Technical 2018 Fiat Ducato Motorhme P041A-15 fault code

[dextron16]

2018 Fiat Ducato Motorhme P041A-15 fault code.

Its Euero 6 with twin EGR valves.

Engine light came on in France and the garage diagnosed EGR fault and changed the EGR. 200km down the road engine light back on but the van drove OK but did go into limp mode 4 times on the way back to the UK.

Message from Multiecuscan says P041A-15 Low pressure EGR Temperature sensor short to +V or open circuit.

My question is "where is this located" so at least I have a starting point.

Other thing I have noticed is that when this fault is present the radiator cooling fans do not come on when I park up even when coming of the motorway
which seems odd.

I have tested the fans and they work ok via Multiecuscan.

I dont want to start ripping things apart if I am just chasing a ghost here so I am going back out to see if the cleared faut returns when I activate the fans.
Anyone come across this before?
Will report back

Well a bit later in the day.
I ran multiecuscan again with the EGR temperature sensor on graph along with Engine temperature and Fan speed 1 and 2 as well.

Noticed that the fans didn't come on at all even though the temperature gauge was sat at normal when the engine temperature was 90C (see picture) according to multiecuscan. So maybe a fault with the dashboard or the temperature sender.

Low pressure EGR temp sensor seems to be reading fine so I don't know why it sometimes shows code P041A-15

I have also attached my Graph of parameters that I was checking.


Thanks

 

[the green vanper]

Hello,

Two docs from eLearn that should help.

 

[theoneandonly]

Is P041A-15 the only fault code?
The LPEGR temperature at about 30C is very low for known good engines and is typical of engines with a blocked lpegr cooler. Without further evidence i dont think this is the case but additional data will show valve working or not
I think looking at fan temperatures is a red herring. If you can do a 10 min run with the following template (warm engine this would help. we would be able to see if the LPEGR valve is doing as asked the error implies it is not. Unfortunately no voltages measured related to either egr valve.
Note this is specific for your need and different to the std template 4.

 

[theoneandonly]

Marked sensor is LPEGR temp sensor. this shows ECM connections

Not easy to get at. drop sub frame and 8 hrs plus or remove battery box view through hole, white arrow is temp sensor

Note as yet not identified LPEGR valve connections, the MES run with above template will identify if LPEGR is moving or if temp sensor an issue.

 

[dextron16]

Is P041A-15 the only fault code?
The LPEGR temperature at about 30C is very low for known good engines and is typical of engines with a blocked lpegr cooler. Without further evidence i dont think this is the case but additional data will show valve working or not
I think looking at fan temperatures is a red herring. If you can do a 10 min run with the following template (warm engine this would help. we would be able to see if the LPEGR valve is doing as asked the error implies it is not. Unfortunately no voltages measured related to either egr valve.
Note this is specific for your need and different to the std template 4.
View attachment 461323

Hello
Did a run with the template that you suggested and I have attached the results in a .csv file.
I now get Erro coded P0401-61 HP EGR VALVE BLOCKED and code P0402-61 SIGNAL CALCULATION FAILURE.
I dont know whats going on but it looks like I will have to change the HP RGR valve as this code keeps coming up but no light on the dash or limp mode after I cleared it which was on my second run which I have attached as well.
I hope that I can get some resolution. Oh the Temp sender and the fans was a bit of a red herring as during the first run the regen process started and the fans came on and ran when I pulled up.

 

[theoneandonly]

@dextron16 whatever you do , DO NOT replace the hpegr valve. Read these first i will look at your data a little later.

Twin EGR Problem

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

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]

Having fully looked at your data i can see a few things
1 you are suffering from LPEGR cooler syndrome ie the cooler is blocked and i wouldnt be surprised if the exhaust pipe is sooty please take piece of kitchen roll and wipe it out.
2 the lpegr max temperature @30 is the lowest ive seen it could be this that triggered the P041a-15 error
3 the dpf regeneration didnt completely finish the temperature 644 is OK 400 miles between regens ok
@Fredastaire
there is another thread on this subject its short only about 69 pages, you ought to read it and introduce your problem there as its the repository for egrcooler problems.

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

On Monday my Car will go to the Mechanic. I let them change the DPF, Injectors and the LPEGR Cooler. They will also clean the HPEGR. Is the anything else they should change? And, as my Ducato is on Fiat Software V28, is it better to contact a Fiat Dealer and make the Update to V31 after this...

www.fiatforum.com

so a few questions what software version have you got. F2 on MES

This graph is indicative of a blocked cooler
the valve varies between max an min with little area of control in the 1-3 mm region (see guide refered to earlier)
A typical good engine has max temp upto 160C (140C typical) and mean about 100C

 

[Fredastaire]

@dextron16 the main 69 page post (that I started) details all. I know it's a long haul but you do need to read it. In there it details that when you have a blocked cooler that the software trys to get the HP EGR to compensate for the inability of the engine to breath, the software gives a stupidly impossible high air volume request to the HP EGR, this impossible command leads to the software to give you an incorrect statement saying the HP is blocked. Fiat must make a fortune from garages changing the HP EGR. You will read that I went down that path, a waste of money.
.
You will also read that I have an idea (not yet tried) to add a resistor in parallel across the LP EGR temp probe wires to make the engine think the recirc exhaust is too hot and so close the LP EGR either partially or completely.
.
Here again I refer you to the main post, many pages back I detailed (Inc photos) the inside of the LP EGR. When the cooler blocks the LP EGR second device operates and a butterfly closes off the air from the air filter. If only we could stop the second device operating I rather think we can live with a partially damaged DPF.
.
I have a supply of resistors, wires, a plug/socket connector; just waiting for a warmer day to start playing. I've had another cooler fitted in December so I've no instant need to solve my problems. I've been hoping someone would beat me to it.
.
Perhaps @theoneandonly can comment.

 

[theoneandonly]

looking at your error message the air in to desired is 24% typicall seen with a bloocked cooler

 

[dextron16]

looking at your error message the air in to desired is 24% typicall seen with a bloocked cooler
View attachment 461632

Its starting to make more sense now, first LPEGR complains then later HPERG complains with either OV message or Signal out of range ?
I like the idea of the resistors many years ago when working on Caterpillar diesels hooked up to huge compressors we would get shutdowns on engine temp etc. No access to the ECU then, just call in the cat man. Problem was we were out at sea with no means to get him there. Downtime was not an option...So
We got around a lot of problems by using variable resistors on the sensors to overcome the problem, just keep tweaking until it starts up. Anyway its worth a shot if it can prevent this happening to people in the future.
Look forwards to hearing how it all goes.
Oh and I checked the exhaust pipe which is Sooty. So EGR cooler blocked or cracked.
Good job I have saved some of my pension for remedial work.
Thanks again for the help.

 

[theoneandonly]

Its starting to make more sense now, first LPEGR complains then later HPERG complains with either OV message or Signal out of range ?
I like the idea of the resistors many years ago when working on Caterpillar diesels hooked up to huge compressors we would get shutdowns on engine temp etc. No access to the ECU then, just call in the cat man. Problem was we were out at sea with no means to get him there. Downtime was not an option...So
We got around a lot of problems by using variable resistors on the sensors to overcome the problem, just keep tweaking until it starts up. Anyway its worth a shot if it can prevent this happening to people in the future.
Look forwards to hearing how it all goes.
Oh and I checked the exhaust pipe which is Sooty. So EGR cooler blocked or cracked.
Good job I have saved some of my pension for remedial work.
Thanks again for the help.

No problem.
to be honest this one was interesting and required stirring "the Little grey cells".

Good job I have saved some of my pension for remedial work.
I understand the feeling Ive a 2017 dUCATO and have been expecting/waiting for the airbag ecu to die , happened saturday evening so just hope the other shoe doesnt drop. (Cracked DPF).
As much as i enjoy the fault finding I HATE having to tell anyone this is going to cost serious wedge.

 

[dextron16]

No problem.
to be honest this one was interesting and required stirring "the Little grey cells".

Good job I have saved some of my pension for remedial work.
I understand the feeling Ive a 2017 dUCATO and have been expecting/waiting for the airbag ecu to die , happened saturday evening so just hope the other shoe doesnt drop. (Cracked DPF).
As much as i enjoy the fault finding I HATE having to tell anyone this is going to cost serious wedge.

I was prepared,,,, once the Engine light came o I knew the £££ would be going out faster that coming in.
The Airbag ECU on the van died 3 years ago, £280 swap/service/repair from Crash data. Took it out and sent it off two days later working one back. Hardest part of the job was getting the cup holder out of the way. Took about 30mins from start to finish. So far its not reared its ugly head again.
Been on the Fiat E-Learn tonight and downloaded a pdf file which shows how the LPEGR valve works and gets its calculation from, all intersting stuff.

Thanks again.

 

[dextron16]

OK LPEGR cooler has been replaced.....
Attached is a graph (Excel spread sheet) of the results and it looks like a success and a correct diagnosis. I have been on a 100 mile trip since and all seems well. No errors, no lights and the van is running better, Also the exhaust is cleaning up, the tail pipe has some soot in it but nothing compared to before I shall see in time if it goes completely or not.
Just want to say thank you to the guys who took their time in helping diagnose the true problem.

 

[theoneandonly]

@dextron16 thanks for the feedback. I would appreciate a copy of your csv file and if possible a list of what you replaced/ repaired purely to close the books on a successful outcome.

 

[dextron16]

@dextron16 thanks for the feedback. I would appreciate a copy of your csv file and if possible a list of what you replaced/ repaired purely to close the books on a successful outcome.

Hello
Find attached csv file, All that was replaced at present is the EGR Cooler., although a month before we had an egr valve replaced is France which didnt cure the problem.
The old EGR cooler which I have weighs about 3 x the weight of the new one tat was fitted. The guy who fitted it said that his software told him that the EGR cooler was blocked. I didn't question him on what system he used but I can ask.
He couldn't remove the cross member to access the DPF to remove it as the bolts were too tight and he was worried about breaking them even though he used an induction heater to try to remove them. He managed to move the DPF to one side and access the EGR cooler.
Anyway time will tell but I have faith.
Attached file for your perusal
Cheers

 

[Fredastaire]

@dextron16 hi, I'm the originator of the 80 page post on here so I've followed your post with interest. Your statement tonight is the first we've heard of being able to change the cooler without dropping the subframe. It's quite critical news for the rest of us.
Would it be possible to get more details from your engineer / mechanic as to how he achieved it? I'm wondering if he had to remove engine brackets to allow swinging the engine forwards?
I'm currently musing on ideas how to get at the LP EGR either to allow insitu cleaning the cooler and / or modify the EGR internal cam plate.
.
Anything you can find out will help many of us victims of blocked cooler syndrome.
.
@theoneandonly to monitor.
.
Kind regards

 

[dextron16]

@dextron16 hi, I'm the originator of the 80 page post on here so I've followed your post with interest. Your statement tonight is the first we've heard of being able to change the cooler without dropping the subframe. It's quite critical news for the rest of us.
Would it be possible to get more details from your engineer / mechanic as to how he achieved it? I'm wondering if he had to remove engine brackets to allow swinging the engine forwards?
I'm currently musing on ideas how to get at the LP EGR either to allow insitu cleaning the cooler and / or modify the EGR internal cam plate.
.
Anything you can find out will help many of us victims of blocked cooler syndrome.
.
@theoneandonly to monitor.
.
Kind regards

Hello
I will ask Jamie when I get back into town as to how he managed it, he did mutter something about taking off a few other bits but wasn't specific, I don't think he was in a good mood.
I will find out.
Cheers

 

[Fredastaire]

@dextron16 , thanks.
It really is important for our world colleagues suffering blocked cooler syndrome to find easier ways to get around the problem.

 

[dextron16]

@dextron16 , thanks.
It really is important for our world colleagues suffering blocked cooler syndrome to find easier ways to get around the problem.

I spoke to Jamie today and he was a bit vague on how he did it, he said he just undid bits until he could move the DPF asides, his words not mine.
But the proof in the pudding is that it is possible to do without removing the subframe. He was adamant that he could not undo the bolts that held the subframe in place without breaking at least one of them.
Sorry can't be more specific he's a busy man and does hundreds of vehicle's in a week.
Sorry again.