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

[theGman]

The saga continues. The Fiat garage called my wife yesterday, told her all injectors have been replaced. Error code remains. They suspect the ecu now, not covered by warranty. They said they will have to talk to Fiat Italy for guidance. This maybe a crazy idea but is it possible a faulty ecu could cause the injectors to over fuel and cause an injector tip to blow off?

 

[BoultsG]

@theoneandonly I have a couple of errands this morning is there any more/ alternative data I can capture to assist with diagnostics ?

 

[CheeseMonster]

Intake air quantity​

Desired intake air quantity​

Boost pressure​

Desired boost pressure​

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​

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@theoneandonly I have attached file of our trip down the M27 today. Hopefully it gives you some useful info.

 

[theoneandonly]

@theoneandonly I have a couple of errands this morning is there any more/ alternative data I can capture to assist with diagnostics ?

Try template 9 for 30 seconds (semi static variables) then template 4.

 

[theoneandonly]

@CheeseMonster
The rogue results are interesting

The Boost pressure generally follows the desired. Is this difference real or due to time delay of measuring

 

[jackwhoo]

The saga continues. The Fiat garage called my wife yesterday, told her all injectors have been replaced. Error code remains. They suspect the ecu now, not covered by warranty. They said they will have to talk to Fiat Italy for guidance. This maybe a crazy idea but is it possible a faulty ecu could cause the injectors to over fuel and cause an injector tip to blow off?

Hi,
If those are the injectors from your current engine , the engine needs to to stripped to check how much damage caused by the bits of injector in engine while it was running.
You have had a saga of problems . If caused by ecu then it should be covered by warranty because faults occurred during warranty period. If Fiat incorrectly diagnosed the fault previously that is by the way.

Best wishes

Jack

 

[theGman]

Hi,
If those are the injectors from your current engine , the engine needs to to stripped to check how much damage caused by the bits of injector in engine while it was running.
You have had a saga of problems . If caused by ecu then it should be covered by warranty because faults occurred during warranty period. If Fiat incorrectly diagnosed the fault previously that is by the way.

Best wishes

Jack

From my invoice , four new injectors were fitted to the new engine.

 

[CheeseMonster]

@CheeseMonster
The rogue results are interesting
View attachment 431081

View attachment 431082

View attachment 431083

View attachment 431084
The Boost pressure generally follows the desired. Is this difference real or due to time delay of measuring

View attachment 431085

When I get round to it I intend to build my own data logger, initially a Pi then then transfer it to Arduino so I can have full-time data logging. Hopefully that will give better logging.

Why does my Turbo actuator command sit around 96% and BoultsG sits around 56%?

 

[BoultsG]

@theoneandonly my new OBD adapter arrived this afternoon, supposedly able to record 30 PID's !! a test will see. We have our windows screen booked for a replacement tomorrow AM. With the new adapter which templates would you suggest running?

Regarding today's as I was using my older OBD adapter, I ran template 3 from the list you provided earlier. Not sure if it will help but in case I have attached the results. The second file triggered the 401 & 402.

 

[CheeseMonster]

@theoneandonly my new OBD adapter arrived this afternoon, supposedly able to record 30 PID's !! a test will see. We have our windows screen booked for a replacement tomorrow AM. With the new adapter which templates would you suggest running?

Regarding today's as I was using my older OBD adapter, I ran template 3 from the list you provided earlier. Not sure if it will help but in case I have attached the results. The second file triggered the 401 & 402.

So both our Turbo Actuator Command start at about 95% with the engine at 0rpm. As soon as your engine starts it goes to 54%, mine stays at 95% most of the time!

 

[BoultsG]

An interesting morning and probably the worst I have had in a while. For the last 2 days I ran the engine at idle for around 10 to 20 minutes, began a journey and may or may not have triggered any error codes. those that were triggered were 401 & one 402 error.

This morning I setup template 9 and ran the engine on idle for around a minute (File1). Loaded up template 4 and started our journey. Within a mile a 238 error was triggered (File2). Within another mile another 238 was triggered (File3). About 3 miles further on a 401 & 402 error was triggered (File4). The rest of our journey was ok with no error codes triggered (File5). I am assuming that my next course of action is to replace the EGR Cooler as previously done by @Fredastaire. Though I will wait for confirmation from @theoneandonly before I do.

 

[Fredastaire]

Most of our readers just have no knowledge of whats inside the LP EGR and what happens so let try and give an idea:-
.
Get your Wife to run down the road, you are with her holding a scarf. Wrap the scarf around her neck and begin to pull tight, she will complain (fault codes); pull a lot tighter so she cannot breath, she will collapse and stop (Limp mode). Let go (clear the codes) and she will recover and run again. This is the function of the LP EGR if the cooler is soot blocked.
.
Now look at the photo of the LP EGR unit. It has an infeed hole with a butterfly fully open. it has another infeed hole blocked by the EGR flap. the outfeed hole goes to the turbo inlet.
In the photo ive marked the (single) electric motor pinion. this drives the reduction gear, hidden behind is the gear that drives the EGR flap pivot shaft. On the EGR gear is screwed a black metal cam plate. running in the profile slot of the cam plate is ballrace on an arm of the butterfly drive shaft.
.
When the ECU calls the LP EGR to operate it powers the electric drive to open the EGR flap so now dirty exhaust from after the DPF begins to flow in to the turbo inlet pipe, lets guess at half way of motor drive that the ballrace follower in the cam plate is doing nothing to the butterfly which remains fully open.
.
At say just over half way of motor drive the ballrace begins it climb up the cam profile and begins to close off the infeed air from the air filter so now the air to the turbo is a mix of dirty exhaust and clean air. on a fault free engine the electric motor drives out and back to make a controlled mix of air.
.
With the electric motor drive fully 'on', the EGR flap is fully open to dirty exhaust and the Butterfly is fully closed to the air filter so our engine is breathing 100% dirty exhaust air.
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BUT if the EGR cooler is soot blocked with the LP EGR fully driven the engine has no air supply to the turbo - its totally strangled!!!!
.
Use of Multiecuscan (MES) can show you the LP EGR opening command and on a good engine you can see it varying the drive to make an air mix. on an engine with blocked cooler the LP EGR goes to full open (say 4.7) or full closed (say zero) with no fluctuating mixing going on.
.
Blocked Cooler = strangled engine including limp mode.

 

[theoneandonly]

A few observations
its regarded as not good to idle these engines for too long before setting off and warm up on the move.
T9,T3 shows only 1 oil change no regen after oil change

Odometer at last Oil change 15534.5​

Distance from last DPF regeneration 2​

Average distance between last regenerations 760​

These values do not add up ave distance is also a lot.
The diffential pressure and clogging values are low supporting a recent regen
File 2 the frst T4 shows we have just missed a regen 2.2 ago.

Here we have low lpegr temperature because the engine temperature has not got upto working temp. The period is to short to say valve is or is not working normaly.
I can only recomend clear codes and do a good run get upto temp 10mins then 15mins run. template 4
Then we can be certain you have a blocked LPEGR and iffy injectors.

 

[jansla]

@Fredastaire so ecu knows/reads the opening of lpegr from this electric step motor’s position as there are no visiblle sensors. If this is a case what happens if the reduction gear is eliminated?

 

[theoneandonly]

@Fredastaire is there an hall sensor in the lid?

 

[Fredastaire]

Readers may appreciate that @theoneandonly and myself talk away from the forum. He knows my investigations and thoughts.i actually bought an EGR from ebay with a thought of installing in fresh air under the bonnet and plugging it in
I took the cover off for a nosey, alas it had been stored with water inside, the motor pinion heavily corroded. That set me looking further at the function. If you look inside the plastic gear of EGR flap there is a metal ring moulded in. It's not circular, in fact it's cam profiled. In the lid moulded in is a hall sensor, it must measure the air gap and thus give the positional feedback to the ECU. You can't therefore remove the reduction gear HOWEVER my idea is to remove the metal cam plate and replace it with a new one that just has a radial slot such that the butterfly stays open flat. The camplate is needed for the ballrace follower to keep the butterfly static otherwise it could oscillate.
.
The big problem is I can't yet see a way of reaching the LP EGR without dropping the subframe/ suspension and removing the DPF.
.
So thoughts still ongoing....

 

[BoultsG]

A few observations
its regarded as not good to idle these engines for too long before setting off and warm up on the move.
T9,T3 shows only 1 oil change no regen after oil change

Odometer at last Oil change 15534.5​

Distance from last DPF regeneration 2​

Average distance between last regenerations 760​

These values do not add up ave distance is also a lot.
The diffential pressure and clogging values are low supporting a recent regen
File 2 the frst T4 shows we have just missed a regen 2.2 ago.
View attachment 431124
Here we have low lpegr temperature because the engine temperature has not got upto working temp. The period is to short to say valve is or is not working normaly.
I can only recomend clear codes and do a good run get upto temp 10mins then 15mins run. template 4
Then we can be certain you have a blocked LPEGR and iffy injectors.

Thanks @theoneandonly, re the oil change; the one carried out at 15534.5 would be our first and only Fiat service (not a good experience). Following, I carried out an oil change, air filter etc.. at 30k & 40k prior to heading to Europe.

I will run the recommendation tomorrow.

 

[theoneandonly]

@BoultsG

Thanks @theoneandonly, re the oil change; the one carried out at 15534.5 would be our first and only Fiat service (not a good experience). Following, I carried out an oil change, air filter etc.. at 30k & 40k prior to heading to Europe.

I will run the recommendation tomorrow.

Now you have Mes you can reset the service and oil degradation software. If you don't the software can put you into limp mode demanding an oil change.

 

[theGman]

Today I spoke with the workshop manager about the way ahead with my engine. He said there "might" be a problem with air flow and that's why I get error codes and limp mode. Looking at the picture of the egr above would it be possible for metal particles to block this device? Considering there was substantial damage to my piston, valves and cylinder they used the original egr on my new engine.

 

[Poachersmoon]

@Fredastaire - not sure if can reach I haven't looked yet. Will on the weekend.

However even if you have to drop subframe.

What if the connection for lpegr to exhaust was blanked and a new pipe created to pull straight fresh air with a filter? That way it's not taking the exhaust gases from a damaged dpf causing the egr cooler block?

Could be interesting concept. Unless it's been brought up before.

I still want to try disable the fault codes in the ecu and unplug the egrs. But still waiting for more info if it can be done correctly.
You can also use a tuning box like superchips and swap to stock tune when you have the emmisions test