MWB 3/AGR: Meaning of Duty Cycle Ratio

Hello!

Here's a question about the meaning of MWB 3, specifically regarding the EGR duty cycle. Consider a 1.9 TDI engine with an active EGR system. At idle, a value of 10-90% might be displayed, which corresponds to the EGR valve being more or less open. Under full load, the value drops to 4-5%, indicating that the valve is closed.

I took the opportunity to read out various data points from a seemingly "healthy" V6 TDI engine belonging to an acquaintance. At idle, I see an EGR valve duty cycle of 40-45%. However, when accelerating or under full load, this value doesn't decrease to 4-5%, as it does with the 1.9 TDI, but instead increases up to 95.5% and remains stuck there. The actual and target air mass values show no suspicious discrepancies, both at idle and under full load.

The question is: Is the meaning of the MWB3/AGR rate reversed in the 2.5V6 compared to the 1.9? Or is there a defect present? Subjectively, the car drives well and reaches its top speed, but it feels slightly weak at low RPMs.

Hi.

Quote:

Is the meaning of the MWB3/AGR rate now reversed at 2.5V6 compared to 1.9?

Yes.

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Or is there a defect here?

No, it looks normal.

If there's a problem with the EGR valve, check the mass airflow readings.

Best regards, Rainer.

Thank you for the quick response! The world is now back to normal.