Technical X250, 2013 P0234 Overboost Pressure

[NavNie]

Hello everyone,

i am new here excuse my bad english, I use the help from a translation program.

A friend of mine has the following problem: he has a Ducato X250 2013, 150hp ECU Marelli 8F3, Motorhome with error

P0234 Overboost Pressure on rare occasions.

The MAP sensor and the vacuum valve have already been changed and work properly. During the analysis with AlfaObd the following status information:

Turbo valve condition with variable geometry: is not learned

Has anyone knowlegde about the AlfaObd function:

Turbo Actuator Pre-Align / Self Calibrate

If he starts the function, it will be rejected by the ECU with the message that the prerequisites are not met.

The following requirements have been prepared:
- Engine is idling
- Engine is at operating temperature
- Park brake applied
- No Gear
- No Breakpedal used

Hoping someone on the forum can help us.

Greetings Klaus

 

[kangexpress]

Has the turbocharger ever been replaced?

Milage / km?

 

[NavNie]

Hallo Kangexpress,

Your Questions:
Has the turbocharger ever been replaced? => No
Milage / km? => 65.000 Km

Greetings Klaus

 

[kangexpress]

Hallo Kangexpress,

Your Questions:
Has the turbocharger ever been replaced? => No
Milage / km? => 65.000 Km

Greetings Klaus

Maybe the VGT of Turbocharger is stuck in open position.

If you read the code with a diagnose tool you get further information by clicking on the code.
It's a freeze frame from of some parameters from the moment the failure did accure.
The freeze frame parameters can leed to the solution of the problem.

FIAT solution would be in many cases a new turbocharger.

I would recommend first to check vaccum pipes from vaccum valve to turbocharger.
You would need a vaccum pump and a diagnose tool which can show disred position and actual position of VGT Geometry, for that task.

First put vaccum on the pipe and look on the live data if the VGT is moving properly.
Second hold the vaccum for couple of minutes and look if the VGT is moving.
It shouldn't move and hold the pressure.
If it doesn't there is maybe a leak in vaccum pipes.
Second put pressure on the vaccum pipe.
It should also hold the pressure for couple of minutes.
If it doesn't than also vaccum pipe is leaking.

If VGT is moving freely and is holding pressure in both ways than we don't have a vaccum problem.

Next step would be to check wiring harness from Positionsensor to ECU.

 

[NavNie]

Hallo Kangexpress,

thank You very much, for all the necessary Test, you describe, we have done them all.

We already know that the Turbo mechanism is a little bit stiff. Our Problem is not the
thrown Error Message about the Overboost Pressure.

Our Problem is how to deal wit the Status Entry of the Marelli 8F3 ECU:

"Turbo valve condition with variable geometry: is not learned."


AlfaObd, instead of MultiEcuScan, Offers the Option: "Turbo Actuator Pre-Align / Self Calibrate"

But this Option doesnt Work, it will be rejected by the ECU with the message that the prerequisites are not met.
We are not able to run the Procedere.

We already know that some of then german FIAT Professional Workshops had Problems after Changing the Turbo, to get a stable System with no Boost Pressure Failures.

Maybe the "Turbo Actuator Pre-Align / Self Calibrate", could be a part of the "Reset to Zero, of the Self Learning Functions" which is Offert by AlfaObd and MultiEcuScan also.

We know to learn the Gearbox (autom / manuell), by pressing the Clutch Pedal, learning Cruise Control, the Steering Wheel Sensor...
But we dont know how to learn the "Turbo Actuator Pre-Align / Self Calibration"

So we hope to find someone whow is able to deal with: "Turbo valve condition with variable geometry: is not learned."


Greetings from Klaus