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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

@theoneandonly I managed to setup MES and hopefully loaded your T5. I took our vehicle for drive and within 10 minutes I received the 401 and 238 errors. File 1 is the data collection prior to and including the error. File 2 is further 20 minutes driving and during this period (and as is the norm) no further errors occurred. I have also added the info page and screen shots of the error codes. With regards to soot in the exhaust that was also checked and we do have soot at the end of the exhaust. Please let me know if I have missed anything
 

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  • 401a.jpg
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  • Info - 08102023.jpg
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  • FESExp_2310081138_Fiat Ducato (type 290) 2_3 Multijet_File1.csv
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  • FESExp_2310081204_Fiat Ducato (type 290) 2_3 Multijet_File2.csv
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Fredastaire said:
Van is 2017 Euro 6 bought new , now with 26K on clock.

Problems started this summer with dash engine light and code P0401 appeared on a country lane at low speed going into a corner so it would be low airflow going in to the engine as it wasn’t ‘working’. Bought FCR and cleared fault, happened again days later, including P0402, cleared it.

So its an intermittent fault., it might be days before it happens again. Dealer had a look, diagnosed software needed latest issue which he installed.

Still getting P0401

Then going up a hill with foot down a bit I get a double whammy of P0401 and P0236 plus P0238 and the dreaded limp mode.

After much reading on here I decided to but MES software for laptop and checked things, both EGR’s cycle fine, DPF is cycling fine and not blocked so scratching head and thinking, more reading on here and I decided to change the top high temp EGR thinking it was sticking. Brand new Fiat part from Coastal Motorhomes fitted and codes cleared, still intermittent getting P0238 P0236 and Limp Mode.

More reading on here led me to check the fine bore plastic vacuum / pressure pipes, all fine, more reading so took the left hand intercooler pipe assembly off suspecting cracked bracket, perfect, looked inside cooler, not blocked, visually checked the RH intercooler pipe – fine, checked intercooler – fine.

Ive ordered new Fiat MAP and turbo vacuum solenoid, yet to arrive.

I would appreciate comments and advice as to what I do next, Ive been told @whineO or @Euroserve might be able to advise, is it possible?
Click to expand...
You haven't got a bad driver's wing mirror by any chance as the sensor in there causes all sorts of issues like this
 
@Sfrain145y first question is do you own a twin EGR non Adblue Ducato?
We have already learnt that the DPF is susceptible to cracks from heat damage, this is seen as soot in the exhaust pipe of the silencer.
Exactly what causes the heat damage is our biggest unknown, certainly Fiat know and have installed revised software in many owners vans at a service.
It's this soot that then passes through the LP EGR system and clogs the cooler to the extent of the engine being unable to breath.
As of yet none of us has identified an outside temperature problem as faulty with a twin EGR variant, that said we are aware of other owners of Boxers and Relays having allied problems and it on my list to buy a spare probe of eBay for my rainy day stock.
Further comments welcome.
 
Fredastaire said:
Further comments welcome.
Click to expand...
Regards @BoultsG problem. Having looked at his results would you consider the DPF Differential Pressure low? My thinking is the a low pressure due a faulty transducer or blocked pipe to the transducer could stop a regeneration taking place. If the DPF contains soot above where a regeneration should have taken place could the excess soot be pushed into the EGR Cooler blocking it?
 
CheeseMonster said:
Regards @BoultsG problem. Having looked at his results would you consider the DPF Differential Pressure low? My thinking is the a low pressure due a faulty transducer or blocked pipe to the transducer could stop a regeneration taking place. If the DPF contains soot above where a regeneration should have taken place could the excess soot be pushed into the EGR Cooler blocking it?
Click to expand...
I ve only had a quick look at @BoultsG results (been a buzy sunday for a change) , the lpegr temperature results are low but only just got to temperzture so my thought are a longer run is required before conclusions.

dpf sensor results are spot on, if higher than 150-250 we are in the realms of a blocked dpf and can see lpegr getting blocked with low temperatures. The valve is moving from max to min with no control values. I am reluctant to draw conclusions without a longer run as the engine is only just upto temperature.
A 10 to 15 min blast at 60mph down motorway would be perfect.
 
theoneandonly said:
dpf sensor results are spot on, if higher than 150-250 we are in the realms of a blocked dpf and can see lpegr getting blocked with low temperatures. The valve is moving from max to min with no control values. I am reluctant to draw conclusions without a longer run as the engine is only just upto temperature.
A 10 to 15 min blast at 60mph down motorway would be perfect.
Click to expand...

I agree with you to a point, if the pressure was over 150-250 the DPF would deemed blocked, but this is assuming the Differential Pressure Sensor is reading correctly.

So my questions are:
Q1: Shouldn't a high DPF pressure generate a regeneration?
Q2: An under-pressure measurement (from a faulty pressure sensor) would fail to start a regeneration even if the DPF was full?

I haven't yet been able to work out what values both MES and Alfaobd send and how they get % DPF is full. Not enough time time yet.
 
CheeseMonster said:
Q1: Shouldn't a high DPF pressure generate a regeneration?
Q2: An under-pressure measurement (from a faulty pressure sensor) would fail to start a regeneration even if the DPF was full?

I haven't yet been able to work out what values both MES and Alfaobd send and how they get % DPF is full. Not enough time time t.
Click to expand...
Q1 if pressure too high, regens are prevented tt
Q1 should be what presure or conditions are regens initiated
Q2 a dead sensor will stop regen

A differential pressure sensor with condensation on either side will stop regen. The x250 had the dpf and sensor low down and was prone to sensor problems (i know of someone had 3 problems) the x290 has the sensor high up on the firewall above the DPF, condensation less likely to stay in sensor. (I still got a spare in glovebox).
I dont know what % is regarded as full.
What i do now is monitor how regen occurs. Indicated by post injection value, as regen progresses you can see the dpf sensor value and % blockage go down. its all in template 4 of my new ini file. This will eventualy give a range of blockages observed, or when regen occurs.
 
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@BoultsG ive re-read you initial post and @13.2 mins long your run should be long enough. I looked at the sample rate on my results 2.2 seconds whereas yours is 7 seconds so can be missing data that fills in the gaps ie only max to min for lpegr position. This is some thing i could have missed on another set of results. Currently i am unable to explain the difference in sample rates (simular number of samples). Anybody any clues?
 
theoneandonly said:
@BoultsG ive re-read you initial post and @13.2 mins long your run should be long enough. I looked at the sample rate on my results 2.2 seconds whereas yours is 7 seconds so can be missing data that fills in the gaps ie only max to min for lpegr position. This is some thing i could have missed on another set of results. Currently i am unable to explain the difference in sample rates (simular number of samples). Anybody any clues?
Click to expand...
Is it linked to the Sample rate on the graph page?
F5 > R
 
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An interesting morning, I started the engine and left it to idle whilst I was sorting a few things out, so idling for around 5-10 minutes. I then took a drive down the motorway as suggested by @theoneandonly. We are only a couple of miles away from the M40 so easy to take drive. This was the first time that I have not received the P0238 error and put in to limp mode. However when I completed the journey and exported the data I checked the error codes and found that at some point during the drive I received a P0401 error. Hope this all helps.
 

Attachments

  • 401-61.jpg
    401-61.jpg
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  • FESExp_2310091205_Fiat Ducato (type 290) 2_3 Multijet_File1.csv
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theoneandonly said:
No. Thanks for looking.
Its mentioned in the manual.
I've thrown an email to grant at gendan, see what happens
Click to expand...
I did see in the manual it talks about Priority but I couldn't see where to adjust that. It also mentions about the more points you record the slower it gets, obvious but not very helpful.
 
@theoneandonly look at the ECU stupid request for air, a crazy impossible unachievable figure. I recommend it's time for a serious look at the LP EGR openings and temperatures. It's behaving just like mine before I changed the cooler.
 
Fredastaire said:
@theoneandonly look at the ECU stupid request for air, a crazy impossible unachievable figure. I recommend it's time for a serious look at the LP EGR openings and temperatures. It's behaving just like mine before I changed the cooler.
Click to expand...
Strangely enough thats what ive been doing but the 7second delay is giving results that is odd
eg 1st graph boost desired versus actual gives results that dont follow each other but the difference shows results out of step (in my mind). I just add all graphs The lpegr openings are max to min but in a time frame that mine has 3.5 readings ie we could be missing all the inbetween ones, I am in conversation with Gendan to get thier take. The latest temperatures are supurb max 144 mean 100. so i am reluctant to definitly suggest any thing other than retest with only 4-5 pids at a time to eliminate the sample rate issue.
I will advise on this later.
Engine BG turbo.jpg

Engine BGAir input.jpg

Note the actual to desired is 25% same as many previous examples of a P0401

Engine BG DPF.jpg

Differential pressures good no obvious problems
Engine BG injector variation 9-10-23.jpg


Engine BG LPEGR.jpg

No middle openning only min to max, Vgood temperatures
 
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BoultsG said:
An interesting morning, I started the engine and left it to idle whilst I was sorting a few things out, so idling for around 5-10 minutes. I then took a drive down the motorway as suggested by @theoneandonly. We are only a couple of miles away from the M40 so easy to take drive. This was the first time that I have not received the P0238 error and put in to limp mode. However when I completed the journey and exported the data I checked the error codes and found that at some point during the drive I received a P0401 error. Hope this all helps.
Click to expand...
what inter face are you using USB or Bluetooth
 
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