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

[kangexpress]

This, courtesy of @Fredastaire from Page 16 of this long saga: View attachment 449843

I guess caustic soda is very aggressive and will destroy the metal.

 

[theoneandonly]

@chumleywarner one thing you can check is the exhaust pipe. wipe with a kitchen roll. is it clean, sooty or oily.
read this, a more condenced version.

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

 

[theoneandonly]

I guess caustic soda is very aggressive and will destroy the metal.

It destroys Aluminium but ok with stainless steel of the egrcooler.
as to cleaner , take a look at this Jimmy makes his living from cleaning DPFs and associated problems. the Launch fluid is now his favourite.

youtube launch dpf clean at DuckDuckGo

DuckDuckGo. Privacy, Simplified.

duckduckgo.com

 

[Fredastaire]

Ref Caustic cleaning.
.
I've cleaned both my HP EGR and my LP cooler, the cleaning is very quick, not seen any metal damage. It takes only minutes of time.
.
I restore Corgi toys and Dinky toys. No metal damage on the bodies HOWEVER I did leave some Corgi wheels in overnight, couldn't find any trace the following day!!!!!!!

 

[deejays]

Ref Caustic cleaning.
.
I've cleaned both my HP EGR and my LP cooler, the cleaning is very quick, not seen any metal damage. It takes only minutes of time.
.
I restore Corgi toys and Dinky toys. No metal damage on the bodies HOWEVER I did leave some Corgi wheels in overnight, couldn't find any trace the following day!!!!!!!

So, I am wondering if anyone is going to try unblocking a blocked/near blocked LP EGR cooler in situ using the method described on the previous page, using a solution of caustic soda as described by @Fredastaire? What concentration should be used, and how long to leave it before flushing with water and then drying with compressed air? @kangexpress Is it worth giving it a try on the unit you have - it may save a lot of time and expense?

 

[kangexpress]

So, I am wondering if anyone is going to try unblocking a blocked/near blocked LP EGR cooler in situ using the method described on the previous page, using a solution of caustic soda as described by @Fredastaire? What concentration should be used, and how long to leave it before flushing with water and then drying with compressed air? @kangexpress Is it worth giving it a try on the unit you have - it may save a lot of time and expense?

For that one I've already ordered a new cooler.

Next one will be worth a try.

 

[JDA]

Hi all, (first post so not necessarily where it should be posted-apologies if not)

first of all a quick qualification of me and my situation, we have a Ducato based motorhome with comfortmatic (130 multijet) built 2017 and came into our possession 2018, 19 miles on the clock. We spent the 1st 12 mths exploring Europe including a lot of hard workin mountains etc, the next 6mths doing similar with breaks. since then shorter trips the longest being 8 weeks.

This year picked it up after a service and got the dreaded eml light with limpmode, turned around and straight back to dealer he plugged straight in and said it was an egr fault (didn't elaborate). I took it away without further problems until a short trip a few weeks later where we had a couple of occurrences but was able to pull over switch off and then restart without a problem, then researched and found this thread.

sorry for the long winded intro. Now the point I didn't have BD/software so have now got that though not had a chance to plug in and get readings. However I did have Millers (used occasionally) and started using better fuel as we were off to France for a couple of weeks just got on with it and suffered the occasional Limpmode (making observations as to when it happened). I realised it only happened when the engine was just coming up to working temperature and we hit a slope, never when fully up to temp. When I got back did some more digging and found 'Cataclean' as we were of to Italy a few days later took a chance and used it on the way (it has to be added with 15lt of fuel then run for at least 20mins you can then fill up) the treatment wasn't quite as it should have been but good enough. I had 2 limpmode episodes during the treatment in quick succession, we then spent 3 weeks driving down to and around the Dolomites (a lot of mountain climbing and short journeys + a lot of cheap diesel good stuff not available most of the time with Millers).

since getting back I have done another Catalean treatment, properly this time and we have had no further occurrences of the eml/limpmode, I am still using better quality fuel and adding millers and still not checked the ecu which I am sure is the old version.

Why did I choose Cataclean? doing a lot of research I came across it, it makes the claim (which I didn't see anywhere else) that is unique in that it will clean the cylinders, injectors, egr and Dpf. Bold claim but it does seem to have done the job and is dosed in a strong mix. To qualify I am an old school plant fitter (pre-ECU's & Computers) We also had a problem with the comfortmatic a couple of years ago (common apparently) and was told to spend Upwards of £5k changing parts etc,after doing a bit of old fashioned investigation upgraded and changed the battery and added a second earth strap £110, no more problems I like to dig before spending.

I appreciate this is a bit long-winded and may not help everyone but it is my experience and might be of assistance, at worst for £16 it's worth a try.

 

[kangexpress]

Hi all, (first post so not necessarily where it should be posted-apologies if not)

first of all a quick qualification of me and my situation, we have a Ducato based motorhome with comfortmatic (130 multijet) built 2017 and came into our possession 2018, 19 miles on the clock. We spent the 1st 12 mths exploring Europe including a lot of hard workin mountains etc, the next 6mths doing similar with breaks. since then shorter trips the longest being 8 weeks.

This year picked it up after a service and got the dreaded eml light with limpmode, turned around and straight back to dealer he plugged straight in and said it was an egr fault (didn't elaborate). I took it away without further problems until a short trip a few weeks later where we had a couple of occurrences but was able to pull over switch off and then restart without a problem, then researched and found this thread.

sorry for the long winded intro. Now the point I didn't have BD/software so have now got that though not had a chance to plug in and get readings. However I did have Millers (used occasionally) and started using better fuel as we were off to France for a couple of weeks just got on with it and suffered the occasional Limpmode (making observations as to when it happened). I realised it only happened when the engine was just coming up to working temperature and we hit a slope, never when fully up to temp. When I got back did some more digging and found 'Cataclean' as we were of to Italy a few days later took a chance and used it on the way (it has to be added with 15lt of fuel then run for at least 20mins you can then fill up) the treatment wasn't quite as it should have been but good enough. I had 2 limpmode episodes during the treatment in quick succession, we then spent 3 weeks driving down to and around the Dolomites (a lot of mountain climbing and short journeys + a lot of cheap diesel good stuff not available most of the time with Millers).

since getting back I have done another Catalean treatment, properly this time and we have had no further occurrences of the eml/limpmode, I am still using better quality fuel and adding millers and still not checked the ecu which I am sure is the old version.

Why did I choose Cataclean? doing a lot of research I came across it, it makes the claim (which I didn't see anywhere else) that is unique in that it will clean the cylinders, injectors, egr and Dpf. Bold claim but it does seem to have done the job and is dosed in a strong mix. To qualify I am an old school plant fitter (pre-ECU's & Computers) We also had a problem with the comfortmatic a couple of years ago (common apparently) and was told to spend Upwards of £5k changing parts etc,after doing a bit of old fashioned investigation upgraded and changed the battery and added a second earth strap £110, no more problems I like to dig before spending.

I appreciate this is a bit long-winded and may not help everyone but it is my experience and might be of assistance, at worst for £16 it's worth a try.

Diesel additives can be beneficial if you've used diesel from unspecified sources and want to clean the injectors and diesel fuel system afterward.

But are they really necessary?

I've driven some vans for over 1 million kilometers on the original engine without any chemical treatments, using only standard branded diesel fuel from reputable sources. I've never experienced any issues related to fuel quality.

I don't believe a fuel additive can mechanically clean an EGR system. The fuel is burned and turned into exhaust gases, so when the LP EGR is blocked, the exhaust will never pass through the blocked EGR.

The most common cause of a blocked DPF or EGR system is an improper fuel/air ratio during combustion, which produces black smoke.

No fuel additive can fix a mechanically defective injector, a broken turbocharger pressure hose, or a sensor giving false readings.

You'll always need to address the actual problems that are causing the symptoms.

 

[JDA]

Diesel additives can be beneficial if you've used diesel from unspecified sources and want to clean the injectors and diesel fuel system afterward.

But are they really necessary?

I've driven some vans for over 1 million kilometers on the original engine without any chemical treatments, using only standard branded diesel fuel from reputable sources. I've never experienced any issues related to fuel quality.

I don't believe a fuel additive can mechanically clean an EGR system. The fuel is burned and turned into exhaust gases, so when the LP EGR is blocked, the exhaust will never pass through the blocked EGR.

The most common cause of a blocked DPF or EGR system is an improper fuel/air ratio during combustion, which produces black smoke.

No fuel additive can fix a mechanically defective injector, a broken turbocharger pressure hose, or a sensor giving false readings.

You'll always need to address the actual problems that are causing the symptoms.

Appreciate what you are saying, however I can and did only write about my experience as it happened.

Sometimes things appear to go wrong but are down to the way the vehicle is used, rather than a specific fault. My experience may be useful to someone, in the short-term if not permanently.

It is now running as it always has.

 

[JDA]

Hi all, (first post so not necessarily where it should be posted-apologies if not)

first of all a quick qualification of me and my situation, we have a Ducato based motorhome with comfortmatic (130 multijet) built 2017 and came into our possession 2018, 19 miles on the clock. We spent the 1st 12 mths exploring Europe including a lot of hard workin mountains etc, the next 6mths doing similar with breaks. since then shorter trips the longest being 8 weeks.

This year picked it up after a service and got the dreaded eml light with limpmode, turned around and straight back to dealer he plugged straight in and said it was an egr fault (didn't elaborate). I took it away without further problems until a short trip a few weeks later where we had a couple of occurrences but was able to pull over switch off and then restart without a problem, then researched and found this thread.

sorry for the long winded intro. Now the point I didn't have BD/software so have now got that though not had a chance to plug in and get readings. However I did have Millers (used occasionally) and started using better fuel as we were off to France for a couple of weeks just got on with it and suffered the occasional Limpmode (making observations as to when it happened). I realised it only happened when the engine was just coming up to working temperature and we hit a slope, never when fully up to temp. When I got back did some more digging and found 'Cataclean' as we were of to Italy a few days later took a chance and used it on the way (it has to be added with 15lt of fuel then run for at least 20mins you can then fill up) the treatment wasn't quite as it should have been but good enough. I had 2 limpmode episodes during the treatment in quick succession, we then spent 3 weeks driving down to and around the Dolomites (a lot of mountain climbing and short journeys + a lot of cheap diesel good stuff not available most of the time with Millers).

since getting back I have done another Catalean treatment, properly this time and we have had no further occurrences of the eml/limpmode, I am still using better quality fuel and adding millers and still not checked the ecu which I am sure is the old version.

Why did I choose Cataclean? doing a lot of research I came across it, it makes the claim (which I didn't see anywhere else) that is unique in that it will clean the cylinders, injectors, egr and Dpf. Bold claim but it does seem to have done the job and is dosed in a strong mix. To qualify I am an old school plant fitter (pre-ECU's & Computers) We also had a problem with the comfortmatic a couple of years ago (common apparently) and was told to spend Upwards of £5k changing parts etc,after doing a bit of old fashioned investigation upgraded and changed the battery and added a second earth strap £110, no more problems I like to dig before spending.

I appreciate this is a bit long-winded and may not help everyone but it is my experience and might be of assistance, at worst for £16 it's worth a try.

Apologies for not giving a full reply originally it was quite late.

Your points are largely valid but not in all cases, as I said sometimes there is no underlying fault that needs dealing with.

However diagnostics in the modern computer driven world are not on the whole very accurate and there will be many owners on this and other threads who have been advised to and followed the OBD diagnostic route spending £100’s and even £1,000’s changing components in the fruitless pursuit of a solution when actually putting a decent cleaner through will clear the often small carbon build up causing the ECU to throw up a fault.

As I noted in the original post when we had a problem with the comfortmatic gb we would have spent over £5k following the flawed diagnostic interpretation.

Sometimes the simplest solution is the best solution and the cheapest.

 

[theoneandonly]

@JDA You are on one of the most important posts that indicate straight error codes are not always to believed, P0401 how many HPEGR valves have been incorrectly replaced when the problems is a blocked LPEGRcooler due to a cracked DPF.
Error codes are just an indicator to the area that a problem maybe, its not an invitation to get the parts cannon. Live data can pin down an problem area or indicate a sensor is working properly or not. I have 3 sensors not working properly do i replace them all or try to understand how the system works and find the location of 5V short or open on the earth line. With regards to understanding the importance of quality diagnostics you are amoungst the converted.
I Had a quick search on cataclean and are glad you have had a successfull use. I am not a specialist automotive chemist but I know enough to be wary of chemistry that survives combustion and would have an effect on the vital chemistry of the Cat DPF and sensors. Please read

6 Common Problems After Using Cataclean That You May Notice!

Problems after using Cataclean are rare, but they happen sometimes. Excessive product usage is just one of the most common reasons why ...

www.driversadvice.com

Ps Welcome to the forum.

 

[MSjoberg]

@MSjoberg @theoneandonly @Fredastaire According to FCA Service News 10.17.09 of 14/04/2009:
"Injectors:
The incorrect FBC value (Fuel Borne Catalyst or injection time correction factor) is analysed by means of EXAMINER
checking that the FBC of the single injector is comprised between -2 and +2 mm3/injet with the engine idling and
warm.
The incorrect FBC value generates the following problems:
-high particulate production-regeneration cannot be run.
Solution:
This problems may be solved in principle as follows:
-check correspondence between IMA injector codes and injector codes written in ECU.-try to reset self-learnt injection
amount.-replace the injectors."

So, at least that confirms the test is carried out with engine warm and at idle. And it seems that if outside that tolerance, the DPF regen cycle is prevented from occurring - probably as a safety control to prevent over fuelling on Post Injection and burning the DPF (the DPF just gets blocked instead!). But, that does not explain what is occurring for those with injectors within those test values.

If you are wondering where I found this info, it is buried in the following document which you can find in the "Downloads" section:

View attachment 449113

Thanks for posting this, very interesting! I think we really would like to find the corresponding document for X290 with dual EGR also....

I'm curious about what the injector corrections at normal driving tells us about the injectors behaviour during regeneration. I suppose that if overfueling during regen shall cause the DPF to overheat, it is the sum of injected fuel from all injectors that has to be to high? Now, if the result from test drives without regen taking place shows significant corrections (at RPM:s well above idle) for individual injectors but the sum for all 4 is close to zero, what (if any) conclusions can be drawn from that about the situation during a regen?


Plots of correction values vs RPM for an approx 40 minutes test drive with my 2018, town and countryside + short distance on highway:

1. All samples, from cold start:

The samples above approx 2500 RPM were obviously taken during pedal release and fuel cut-off at deceleration with downshifts.

2. Only samples with engine temperature higher than 75 DegC, averages for 25 RPM intervals:

(The first graph does not show the sum of all corrections, but it was close to zero also on individual sample level)

 

[deejays]

Thanks for posting this, very interesting! I think we really would like to find the corresponding document for X290 with dual EGR also....

I'm curious about what the injector corrections at normal driving tells us about the injectors behaviour during regeneration. I suppose that if overfueling during regen shall cause the DPF to overheat, it is the sum of injected fuel from all injectors that has to be to high? Now, if the result from test drives without regen taking place shows significant corrections (at RPM:s well above idle) for individual injectors but the sum for all 4 is close to zero, what (if any) conclusions can be drawn from that about the situation during a regen?


Plots of correction values vs RPM for an approx 40 minutes test drive with my 2018, town and countryside + short distance on highway:

1. All samples, from cold start:
The samples above approx 2500 RPM were obviously taken during pedal release and fuel cut-off at deceleration with downshifts.

2. Only samples with engine temperature higher than 75 DegC, averages for 25 RPM intervals:



(The first graph does not show the sum of all corrections, but it was close to zero also on individual sample level)

If you look back at page 54 where I posted the MES regen graph for my known (so far) good engine, you will see that the post injection is less then 0.2mm3/stroke, which is a factor of 10 less than the idle test tolerance. I consider your point valid and it would be desirable to have regens captured by more people - specially those with issues, so we can compare post injection quantities and also temperatures. I would imagine if injectors are outside the tolerance, then that may be an indication of post regen injection issues considering the relative amounts injected.

 

[theoneandonly]

@deejays @MSjoberg
a few graphs to answer and create a few questions. all my engine 130 manual V28 some historical ones and a recent regen.
@deejays you will see that the post injection is less then 0.2mm3/stroke,
my values are >.2-.8 mm3/stroke

DPF temperatures durring regen

Sorted by RPM

 

[theoneandonly]

A few more graphs from a regen last year a very specific set up. all other injector values are 0. Injection fuel quantity (post) is important as a single value that indicates when a regen happens.

Not all of the injector capabilities are used

Injection fuel quantity (pilot)​	Injection fuel quantity (pre)​	Injection fuel quantity (MAIN)​	Injection fuel quantity (after)​	Injection fuel quantity (post)​
mm³/i​	mm³/i​	mm³/i​	mm³/i​	mm³/i​
​	​	​	​	​

Injection advance (pilot)​	Injection advance (pre)​	Injection advance (MAIN)​	Injection advance (after)​	Injection advance (post)​
deg.​	deg.​	deg.​	deg.​	deg.​
​	​	​	​	​

Injection time (pilot)​	Injection time (pre)​	Injection time (MAIN)​	Injection time (after)​	Injection time (post)​
ms​	ms​	ms​	ms​	ms​
​	​	​	​	​

 

[Fredastaire]

@kangexpress I'm the guy who started this thread with 24k miles. I had my cooler changed 2 years back and now I'm seeing signs of it blocking at 38k miles.
You are probably aware that @theoneandonly and I converse regularly and swap notes. He gets template 4 csv files from me on a regular basis and has spotted that I have turbo lag; I've spotted high opening readings on the LP EGR.
.
High EGR readings means the EGR will be strangling the suction of the turbo which probably explains the lag.
.
For your current problem Ducato do you have template 4 csv files with and without the temp sensor?
.
I'm wondering if the files will show turbo lag as mine is doing.
.
I'm also wondering what the EGR temp sensor is for? I'm guessing to check that the exhaust temperature doesn't go high and melt the inlet manifold, (I've read another post somewhere about an owner having a melted pre turbo pipe).
.
I'm also wondering about your thoughts on a clean air pipe plumbing in where the temp sensor is currently. Maybe the EGR flexi pipe would need blanking off at the silencer to avoid any risk of high temp exhaust getting through and melting the manifold.
.
Comments appreciated.

 

[kangexpress]

@kangexpress I'm the guy who started this thread with 24k miles. I had my cooler changed 2 years back and now I'm seeing signs of it blocking at 38k miles.
You are probably aware that @theoneandonly and I converse regularly and swap notes. He gets template 4 csv files from me on a regular basis and has spotted that I have turbo lag; I've spotted high opening readings on the LP EGR.
.
High EGR readings means the EGR will be strangling the suction of the turbo which probably explains the lag.
.
For your current problem Ducato do you have template 4 csv files with and without the temp sensor?
.
I'm wondering if the files will show turbo lag as mine is doing.
.
I'm also wondering what the EGR temp sensor is for? I'm guessing to check that the exhaust temperature doesn't go high and melt the inlet manifold, (I've read another post somewhere about an owner having a melted pre turbo pipe).
.
I'm also wondering about your thoughts on a clean air pipe plumbing in where the temp sensor is currently. Maybe the EGR flexi pipe would need blanking off at the silencer to avoid any risk of high temp exhaust getting through and melting the manifold.
.
Comments appreciated.

I've logged data with and without the temperature sensor, but only for EGR and airmass parameters. I didn’t include turbocharger parameters since there hasn’t been any failure code related to turbocharger pressure yet.

I’ve got the updated software. In this scenario, it’s possible that turbocharger codes aren’t being triggered anymore because the issue might actually be due to a lack of airflow.

When the LPEGR is open, the fresh air supply is closed. Without fresh air and without air from the LP EGR cooler, the turbocharger will automatically slow down. Think of it like a vacuum cleaner: the turbine tries to suck in air, but if the pipe is blocked and no air can be drawn in, there will be no boost pressure. No air to suck means no boost from the turbine.

Another consideration is that the dirty air from the DPF entering the LPEGR and then going into the turbocharger isn’t good for the turbocharger. Over time, this will cause the turbocharger to wear out much faster than it should, eventually requiring replacement.

I suppose if the LPEGR cooler is already blocked, there may be no need for further blanking off. The LPEGR cooler is essentially already blanked off by the soot buildup, which is where the actual problem started.

 

[Fredastaire]

@kangexpress it's good that you understand the system as many people don't.
.
Can you do a new template 4 csv for @theoneandonly to interpret?

 

[Serrow225]

I've logged data with and without the temperature sensor, but only for EGR and airmass parameters. I didn’t include turbocharger parameters since there hasn’t been any failure code related to turbocharger pressure yet.

I’ve got the updated software. In this scenario, it’s possible that turbocharger codes aren’t being triggered anymore because the issue might actually be due to a lack of airflow.

When the LPEGR is open, the fresh air supply is closed. Without fresh air and without air from the LP EGR cooler, the turbocharger will automatically slow down. Think of it like a vacuum cleaner: the turbine tries to suck in air, but if the pipe is blocked and no air can be drawn in, there will be no boost pressure. No air to suck means no boost from the turbine.

Another consideration is that the dirty air from the DPF entering the LPEGR and then going into the turbocharger isn’t good for the turbocharger. Over time, this will cause the turbocharger to wear out much faster than it should, eventually requiring replacement.

I suppose if the LPEGR cooler is already blocked, there may be no need for further blanking off. The LPEGR cooler is essentially already blanked off by the soot buildup, which is where the actual problem started.

Hi , good point regarding early turbocharger wear , I did think that soot entering LP circuit could cause early engine wear , abrasive particles would effectively shot blast turbo blades , and valve steams , upper cylinder areas in combustion area ?

 

[Fredastaire]

@kangexpress reference the LP EGR temperature sensor recently removed, is this a two wire sensor or are there multiple wires?
.
im wondering if its possible to add a resistor to change the observed temperature to say 130 when its actually 100 degrees to see if the high temp would close down the egr opening value and stop the strangulation effect?