exceeded.
P0235 - 001 - Upper limit exceeded - Warning light ON.
Environmental conditions:
Speed: 2058 RPM
Torque: 335.4 Nm
Speed: 67.2 km/h
Pressure: 1805.4 mbar.
Pressure: 1356.6 mbar
Air mass/Hub: 652.1 mg/H
Temperature: 20.7 °C
Key press ratio: 59.6%

After removing the engine cover, I checked the VTG linkage using the actuator diagnostic function, and it is working correctly.

Both intake manifold flap control systems are functioning correctly.

Please provide assistance.


Best regards.

Markus.

Hello,

Quote:

Pressure: 1805.4 mbar. Pressure: 1356.6 mbar. Air mass/Flow rate: 652.1 mg/H

The air mass value can be determined from the actual intake manifold pressure of 1356.6 mbar and the target value of 1805.4 mbar.

Since the target value is not being reached, the following points should be checked:
- Intercooler leak.
- AGR valve defective/stuck.
- VTG function is faulty. Actuator or turbocharger malfunction.

Sure, here's the translation:

"VG, Rainer" translates to "Best regards, Rainer" or "Regards, Rainer" in English.

Thank you for the quick response.

After checking the Vtg (actuator diagnosis) using VCDS.
I exclude these. It moves smoothly and travels from stop to stop.

The agricultural sector is also under immense pressure, and all systems are operating at maximum capacity.

As far as I can tell, there shouldn't be any issues with the intercooler, as there's no black smoke coming from the exhaust and no 'whistling' sound during driving.

I understand the issue with the air mass; it's a consequence of a 'fault' that prevents the necessary boost pressure from being generated.

Could it be that there is a problem on the diesel side?

No fuel, no boost?

Best regards.

Markus.

Yes, that exists too. If the nozzles are completely clogged with carbon deposits, the exhaust will remain relatively cool and will also have less volume.
You can find more information in the MWB guidelines, sections 72 and following. A "+" indicates a tendency towards coking, while a "-" indicates a tendency towards leakage.
Or the Lambda values at full load, I don't have the MWB value in my head right now.