AGR Tax Parameters for ATJ Engines

Hi,

After cleaning the EGR valve restored the poor performance of my ATJ engine, I'm interested in knowing which operating parameters influence the EGR valve's operation. Since the EGR function on this engine isn't feedback-controlled, its operation must depend on other parameters.
It has already been mentioned here that the EGR valve is closed in the upper load range and under full load. I have the feeling that the engine speed and coolant temperature also have an influence. (Subjectively, I experienced this feeling by comparing with and without the EGR valve). Since I don't have the ability to log data, I can't compare the actual values and try to draw conclusions from them. Perhaps someone here knows more.

Greetings.
ejmk

ejmk wrote:

I am interested in understanding which operating parameters influence the activation of the AGR (Abgasrückführung). Since the function of the AGR is not feedback-controlled in this machine, its activation must depend on other parameters.

Hi.

Take a look at the technical article on LMM (likely referring to a specific technology or product), it should be in there - at least for the common 1.9 models.

What kind of machine is the ATJ?

ulf wrote:

Hi Take a look at the LMM technical article; it's in there - at least for the common 1.9 models.

You're welcome, I completely missed that.

But since we're already here, let's make another request.
In the aforementioned technical article, it states that the mass of air drawn in serves as a negative feedback mechanism for the EGR (Exhaust Gas Recirculation) control. This would imply that a faulty mass airflow sensor (MAF) would reduce the control setting for the EGR. This, in turn, would potentially lead to improved load behavior in the partial load range. Or am I misunderstanding something?

ulf wrote:

What kind of machine is the ATJ?

1.9 TDI
85 kW
Installed in a Passat manufactured in 04/00.

ejmk wrote:

In the aforementioned technical article, it states that the mass of air drawn in serves as a negative feedback mechanism for the EGR control. This would mean that a defective mass airflow sensor (MAF) would reduce the control variable for the EGR. This, in turn, would lead to better load behavior in the partial load range. Or am I mistaken?

No, that's right.
This is also described in the technical article under the section on LMM defects .