Technical Ducato P0401 P0402 P0236 P0238 and limp mode its 2017 Euro 6, EGR changed, What do I check next

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Technical Ducato P0401 P0402 P0236 P0238 and limp mode its 2017 Euro 6, EGR changed, What do I check next

Try again in 4th / 5th gear.

Going from 2000 to 2500 RPM.
With 40-50% race pedal.

Try to hold desiered boost pressure at 2000 mbar for some time.
So that we can see if there is a difference in desired boost pressure and actual boost pressure.
 
Also clean the air intake system.

- clean boost pressure sensor (MAP) (under the throttle on front side of the engine)

- clean HPEGR Valve and pipes (pipe from HPEGR to intake gets clogged fast)

- clean MAF

- change air filter
 
My experiance is that the Intercooler and LPEGR Cooler are the main obstruction points (most soot is in those two components). It is very easy job to take intercooler out of the van.....
 
Hi all.
Unfortunately I am part of your club too. I have a Ducato 2.3, 2017 Euro 6, F1AGL411D. It has 60K on the speedo, and is running v23 software.
I have battled intermittent P0401, 402, 236, and 238 faults for around 2 years now, from 50k on the speedo.

What I can bring to the forum is a reproducible MIL condition. I get the MIL only in the first 10 minutes of driving. Only at low load, and generally at 80km/h coming off the throttle. I then reset the code, drive it hard for 10 minutes, and the rest of the journey is fine. I can reproduce the fault condition 5 minutes after leaving the house, around 70% of the time.

I have replaced MAP sensor, turbo solenoid, turbo solenoid pipes, and apparently wasted $600 NZD on the HPEGR replacement.

My truck air circulation system is sooted up - see attached photo of HPEGR prior to cleaning / replacement.

I have MES, and note that the fault occurs when the actual turbo pressure is much lower than the desired. This happens when only the LPEGR is supposed to be open. I do not get a large difference between turbo desired and actual pressures if the HPEGR opens to assist the LPEGR, or just the HPEGR is open (where desired and actual track perfectly).

The next thing I was going to change was the Bosch 0281006287 Exhaust Pressure Sensor, although I might hold out to see where we settle with this forum. I'm happy to buy one of these sensors though and change it as part of the knowledge pool, it can just take a month for parts to get down to New Zealand in this post(?)-pandemic world.

Advice is welcome. Truck MIL is currently manageable, and happy to contribute with testing. If there are any specific tests you would like me to perform and track on MES, I can. Its easy to spot when the MIL comes on, as turbo actual pressure immediately drops to atmospheric, and stays there.
 

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Hi all.
Unfortunately I am part of your club too. I have a Ducato 2.3, 2017 Euro 6, F1AGL411D. It has 60K on the speedo, and is running v23 software.
I have battled intermittent P0401, 402, 236, and 238 faults for around 2 years now, from 50k on the speedo.

What I can bring to the forum is a reproducible MIL condition. I get the MIL only in the first 10 minutes of driving. Only at low load, and generally at 80km/h coming off the throttle. I then reset the code, drive it hard for 10 minutes, and the rest of the journey is fine. I can reproduce the fault condition 5 minutes after leaving the house, around 70% of the time.

I have replaced MAP sensor, turbo solenoid, turbo solenoid pipes, and apparently wasted $600 NZD on the HPEGR replacement.

My truck air circulation system is sooted up - see attached photo of HPEGR prior to cleaning / replacement.

I have MES, and note that the fault occurs when the actual turbo pressure is much lower than the desired. This happens when only the LPEGR is supposed to be open. I do not get a large difference between turbo desired and actual pressures if the HPEGR opens to assist the LPEGR, or just the HPEGR is open (where desired and actual track perfectly).

The next thing I was going to change was the Bosch 0281006287 Exhaust Pressure Sensor, although I might hold out to see where we settle with this forum. I'm happy to buy one of these sensors though and change it as part of the knowledge pool, it can just take a month for parts to get down to New Zealand in this post(?)-pandemic world.

Advice is welcome. Truck MIL is currently manageable, and happy to contribute with testing. If there are any specific tests you would like me to perform and track on MES, I can. Its easy to spot when the MIL comes on, as turbo actual pressure immediately drops to atmospheric, and stays there.
Do you have any soot in the exhaust pipe?
Is the exhaust pipe black from inside or clean?
You can test it with a clean white tissue.
If it gets black than there is a problem with the fuel / air ratio or a broken dpf.
Either to much fuel (check injector values) or to less air.
Or blocked / broken dpf (check dpf values, differential pressure, avg. regeneration temp., avg. regeneration km,...)

If the exhaust pipe is clean,
the diffential pressure in idling between 0-15 mbar or under full load 80-125 mbar,
the injector correction values add up to zero and are max. +/-2,
the avg. temp of regeneration over 600C,
the avg. reg. km over 500km.

Than there should be no issues with these components.

You are saying that you get the code in the frist 10 minutes.
Can you check next time before starting the car if the code is already stored.
I've noticed in my case that code was stored in ECU but MIL was still off.

You can get rid of the codes by replacing or cleaning the LPEGR Cooler.
But that's an 6-8 hours job.
And if there is any issue with fuel or air or dpf, the LPEGR Cooler will get sooted again.
You should also update to v32.

Other solution is to delete egr system from ecu.
Therefor you will need someone who can program marelli 9DF ecus.
 
I agree with the above and can add only a little.
Mine sets 401 at slowing down, foot off accelerator. It sets as pending code first, (no Mil), then you can drive all day. If the pending code is not cleared the next day, if the same conditions occur the pending 401 + another 401= set MIL light.
If you drive with MES running watch the LP EGR temperature, with the LPEGR open the temperature should be +- a little around 100 and say 60ish closed. If you don't see any change then the cooler is totally blocked, if say it slowly increases from 60 to 70/80 then it's partial blocked.
.
Removing the cooler to change or clean as said is a long job as you need the subframe removing. I still wonder if there is a way of unbolting the engine mounts and moving the engine forward to enable removing the DPF.. I'm also wondering if it's possible to undo the flexi pipe to the cooler and spray EGR cleaner up with engine running. (Blanking the exhaust outlet first).
I'm planning to have my van up on ramps this week to go under and have a detail look.
 
Hi. I posted a query yesterday in the General section about apparent EGR issues and have been referred here. Scary reading! Basically I have a 2018 2.3 facelift with Comfortmatic on a campervan body. It seems to be a twin EGR (no Adblue) model and 9 months ago at around 12,000 miles threw its first wobbly with limp mode and check engine light. Roadside callout said sticky EGR and sent me on my way. Second similar limp mode experience recently at 15,000 miles so I now need to get it sorted. Being a campervan it only gets taken out occasionally and I let the comfortmatic do its thing with gentle revs - this may be part of the problem. I'm way out of my depth compared to what some of you have done diagnostically but still need to gather some data such as the precise fault code. The prospect of further limp mode instances, possibly occuring on a mid-lane heavily congested motorway and subsequent multi-hour wait at the side of a road with or without hard shoulder is not attractive so I've contacted Gendan for advice about a suitable OBD reader so at least I can get some basic data and more particularly, self-rescue as simple fault clearing has got me home. Any further advice about a suitable hand-held OBD that can be kept in the glove box for that purpose would be very helpful and welcome. I'm not confident about my ability to get to grips with a software package like MultiEcuscan and in any case don't have a suitable laptop. Neither do I have the mechanical skills to repair/replace parts so ultimately may have to pass to dealer - but with some self-diagnosis as, if I can at least mitigate the likely high cost by preventing unnecessary HPEGR (for example) - so much the better. At the moment I seem to align most closely with the experience of fredastaire who like many of you on this thread have all done incredibly well to get where you are on this problem. As set out in my General section post I've wiped clean my exhaust pipe and plan to shortly do a 30 min hard run with the gearbox in manual mode to see what visible exhaust output I currently have. Van otherwise seems to run well, passed emissions test on recent MOT after first limp mode instance, mid-thirties mpg and no visibly excessive black smoke and now about 3,000 miles covered since first limp mode occurrence.​
 
@zakandme , lets get you started.
If you get Limp Mode, you pull over, stop engine, wait a few seconds and restart. 99.9% it will clear the limp mode.
Second buy a low cost fault code reader from the likes of Argos, cost say £20-30 ish, it will get you started in reading codes and being able to clear them. This low cost start means you dont need to compare or think - just buy it and get on with being able to clear codes and drive on without roadside assist from whoever. Later you can buy something more advanced.
By the way where are you? perhaps add you village or town so we know where you are without giving away on the internet your exact location. Maybe one of us is near you perhaps.
Ill stop here and begin again on the next post.
 
@zakandme now perhaps you are not so frightened about being stuck at the side of a motorway for hours.
You now need to do a full read up on this entire post (I started it) and probably get a friend who has mechanical knowledge to help you understand.
The origins were when the EU brought in stiffer emmission regulations, whilst most manufacturers went to ablue, some others went for a Twin EGR system. Fiat got something wrong with the software which causes the injectors to overfuel at times, the extra soot can block and sometimes ruin the DPF, when it makes it through it then settles on the filter gauze of the LP EGR cooler, once part blocked the engine cannot get enough air, its part strangled so it throws the fault codes(s).
Fiat have developed the software a few times, the latest is version 32 for the engine and an update for Comfortmatic, they also did an internal technical document which some of us have a copy of, they seem to have done a recall probably in some countries, we in the UK didnt get it.
I strongly advise you find somebody with a laptop and that you buy Multiecuscan MES so with help you can interrogate your engine and see where you stand.
Next my advice is to change your fuel to the expensive grade diesel and add something like Millers ecomax (for diesel) so you can give the engine a chance to clean the injectors, now take it for a half hour run at in a lower gear consistant at say 60mph on a dual carriageway / motorway to give the engine a chance to get properley hot and burn itself cleanest.
Now you need that laptop plus friend and MES to interrogate.
Dont at this stage go to any dealer, they will read the fault codes, which will incorrectly say that its the HP EGR thats blocked and they will charge you £600 to replace. The 401 code is totally missleading, its causing owners worldwide to buy an unnecessary EGR. Its actually the LP system which is blocked, not the HP.
got to go just now, ill come back later...
 
Do you have any soot in the exhaust pipe?
Is the exhaust pipe black from inside or clean?
You can test it with a clean white tissue.
If it gets black than there is a problem with the fuel / air ratio or a broken dpf.
Either to much fuel (check injector values) or to less air.
Or blocked / broken dpf (check dpf values, differential pressure, avg. regeneration temp., avg. regeneration km,...)

If the exhaust pipe is clean,
the diffential pressure in idling between 0-15 mbar or under full load 80-125 mbar,
the injector correction values add up to zero and are max. +/-2,
the avg. temp of regeneration over 600C,
the avg. reg. km over 500km.

Than there should be no issues with these components.

You are saying that you get the code in the frist 10 minutes.
Can you check next time before starting the car if the code is already stored.
I've noticed in my case that code was stored in ECU but MIL was still off.

You can get rid of the codes by replacing or cleaning the LPEGR Cooler.
But that's an 6-8 hours job.
And if there is any issue with fuel or air or dpf, the LPEGR Cooler will get sooted again.
You should also update to v32.

Other solution is to delete egr system from ecu.
Therefor you will need someone who can program marelli 9DF ecus.
Exhaust pipe is black and sooty. The same black soot that was all through my HPEGR, was in the throttle body, and is no doubt all through the intake manifold.

Differential pressure at idle is 5mbar. Under full load is 100mbar.
injector correction values are maximum +/- 1 at idle, and near zero under load. They always add to zero.
Average regen temperature is 655C.
Average regen distance 2428km.
I generally have no codes on startup. Occasionally I do have a 401 that doesn't show up as a MIL.

I have access to an experienced Ducato coder, who liaises with other Ducato coders across the world, and can remap the engine.

It seems to me that coding out the LPEGR will stop the soot getting through the engine and all the sensors, but the DPF may still be broken.
Any advice on what to do based on the above information?
Is a DPF replacement and a LPEGR cooler clean the logical step, or do I just see about getting the LPEGR coded out?
 
@zakandme now perhaps you are not so frightened about being stuck at the side of a motorway for hours.
You now need to do a full read up on this entire post (I started it) and probably get a friend who has mechanical knowledge to help you understand.
The origins were when the EU brought in stiffer emmission regulations, whilst most manufacturers went to ablue, some others went for a Twin EGR system. Fiat got something wrong with the software which causes the injectors to overfuel at times, the extra soot can block and sometimes ruin the DPF, when it makes it through it then settles on the filter gauze of the LP EGR cooler, once part blocked the engine cannot get enough air, its part strangled so it throws the fault codes(s).
Fiat have developed the software a few times, the latest is version 32 for the engine and an update for Comfortmatic, they also did an internal technical document which some of us have a copy of, they seem to have done a recall probably in some countries, we in the UK didnt get it.
I strongly advise you find somebody with a laptop and that you buy Multiecuscan MES so with help you can interrogate your engine and see where you stand.
Next my advice is to change your fuel to the expensive grade diesel and add something like Millers ecomax (for diesel) so you can give the engine a chance to clean the injectors, now take it for a half hour run at in a lower gear consistant at say 60mph on a dual carriageway / motorway to give the engine a chance to get properley hot and burn itself cleanest.
Now you need that laptop plus friend and MES to interrogate.
Dont at this stage go to any dealer, they will read the fault codes, which will incorrectly say that its the HP EGR thats blocked and they will charge you £600 to replace. The 401 code is totally missleading, its causing owners worldwide to buy an unnecessary EGR. Its actually the LP system which is blocked, not the HP.
got to go just now, ill come back later...
Wow! Thanks fredastaire for the prompt and helpful reply. I'll do as you suggest and run through some Millers Ecomax Diesel at the next opportunity. I've been put off buying a code reader at that price point because of reviews saying they wont read later Ducato codes - hence my email to Gendan for something compatible but am happy to go with anything you can recommend or see what they come up with. I'll also resign myself to reluctantly migrating my new windows 10 laptop from home to the van and following the Multiscan MES tutorials! Do I need a particular module from Gendan to plug into the van socket?
Although the van is stored at a friend's address, I have relatively easy access but no facilities but at a pinch I could keep it short term at my own address. I have a Lake District trip planned with the van for next month and am determined not to miss it if at all possible. Whole business leaves me thoroughly disillusioned and I'm aware things may well get worse!
 
@Bigruss it would be useful if you were to run the following tests, preferably from cold then for 10mins after warm up. And post the csv file here or pm me. Further instructions if required are in a tutorial see guides at top of page.
View attachment 407544
I thought I was going to be out of luck tonight, with no fault codes to deliver.
Then at second 806.14, I got a triple whammy - 236, 238, 401.
Nearly the full set we're lookin at in this thread!
Its always easy to spot the when the MIL activates, as actual turbo pressure drops to atmospheric pressure - about 990mbar - ie. the ECU shuts the turbo off.
I haven't conducted any further analysis of the csv yet - over to the group to see what they think.
 

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@Bigruss if you read back very early on I’ve said that there are at least two fault scenarios. I also had the double whammy. The turbo solenoid is known to fail on mileage ie worn out, mine was at 24k miles I think. It’s reported on other posts on here. One member on here ran his 2017 Ducato trade vehicle to 280 thousand miles changing the solenoid every 24k miles!. The other known believed fault is the MAP sensor where the factory fitted MAP is not the correct Bosch number. Both items are low cost, say £90 the pair and relative easy to change if you have nimble fingers and a mirror to spot some of the fixings. This left me with just the 401 appearing intermittently.
 
@zakandme further to your reply, I most strongly recommend that you go for the expensive diesel from one of the big name suppliers, don't think of supermarket diesel. Our friends son works on diesel engine development for a major UK engine manufacturer, he states that supermarket diesel is basic and contains little or none of the 'cleaning' and 'best burn' additives which you get with major brands. He's one of the worlds top working engineers involved in emissions achievement to reach world governments regulations so I believe what he says.
With Comfortmatic I now very quickly select the 'uphill mode' to make the engine revolutions higher to keep airflow higher when driving in rolling countryside plus putting foot down when going uphill to make the engine work.
 
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