W166 error code P004671 turbo actuator sticking

[xlouis]

I identified the Y77/1 charge pressure positioner (boost pressure regulator/ turbo actuator).
I changed it with a new one, but the actuator still sticks, although I saw it working on the actuator test machine.
Is it possible with Xentry to control the actuator?
Could it be another element (i.e. the charge pressure sensor) that sends wrong signals to the actuator?

Thanks for your help.

Chris

 

[Mersovod]

Remove the control rod from the drive and check for ease of movement of the turbine blades. Sometimes the shoulder blades bend and they do not open completely. The new Y77/1 will not work. It also happens that the damper falls off the air intake and falls into the thrust of the drive rod.

 

[xlouis]

Thank you, Mersovod for your advice.
However, the correct mechanic working has always been checked.
You can read more in my presentation: https://autogmt.com/threads/place-for-your-first-post.109/page-41#post-4608
So I'm wondering if I wouldn't be able to control the actuator with Xentry.
Anyone who can give me more info?

 

[Mersovod]

There was something like that. The client had his turbine replaced under warranty with an OM642. After 1000 km, the emergency mode is again and the turbine does not blow. They changed it a second time at another service center and again the same problem. If the blades of the hot part of the turbine are damaged, the right exhaust manifold must also be replaced. The rotating ring of the blades also often jams due to the abundant presence of soot. Restored by cleaning.

 

[xlouis]

Here it is different: the turbocharger was checked, it was clean, the turbines are not damaged, the axle turns without play.
Incidentally, the car does not go into emergency mode.
The symptom is stuttering when I accelerate.
I think the problem is intermittent. So before I check all the wires and plugs, I would like to try to connect to the Y77/1 with a diagnosis program.
Can I do this with Xentry Passthru?

 

[Mersovod]

Yes, sure. You can run the Y77/1 check in Xentry.

 

[Mersovod]

The OM642 has a very clever system for monitoring pressure sensors. One will lie and the readings will be distorted to show that they are working properly. See the actual values of ALL pressure sensors at idle speed and with the engine turned off (IGN ON) The readings on the damped one should not differ by more than 30 mbar. The last case, due to the boost pressure sensor in front of the throttle, the driving dynamics periodically disappeared. At the same time, the revolutions increased normally, but there was no “pickup”.

 

[xlouis]

Hi Mersovod,
Do you mean that all sensors listed on the attached scheme have to been tested?
The boost pressure sensor in front of the throttle is the B5/1, right?
What do you mean with "there was no pickup"?

 

[Mersovod]

Hello. I mean dynamic overclocking.