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

[theoneandonly]

On another thread the parts availability was raised Concidering these models were only made for 3 years and i've just read a thread about availability of parts for mainstream models 17 years old should we be concidering our options. How many people have actually changed or had changed the HPEGR and LPEGR valves due to these issues. what consumables are specific to this model.

 

[jansla]

Hello, Posting my story after invitation from @Fredastaire. It looks like I have a similar problem to what was broadly discussed in this thread. Mine is 2018 motorhome, 2.3 engine, Marelli 9DFCF6/EOBD, soft ver.0024, 2xEGR with comfortmatic and 50000km on the clock. I owe this from brand new. No problems until this summer. After driving the whole day through the A7 in Germany suddenly P0238 and P0236 fault codes and limp mode. I was doing about 90-100 km/h just a little uphill at that time, close to the Austrian border. It was late evening, took first exit from the motorway, connected OBD2 scanner. Erased the fault codes and everything was normal, I could drive as usual. After another 50km same thing again. Erased codes could drive further. After another 5km same thing, P0238 and P0236 and limp mode. It was late at night. I took nearest tankstelle for a night rest. Was it too much for the engine that day? Nearly 1000km so time to rest. Next morning after erasing fault codes on my way again, but after only 20km same problem again. Well that was enough.
Probably some defect in the boost - so I called assistance and they towed me to their base at Lermoos. They could not find any obvious defect so we were stranded at their yard until Monday. The nearest shop was in Garmisch, Germany so towed back to Germany the day after. They were busy on Monday so first on Tuesday afternoon they could have a look and the verdict was: everything works as it should, they erased codes and said Hello after charging 120eur fot the test. Their recommendation was to drive on, and erase fault code if it came on again. So I did it, and needed to erase code after another 150km. Luckily passing Brennerpass was without limp mode. After reaching Italy (Fiat’s homeland) I found the Fiat Professional service. They connected to OBD and said everything is ok. Well it was - after erasing the codes. At that point I have reached my destination in Italy so I stayed one week. Later drove further and there were several days without any problem. But after couple of days same thing happened again several times. Never at idle, never when accelerating, never downhill, and never when going very steep uphill. Each time at about 80-100 km/h. Managed to come back home. After studying forum changed the MAP sensor and solenoid valve behind that black vacuum box, both new and exact same part number (Bosch and Pierburg respectively). All tubes keep vacuum even after one day. On the road again and after only 5km same problem and fault codes. Stopped. Erased and could drive for 1200km without any issue. Here in Sweden we usually say in such a situation “skägg i brevlådan” which means that I’m sitting with my “beard in a letterbox” even if I really do not have a beard, but anyway stuck. Is there anything more I could try myself before leaving the car to the shop for expensive changing of different parts?

There is one more thing (may or may not be related): Until this summer there was no need to add any coolant. Was the same level during 4 years even driving in Italy on July several times. This year had to top-up about half a liter and 4 weeks later another 250ml. Am I loosing coolant at a faulty LP-EGR cooler or just a coincidence?

Following @Fredastaire’s advice checked out the tailpipe. Kitchen towel comes off it, richly loaded with rather dry (not oily at all) black soot, which can be rather easily brushed off the towel (at least excess of it) as fine and dry black powder. Not good.

 

[theoneandonly]

Am I loosing coolant at a faulty LP-EGR cooler or just a coincidence?

The lpegr cooler does have a coolant flow so is possible and difficult to see.
Its more likely to bee seen at the front.

From your post it is evident you have "lpegr cooler syndrome" or a 401 without the 401 code.
WIth data collected with multiecuscan (or alfaobd) i can confirm the issues and asses if the hp and lpegr valves still work.
What software version do you have? Please confirm what it version it is before being updated (if required).
I can hapily supply the relevant test templates for multiecuscan.

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

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

 

[jansla]

@theoneandonly thank you for your comment! My software version is 0024 as shown by Multiecuscan.

@Fredastaire Thank you very much for your advice regarding registration of LP-EGR parameters. Back home after a short ride with Multiecuscan connected. Could not record the whole in one file as my software (or hardware) has crashed several times. Here comes what I could save. Is it enough data to be able to say if my LP.EGR is faulty?

Thank you very very much in advance for help and advice!

 

[theoneandonly]

From your graph its too short a period to tell if the lpegr is working as required, was the engine upto temperature? The cooler temperature is far to low (if engine is upto temp) i will check your data later.
The actual lpegr opening does tend to vary mostly max to min, classic problematic activity.

 

[Fredastaire]

I can only see with difficulty on my small phone screen.What I can read is the LP EGR temperature never gets above 61 degrees, dramatically low plus the EGR opening is 4.8 max, that's fully open. We will await @theoneandonly to give proper comments. My initial response is that your cooler is blocked.....have you pm'd me with your email address?

 

[jansla]

@theoneandonly yes the engine was at usual working temperature
@Fredastaire yes I've started a conversation with e-mail address

I will try to make better (longer) recording of lp.egr data tomorrow

 

[theoneandonly]

The mean temperature is low the max is low the valve doesnt swing totally min to max there is still some control ie not the worst. You have a problem at the earliest stage I've seen. I would like your next run to include the differential pressure sensor this tells a lot more than the Particulate filter clogging.
What i see here is an LPegr valve that is still working not yet clogged or sticking and probably does not need replacing yet. A clean when the cooler is replaced wouldnt go amiss (if done sooner rather than later.)

 

[jansla]

@theoneandonly Thank you very very much for analysing my data! And for commenting that of course as well. Today I have managed to record some more, just between some errors and suspendings of Multiecuscan tool. Could you please look at this as well?

 

[theoneandonly]

The differential dpf sensor shows the dpf is on its way to being blocked and not regenerating as required, probably less than every 200 mile ( one a bit worse was regen every 70 miles before cleaning.
The DPF is cracked (paper towel test shows this). the cooler is not yet blocked.
Need data on Injectors

 

[CheeseMonster]

The differential dpf sensor shows the dpf is on its way to being blocked and not regenerating as required, probably less than every 200 mile ( one a bit worse was regen every 70 miles before cleaning.
The DPF is cracked (paper towel test shows this). the cooler is not yet blocked.
Need data on Injectors

View attachment 429226


View attachment 429227

@theoneandonly . Can you explain the second graph, LPEGR cooler please. I can see that the DPF is clogged (from Mr.O'Riley) from the high pressure but not sure what to look for in the second graph.

 

[theoneandonly]

Right o an explanation
for first paqrt i wrote this last year

DPF Differential Pressure sensor Diagnosis with MES

How to diagnose a problem the DPF Differential Pressure sensor and its impact on the DPF. known in mes parameter list as Differential Pressure Sensor. These sensors are prone to any debris or condensation in the exhaust, which can cause the...

www.fiatforum.com

What is an acceptable figure for DPF Differential Pressure (measured in mbar)? The answer is as little as possible. But if it flatlines at zero its dead.
Adding back pressure will make the engine work harder, and use more fuel to deliver the same power.

<20 Brilliant DPF causing almost no restriction
20-99 Good result and typical of a DPF in good working order
100-250 DPF causing up to 0.25 BAR of pressure – needs investigation
250-500 Serious restriction probably not allowing car to do a Forced Regen
500-1000 Performance loss very marked at this level
>1000 Car can’t pull the proverbial skin off a rice pudding. All your boost is stuck in the DPF example graphs are in the guide.

for the LPEGR some more examples are in

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

I tend to use the same scale on the Y axes to make comparisson easier.
The green line at 4.7 is what i perceived to be the maximum opening of the valve. Some of the poorly examples jump between 4.7 and zero. I have examined data for over 15 engines and would be to have a look at more including well running examples. The value of cooler temperature does vary from van to van as well as condition. A Max value of good engines can be 140 to 160. The mean value i use is the mean of a warm engine. I have examples of A road variability and 60mph Motor way runs.
The valve of a properly running engine can vary from mid positions 1-3mm as well as max to min
The above is a interesting example as it shows normal valve movement and is not yet throwing a 401 . Good examples have a mean over 100 and maximums over 120. But the DPF is close to not being able to regen. The kitchen paper test shows the DPF is cracked or melted.
@CheeseMonster is that sufficient explanation no i've just thought of something.
Why does the cooler exist

Combustion gases are recirculated into the induction cycle and need to have temperature reduced from the 3-600 degrees in the exhaust. Why is it controlled in the 100-140C region?
That's enough for now.

 

[CheeseMonster]

Right o an explanation
for first paqrt i wrote this last year

DPF Differential Pressure sensor Diagnosis with MES

How to diagnose a problem the DPF Differential Pressure sensor and its impact on the DPF. known in mes parameter list as Differential Pressure Sensor. These sensors are prone to any debris or condensation in the exhaust, which can cause the...

www.fiatforum.com

What is an acceptable figure for DPF Differential Pressure (measured in mbar)? The answer is as little as possible. But if it flatlines at zero its dead.
Adding back pressure will make the engine work harder, and use more fuel to deliver the same power.

<20 Brilliant DPF causing almost no restriction
20-99 Good result and typical of a DPF in good working order
100-250 DPF causing up to 0.25 BAR of pressure – needs investigation
250-500 Serious restriction probably not allowing car to do a Forced Regen
500-1000 Performance loss very marked at this level
>1000 Car can’t pull the proverbial skin off a rice pudding. All your boost is stuck in the DPF example graphs are in the guide.

for the LPEGR some more examples are in

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

View attachment 429237
I tend to use the same scale on the Y axes to make comparisson easier.
The green line at 4.7 is what i perceived to be the maximum opening of the valve. Some of the poorly examples jump between 4.7 and zero. I have examined data for over 15 engines and would be to have a look at more including well running examples. The value of cooler temperature does vary from van to van as well as condition. A Max value of good engines can be 140 to 160. The mean value i use is the mean of a warm engine. I have examples of A road variability and 60mph Motor way runs.
The valve of a properly running engine can vary from mid positions 1-3mm as well as max to min
The above is a interesting example as it shows normal valve movement and is not yet throwing a 401 . Good examples have a mean over 100 and maximums over 120. But the DPF is close to not being able to regen. The kitchen paper test shows the DPF is cracked or melted.
@CheeseMonster is that sufficient explanation no i've just thought of something.
Why does the cooler exist
View attachment 429244
Combustion gases are recirculated into the induction cycle and need to have temperature reduced from the 3-600 degrees in the exhaust. Why is it controlled in the 100-140C region?
That's enough for now.

Thanks for your thoughts and explanation.
So questions remain:
How do you stop the cooler clogging?
If the DPF has collected the soot particles why are they getting into the cooler?
I guess that brings us back to @Fredastaire his previous thoughts on getting fresh air into the cooler.

 

[theoneandonly]

Thanks for your thoughts and explanation.
So questions remain:
How do you stop the cooler clogging?
If the DPF has collected the soot particles why are they getting into the cooler?
I guess that brings us back to @Fredastaire his previous thoughts on getting fresh air into the cooler.

plenty of finger trouble with this one so may run out of edit time
Why do we get excessive sooting: overfuelling either by dodgy program or dodgy injectors get latest program update. Injectors contaminated either by programming defects or contaminated fuel. keeping injectors clean is important here options Premium fuel, additives like Miillers eco or dedicated cleaners like Liqui Moly Diesel Purge. Fuel filter is important here, i know of one example of 401 problem having diesel bug implicated.
Why does cooler soot up? Well first of all the soot has to get out of the DPF. With initial overfueling excessive temperatures are generated in the DPF (greater than 800C which causes cracking and an easy path for soot through the DPF. Temp up to 620 during regen.) The stardard path of exiting DPF is exhaust and LPEGRcooler circuit
How to stop cooler clogging: new DPF, stop injectors ovefueling (new injectors, update program, fuel cleaning). Alternatives are being discussed.
Note The turbo solenoid MAP sensor and Differential DPF sensor all important in this setup.

Edit above schematic modified by Fredastaire

 

[Fredastaire]

1/. The above report by @theoneandonly is,I concur, 100% correct.
2/. If only we could find a way to render the LP EGR butterfly throttle inactive we need not worry about the soot blockage - leave it blocked.
.
The problem is this butterfly component is totally hidden and cannot be reached without a garage h hoist as it's a subframe off job.

 

[CheeseMonster]

1/. The above report by @theoneandonly is,I concur, 100% correct.
2/. If only we could find a way to render the LP EGR butterfly throttle inactive we need not worry about the soot blockage - leave it blocked.
.
The problem is this butterfly component is totally hidden and cannot be reached without a garage h hoist as it's a subframe off job.

Is the LP EGR valve a stepper motor?
Is there some form of feedback sent from the LP EGR valve to the ECU?

 

[theoneandonly]

Is the LP EGR valve a stepper motor?
Is there some form of feedback sent from the LP EGR valve to the ECU?

I presume so.
Yes, in that you can read actual position.and others
Edit are you thing force the butterfly open or closed?
We need a wiring diagram and pin outs for the ecu plugs

 

[CheeseMonster]

I presume so.
Yes, in that you can read actual position.and others
Edit are you thing force the butterfly open or closed?

If the stepper motor was replaced by a resistor. Then count the drive pulse sent to the resistor and return a DC voltage for the feedback signal, would this satisfy the ECU? Or is it more complicated than that?

If fresh air was fed back to the engine instead of cooled exhaust gases would the engine run hotter?

 

[theoneandonly]

If the stepper motor was replaced by a resistor. Then count the drive pulse sent to the resistor and return a DC voltage for the feedback signal, would this satisfy the ECU? Or is it more complicated than that?

If fresh air was fed back to the engine instead of cooled exhaust gases would the engine run hotter?

Short answer i dont know. Bring your van up here with a wiring diagram and we can stick a scope on it.



ANYBODY got a wiring diaggram schematic anything for the x290 twin egr, even pin outs for ecu.
I also need to know the crankshaft sensor pin. Or an easy acess point.

 

[CheeseMonster]

Short answer i dont know. Bring your van up here with a wiring diagram and we can stick a scope on it.

Unfortunately I don't have a wiring diagram or a spare LP EGR valve I can look at.