Technical Error code P0236 & 0238

[theGman]

My saga continues. After the Fiat garage said the fault was fixed the motorhome went into limp mode again with check engine and EML. This happened after 200 miles of my European road trip. I reset it with my code reader and attached the reader to record live data if a DTC came up. I’ve attached the screen grabs. Any help would be great

 

[theoneandonly]

My saga continues. After the Fiat garage said the fault was fixed the motorhome went into limp mode again with check engine and EML. This happened after 200 miles of my European road trip. I reset it with my code reader and attached the reader to record live data if a DTC came up. I’ve attached the screen grabs. Any help would be great

If it saves data as a csv or text file post it here and someone (me!) Will have a look.

 

[jackwhoo]

Hi,

Sorry you are still having problems.

Unfortunately you haven't provided details of the code that caused the mil light and limp mode or details of what your fiat garage did to "fix" the fault before handing the vehicle back to you. So we are in the dark.

Best wishes

J

 

[jackwhoo]

The only thing I can see from the limited data shown is the barro pressure and map pressure are nearly identical which I would only really expect to see if there was very little or no load on the engine.

 

[jansla]

Hello, I seem to have a similar problem. Mine is 2018, 2.3 with comfortmatic with 50000km on the clock. I own it 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? Nearly 1000km tht day, so time to rest. Next morning after erasing of 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 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. Two different shops to be exact. 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 80-100 km/h. Managed to come back home. After studying forum changed the MAP sensor and solenoid valve, both new 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?

 

[CheeseMonster]

Hello, I seem to have a similar problem. Mine is 2018, 2.3 with comfortmatic with 50000km on the clock. I own it 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? Nearly 1000km tht day, so time to rest. Next morning after erasing of 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 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. Two different shops to be exact. 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 80-100 km/h. Managed to come back home. After studying forum changed the MAP sensor and solenoid valve, both new 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?

I think you should inspect the wiring loom for damage all the way to the ECU. Where it is wrapped in tape the individual wires look vulnerable to chafing or breaking to me.

Using a diagnostic tool does the requested signal match the actual signal?

 

[Fredastaire]

Please may I ask you to read https://www.fiatforum.com/threads/ducato-p0401-p0402-p0236-p0238-and-limp-mode-its-2017-euro-6-egr-changed-what-do-i-check-next. I started this post and have had much assistance from @theoneandonly once read then i invite you to add your details to it.
Without any doubt you need to buy Multiecuscan and install to a laptop, cost circa £100 then you can fully interrogate your engine whist it's running to view various pressures and temperatures to see if the actual values follow the ECU required values. You can also establish the ECU actual update version.
Your fault effects echo mine. I at this stage suspect you have the 'blocked LP EGR cooler' syndrome, although it would be well worth checking the intercooler pipes for damage / air leaks and check the air filter for rodents nests (mice).
Simple question - if you use a paper kitchen towel and wipe out the exhaust silencer tailpipe, does it come away nearly clean or rather sooty?
.
When you have bought Multiecuscan the 'theoneandonly' and myself can assist further.
.
Kind regards

 

[CheeseMonster]

Please may I ask you to read https://www.fiatforum.com/threads/ducato-p0401-p0402-p0236-p0238-and-limp-mode-its-2017-euro-6-egr-changed-what-do-i-check-next. I started this post and have had much assistance from @theoneandonly once read then i invite you to add your details to it.
Without any doubt you need to buy Multiecuscan and install to a laptop, cost circa £100 then you can fully interrogate your engine whist it's running to view various pressures and temperatures to see if the actual values follow the ECU required values. You can also establish the ECU actual update version.
Your fault effects echo mine. I at this stage suspect you have the 'blocked LP EGR cooler' syndrome, although it would be well worth checking the intercooler pipes for damage / air leaks and check the air filter for rodents nests (mice).
Simple question - if you use a paper kitchen towel and wipe out the exhaust silencer tailpipe, does it come away nearly clean or rather sooty?
.
When you have bought Multiecuscan the 'theoneandonly' and myself can assist further.
.
Kind regards

If the LP EGR cooler is blocked what is to stop one disconnecting it at the highest point and filling it (in situ) full of Launch DPF cleaner and then blowing it through with an airline?

 

[Fredastaire]

You physically cannot get at the cooler, It's hidden at the back of the engine under the DPF/ cat unit.
I've cleaned my removed cooler with caustic soda. Easy and quick.
To get the cooler off first you detach the lower front suspension, detach the front subframe, disconnect the steering rack leaving it dangling on its hydraulic hoses. Only now can you reach the DPF. So with the DPF removed now you can see the cooler.
I would like to try something radically different.
Find a way to immobilise the butterfly throttle that's inside and integral the LP EGR body. Leave the blocked cooler as is.

 

[theoneandonly]

If the LP EGR cooler is blocked what is to stop one disconnecting it at the highest point and filling it (in situ) full of Launch DPF cleaner and then blowing it through with an airline?

As @Fredastaire says its covered by the dpf but if it was ever removed you could always have a tube welded to the cooler for subsequent cleaning with better access .
Cooler on left, lpegr on left of green ring.

Edit both are not on left cooler is on right.

 

[Fredastaire]

If I may correct, the egr is on the far left, the rectangular stainless box (with a label), on the right, is the cooler. The photo might suggest that you can reach this cooler, fact is that this engine is devoid of the DPF and the turbo, these latter two items well and truly hiding the cooler.
.
The egr in the photo has the black plastic cover inside which are the two electric servo motors. One opens and closes the LP EGR valve, the other controls a disc butterfly throttle. The idea is that when the engine calls for dirty exhaust to ingest that the butterfly closes off the clean air supply from the air filter thus giving a blend of clean air and dirty exhaust into the turbo inlet. With a blocked cooler the butterfly closes off the fresh air thus the engine is strangled as it cannot breath. Bingo the engine complains and throws fault codes and sometimes Limp Mode.
.
With the use of Multiecuscan and a drive you can see the LP EGR opening plus watch the LP EGR temperature, thus you can observe if you have a blocked LP EGR cooler.

 

[CheeseMonster]

If I may correct, the egr is on the far left, the rectangular stainless box (with a label), on the right, is the cooler. The photo might suggest that you can reach this cooler, fact is that this engine is devoid of the DPF and the turbo, these latter two items well and truly hiding the cooler.
.
The egr in the photo has the black plastic cover inside which are the two electric servo motors. One opens and closes the LP EGR valve, the other controls a disc butterfly throttle. The idea is that when the engine calls for dirty exhaust to ingest that the butterfly closes off the clean air supply from the air filter thus giving a blend of clean air and dirty exhaust into the turbo inlet. With a blocked cooler the butterfly closes off the fresh air thus the engine is strangled as it cannot breath. Bingo the engine complains and throws fault codes and sometimes Limp Mode.
.
With the use of Multiecuscan and a drive you can see the LP EGR opening plus watch the LP EGR temperature, thus you can observe if you have a blocked LP EGR cooler.

I just wondered if it was possible to separate the pipe highlighted in red at the front of the engine a couple a couple of millimeters to inject cleaner which would flow down into the cooler? Or is that a coolant pipe?

Hopefully with Millers and v32 software I won't have problems although it doesn't stop me worrying.

 

[Fredastaire]

@CheeseMonster you've got me on that pipe. I'll have to see if I've got it. That pipe is on the 'after filter' side of the cooler. I wonder where is going to?

 

[Fredastaire]

@CheeseMonster that pipe is a water pipe that goes via a rubber hose at the top of the engine to the bulkhead heater connection.
.
The other option. I've wondered about us to connect the cooler inlet bottom flexi via a pipe to the air filter and blank off the silencer connector so the LP EGR only ever sucks clean air.

 

[CheeseMonster]

@CheeseMonster that pipe is a water pipe that goes via a rubber hose at the top of the engine to the bulkhead heater connection.
.
The other option. I've wondered about us to connect the cooler inlet bottom flexi via a pipe to the air filter and blank off the silencer connector so the LP EGR only ever sucks clean air.

I had to read your option idea a number of times but I see what you are getting at. It sounds feasible to me and I'll give it some thought.

 

[Fredastaire]

@CheeseMonster , I've now run the last year only using the expensive diesel AND Millers in the hope that best combustion will produce less soot.
I'm just wondering how long I've got before the cooler blocks again.
I don't fancy letting a remapper guy loose on my van because they don't know about twin EGRs/ v28 / v32; there would be the risk of them installing something different.
Yet again this morning I've had the bonnet up to view for inspiration..... Option 1 unclip the connector to the LP EGR, undo the harness wrapping to allow re-clipping to a second hand LP EGR that would be an ineffective dummy sited in fresh air, (to leave the ECU thinking it's doing something), option 2, remove the butterfly disc, (garage job a day on a ramp, if it doesn't work it's yet another day to reinstall - so risky expensive); option 3 would be the pipework mod to always breathe fresh air. I've seen photos of it being done somewhere eastern Europe where the person just put some gauze over the flexi end, that leaves the EGR sucking mucky outside unfiltered air from the van underside, (pity the turbo) and pistons).
Overall it's the problem that the diy mechanic is stuck because of the front suspension/ subframe removal difficulties.

 

[CheeseMonster]

@CheeseMonster , I've now run the last year only using the expensive diesel AND Millers in the hope that best combustion will produce less soot.
I'm just wondering how long I've got before the cooler blocks again.
I don't fancy letting a remapper guy loose on my van because they don't know about twin EGRs/ v28 / v32; there would be the risk of them installing something different.
Yet again this morning I've had the bonnet up to view for inspiration..... Option 1 unclip the connector to the LP EGR, undo the harness wrapping to allow re-clipping to a second hand LP EGR that would be an ineffective dummy sited in fresh air, (to leave the ECU thinking it's doing something), option 2, remove the butterfly disc, (garage job a day on a ramp, if it doesn't work it's yet another day to reinstall - so risky expensive); option 3 would be the pipework mod to always breathe fresh air. I've seen photos of it being done somewhere eastern Europe where the person just put some gauze over the flexi end, that leaves the EGR sucking mucky outside unfiltered air from the van underside, (pity the turbo) and pistons).
Overall it's the problem that the diy mechanic is stuck because of the front suspension/ subframe removal difficulties.

Option 3 sounds the easiest, could you fit a little K&N filter onto the egr cooler? Is there still a chance the egr valve could still fail throwing an error code. I assume lpegr sends position info back to the ECU?

 

[Fredastaire]

If the modification is done with a 'not blocked' cooler then the LP EGR will function by sucking fresh air. The various fault codes occur from the map device in the inlet manifold because the turbo is unable to achieve the pressures that the ECU has requested. Whatever we think of as a 'get around' we are stuffed because you can't get at the cooler, it's so well hidden you can't simply fit a knr filter to it's inlet.

 

[theoneandonly]

Just to show how well hidden , wheres wally i mean the cooler.
Its behind the DPF. The main clue is the coolant pipework questioned by @CheeseMonster

 

[jansla]

Please may I ask you to read https://www.fiatforum.com/threads/ducato-p0401-p0402-p0236-p0238-and-limp-mode-its-2017-euro-6-egr-changed-what-do-i-check-next. I started this post and have had much assistance from @theoneandonly once read then i invite you to add your details to it.
Without any doubt you need to buy Multiecuscan and install to a laptop, cost circa £100 then you can fully interrogate your engine whist it's running to view various pressures and temperatures to see if the actual values follow the ECU required values. You can also establish the ECU actual update version.
Your fault effects echo mine. I at this stage suspect you have the 'blocked LP EGR cooler' syndrome, although it would be well worth checking the intercooler pipes for damage / air leaks and check the air filter for rodents nests (mice).
Simple question - if you use a paper kitchen towel and wipe out the exhaust silencer tailpipe, does it come away nearly clean or rather sooty?
.
When you have bought Multiecuscan the 'theoneandonly' and myself can assist further.
.
Kind regards

@Fredastaire Thank you for your kind invitation to join your thread, I’ll post my case there of course. After reading all that thread I’m scared that it may cost a fortune! Well in my case there is P0238 and P0236 but no 401 neither 402 but a lot of similarities anyway. I have bought the Multiecuscan, but made a mistake choosing iPhone version. Fri version - not working. Paid 60Eur/year - not much better. Suddenly stops working, freezes - useless on IOS 16. Unfortunately the last time I had Windows laptop/PC was 20 years ago so I had to first find a solution for this. So now paid for Multiecuscan for Windows and played a little with it. When I register boost pressure (yellow) and desired boost pressure (green) it’s nearly always a gap between those two. Is it normal that actual pressure is not reaching the desired one?

And now to your question about 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.