Technical Overboost followed by underboost

[Boardboi]

Hi all,have an ongoing problem with my 2013 fiat ducato 2.3 150 bhp engine fitted in my motorhome. I've recently bought a MES & managed to capture some data when I had a recent error code pop up. Can anybody shed any light on why this has happened from the attached image ?
Thanks

 

[Boardboi]

Just to add a bit more detail i got this second code 5 minutes later

 

[deejays]

Both over-boost and under-boost occurring. Could be caused by a number of issues. Could be wiring/connector issue on the MAP sensor - or (more likely?) a dirty or faulty MAP sensor. Could be an issue with the vacuum drive/vacuum driven boost solenoid that controls the turbo. Could be a faulty turbo. Could be a failing atmospheric pressure sensor in the ECU (highly unlikely). You might wish to perform some live data analysis using graphs in MES so you can examine graphical variations of the desired parameters as that may point you in the correct direction. Or you could start by replacing the MAP sensor and see if that fixes the issue.

 

[Boardboi]

Thanks for the reply.
Initially I found a hole in a intercooler hose & replaced it thinking I'd solved the issue......but the codes returned an hour in to the next drive.
I've now replaced the air filter,map sensor & boost control solenoid & oil change.....but the codes returned again also after an hour drive. Clearing the fault codes allows me to carry on driving & the van doesn't feel quite as responsive as it once did.
My next plan was a smoke test & vacuum test.

 

[deejays]

Your original screen grabs show the actual turbo control position not tracking the desired turbo control position, and they show the expected deviation that corresponds for the over and under boost conditions. This indicates the VGT vanes are not at the desired position being called for by the ECU. Were those screen grabs captured before or after you replaced the mentioned components? If after, then either the drive to the VGT or the VGT itself is not operating correctly (either a vacuum issue, or drive to the turbo control solenoid from the ECU, or a sticking turbo).

 

[Boardboi]

Those screen grabs were after I changed the components.
To my untrained eye I also noticed the air quantity was massively different.....and when air quantity was high the fuel delivered was also high compared to when the air quantity was low.
I'm also a bit curious why the fault appears at the hour mark.....maybe heat soak ?

 

[deejays]

Looking at the Parameters tab or freeze frame from the fault report, which is just a moment in time is nothing compared to looking at the same data in graphical form over a period of minutes on a drive. This is what you should be doing for any meaningful analysis. You could use a similar parameter list as per the link attached. It was originally designed for the dual EGR engine, but would be suitable for you - just ignore the LPEGR components. Your engine likely has a few other differences in parameters as well- number of lambda sensors would be one of them I think. https://fia.to/1dxzof

 

[Boardboi]

Thanks for that. It was the first time using MES so I'm still getting my head around using it. I will look at the graph option for better diagnosis.

 

[deejays]

Yes, it is a bit of a learning curve in itself. You will find it very powerful in what it can do for you. Have a good read of the manual and also check what is available on line videos etc. Live data analysis using graphs is gold.

 

[Boardboi]

There's a manual !?!
Not really a tech kinda guy but I appreciate how it's going to help in this situation.
I will keep playing with the 'new toy' & hopefully get to the bottom of this. Thanks again so far.

 

[deejays]

The manual can be found on the Multiecuscan site under the HELP Tab: https://www.multiecuscan.net/HowToUse.aspx
It is also in the Multiecuscan folder on your PC.