Technical Fiat suggesting new DPF because P401 - why?

[sockettrousers]

Sorry to ask _another_ P401 question... Since early Feb, our 2019 Dual EGR Ducato has been showing intermittent P401/402 faults.

We have had the low pressure EGR replaced by a a local garage and Fiat have updated the ECU software. Neither of these fixed the problem. The latest error codes are:

P040161 Air control negative governor deviation low air quantity - Signal calculation failure
P040261 Air tracking control system - Signal calculation failure

Fiat's latest suggestion is to replace the injectors, the DPF and EGR (again but lets not think about that).

This is costing £6000 in parts and Fiat are paying half of that. Annoyingly, yesterday, the wrong DPF arrived from Italy and the right part is now showing out of stock on their system.

The dealer's technician says that the van is drivable but with the engine light on the DPF will not regenerate and we risk it getting blocked and then refusing to start. The DPF is currently showing 25% full - which seems like it has regenerated in the last few hundred miles.

So, after reading most of the threads on this forum and understanding some portion of them, I'm trying to understand why Fiat are suggesting a new DPF and what risk we face if we get the new injectors fitted and drive on the old DPF.

 

[theoneandonly]

Ducato twin EGR Engine with P0401 Code (2016 to 2019)

This does not refer to earlier single EGR systems or to later AdBlu SCR engines. Note this is a guide and not definative. It is up to you to make decissions. It is the result of my investigations of data from many contributors and discussion with...

www.fiatforum.com

Read this and wipe the exhaust with kitchen roll. Have they updated your ecu software, do you know the version? Are there any other codes.
Once youve read and can answer questions come back and i will try to answer any questions.
The most important next step is gathering live data with software on a laptop. Multiecuscan. From this we can tell if you are in the early stages of the lpegr cooler syndrome or well established. You are currently missing one of the tell tale signs but data will confirm.

What software/ hardware do i need to read OBD2 Codes

This a much bigger question than first appears. If we limit it to what is a cost effective DIY solution to "read my Fiat and simple maintenance issues eg change the oil in my euro 6 or add a new MAF sensor" then the answer for me reduces to...

www.fiatforum.com

 

[theoneandonly]

Have Fiat dismantled the dpf / exhaust joint and found soot? Have they given a reason for changing dpf? Like its cracked and exhaust gas is now cloging up the cooler. The cooler will need changing or cleaning if diagnosis is confirmed. It is possible to run new injectors without a new dpf reccomended? questionable? @Fredastaire

 

[sockettrousers]

Have Fiat dismantled the dpf / exhaust joint and found soot? Have they given a reason for changing dpf? Like its cracked and exhaust gas is now cloging up the cooler. The cooler will need changing or cleaning if diagnosis is confirmed. It is possible to run new injectors without a new dpf reccomended? questionable? @Fredastaire

Hi. No. After some discussion, they are telling me the injectors are to blame and the DPF replacement is because the design changed and so they must upgrade all three ( injectors/DPF/DFU) at the same time .

SW was updated about a month ago, not sure before that. I don't have the version handy but I'll ask.

Will wipe the exhaust this afternoon when I pick it up

I don't have access to a windows laptop to run multiecuscan but I'll try and get a trace with my cheapo ODB and the iOS version.

 

[Fredastaire]

@sockettrousers by now you should have read through the main forum post (44 ish pages long) which I originated. I work on here together with @theoneandonly to help other sufferers on here.
I am flabbergasted that there is no mention so far about your LP EGR cooler.
It's an absolute must that you get hold of a windows laptop and buy the Multiecuscan software plus lead, then go for a drive collecting data to email to @theoneandonly.
.
Together we know how to look at the data and see if your injectors are really knac...ed, how to know if the cooler is blocked and to know if the DPF is wrecked. I still cannot understand why garages get it so wrong when on this Forum all the help and knowledge is here.
.
It's going to cost you £100 plus using a laptop to know exactly where you stand and what you need.
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I'm the owner of the Ducato on the 44 page post, I had a new cooler fitted two years back and I'm still driving it, yes I know my DPF is cracked, yes I'm wondering how long before the cooler needs changing again.
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Do please please buy Multiecuscan and let us help you make the right forward decisions.

 

[Ocwobio]

Hi. No. After some discussion, they are telling me the injectors are to blame and the DPF replacement is because the design changed and so they must upgrade all three ( injectors/DPF/DFU) at the same time .

SW was updated about a month ago, not sure before that. I don't have the version handy but I'll ask.

Will wipe the exhaust this afternoon when I pick it up

I don't have access to a windows laptop to run multiecuscan but I'll try and get a trace with my cheapo ODB and the iOS version.

I would add, do not cheap out on the OBD lead, and avoid wireless solutions. Much info, advice, and tales of woe on here from those who did. However, a cheap laptop with windows 7 or 10 should suffice, and IDK but the trial version of MES may record enough data?

 

[Fredastaire]

For anyone reading this post please can I recommend you read and join us on the main detailed post /www.fiatforum.com/threads/ducato-p0401-p0402-p0236-p0238-and-limp-mode-its-2017-euro-6-egr-changed-what-do-i-check-next.491167/ I started this post some years back and are surviving the problem.
.
I also strongly recommend that you buy Multiecuscan with its leads and its license from Gendan UK, it will allow you to immediately start investigations and not fall in to the big hole often found with budget leads when they fail to work or dont pass the total level of data needed per datarun.
.

 

[Ocwobio]

For anyone reading this post please can I recommend you read and join us on the main detailed post /www.fiatforum.com/threads/ducato-p0401-p0402-p0236-p0238-and-limp-mode-its-2017-euro-6-egr-changed-what-do-i-check-next.491167/ I started this post some years back and are surviving the problem.
.
I also strongly recommend that you buy Multiecuscan with its leads and its license from Gendan UK, it will allow you to immediately start investigations and not fall in to the big hole often found with budget leads when they fail to work or dont pass the total level of data needed per datarun.
.

Another vote from me for Gendan!

 

[varesecrazy]

If you need some convincing of the MES software

There Is a long list of forum members who have the software.. Look around on the forum

Ask about a visit/demo of their kit, should help explain what your basic OBD will fall down with

 

[theoneandonly]

An extract from the mes register of people willing to help. This in tonbridge.
May not want to do a 30 minute run required to collect necessary data . As @varesecrazy says
But enough to show how useful it is

West Kent

I'm an independent FIAT mechanic in Tonbridge - happy to give a free MES diagnostic plug-in (and operations like proxi alignment) to anyone at TN9 2UH if you get in touch and give a bit of notice. Or for GBP30 on a come-to-you basis within 15...

www.fiatforum.com

 

[sockettrousers]

Quick update on this: I'm completely up for getting multiecuscan working and I am reading the main thread and chatting to @theoneandonly directly - but my main challenge right now is that I don't have a PC so I'm trying to get it working on my Mac under Wine/Crosssover. It's a faff but I want to monitor this and I'de prefer not to buy and then carry a PC in my PVC just for this.

Current state of that is that it kind works but crashes very quickly after connecting with a USB ODB. Multiecuscan does connect to my WiFI ODB (and doesn't crash) but MES doesn't't like that ODB :-(

I'll see if Gendan UK can help with a WiFi adapter.

I have asked the one other person on the MES forums who claims to have MES under Wine working and, the one person on the Crossover forums.

 

[Twotone2]

I have the trial version of MES working on a M1 MBA via parallels and WIN 11 but I decided to buy a cheap windows 10 laptop and use MES that way the laptop cost me £85 delivered MES works perfectly that way, I gave up on the Apple way as it’s too much of a faff ie no usb port in the MBA and having to buy a yearly subscription for MES plus there’s much more support for MES using a proper windows laptop and a usb connection to the car.

I bought the canbus version which comes with the two connectors and a licence for MES, total cost, including the laptop was £200.