As you may of read from previous posts about the issues i have had since December regarding fault codes PO401 no engine light and PO402 limp mode Engine light activated
I was advised to take to Fiat for a software update which would resolve this issue and improve drivability this was carried but on inspection Fiat found the Engine oil was loaded with soot even though it had been recently serviced
Intercooler loaded with soot
Soot passing the DPF
Injectors Knackered
Fiat quoted between £6-£8k to fix the problem which i refused

Any way i embarked on fixing this my self with lots of help from whine0

First i removed Injectors and had them tested result completely destroyed so a Brand new set was purchased from a diesel specialist and friend £560 + vat (mates rates)
whilst these were away being tested stripped out the intake system intercooler and EGR valve and pipe work and cleaned as heavily contaminated with soot and carbon build up also changed the EGR valve this was purchased from coastal motorhomes £119 +vat also changed the MAP sensor as this had a big ball of carbon fouling it all put back together and not much improvement some days it would run spot on the next limp mode PO402 air intake meter faulty and PO401 high pressure EGR blocked with no engine light this fault also stopped the DPF regenerating stopped EGR airflow monitoring and the EGR exclusion valve from working
I found out that if i disconnected the MAF sensor that i would not get any more PO402 fault/Limp mode and it drove loads better better MPG and power but still the PO401 fault code
I presumed the MAF sensor was at fault but soon found out that disconnecting the MAF puts the fueling into OPEN circuit mode a default setting in the ECU which will keep the vehicle operating if the MAF fails this OPEN circuit is also used on wide open throttle acceleration..and closed loop when driving normally fuel trim adjusted by O2 sensor and MAF The reason why i thought the MAF sensor is because of the PO402 fault and miss matched Desired air flow readings (causing fuel trim to be rich and O2 sensor trying to lean it off) from live data i collected on Multiscan so ordered a new one from Coastal motorhomes £161+vat that was replaced this week which seemed to make an improvement no PO402 fault/Limp mode for the few days i drove it but still the PO401 high pressure EGR blocked by this time i knew when this fault had been stored but not put the check engine light on as the Instant consumption was all over the place irractic power and pinking knocking sound from the engine also surging at a steady throttle like being pushed from behind this sensation was seen on live data which show the fuel trim on the injectors going wild this when the pinking knocking sound happened the Fuel usage dropped considerably as soon as the the injector fuel trim came back to a normal level this when i got the feeling of being pushed up the backside them the Fuel usage shot up from 16mpg to 40mpg ( so that ruled the MAF out)
I had complained about this surging to fiat from when i bought it brand-new my thoughts are this is what caused the injectors to fail (possibly faulty EGR valve )
Yesterday we removed the EGR valve cooler this as now been moved to the back of the engine underneath the turbo to get access to it you have to remove the subframe steering rack and DPF the cooler as a fine gauze fitted internally which was covered with thick flap of soot/sticky carbon which was blocking restricting HIGH pressure egr gases not enough to cause a full PO401 fault but an intermittent fault so goes unseen but causes a lot of damage to the intake and exhaust system also injectors
I had purchased a new EGR cooler which i had to get from FIAT at £250+vat the replacement took 6hrs to do from start to finish
i then reset the injectors egr valve and maf sensors as if new and took for 100 mile test drive a mixture roads
Result all problems solved its running the best its ever done since new and averaged 36mpg on the test run ive never been able to get it above 29mpg whether loaded or unloaded driven carefully or thrashed before

Luckily i don't think the DPF as been damaged with the soot as its now doing regens normally and showing NOT GLOGGED and the last timed i looked this morning it was at 20% soot loading only thing left to do is get the O2 sensors checked to see if they are reading correctly as they could be contaminated with the high soot loading if faulty this also affect the Injector fuel trim settings

Hopefully i can get back to earning and not spending it all

hope this info is of use to anyone

I have manage to clean the blocked EGR cooler soaked it over night with carb and brake cleaner then power washed out *the gauze filter is strong enough to with stand pressure washer* then filled with concentrated acid wheel cleaner and left to soak for a few hours and again pressure washed through from both ends its now clear of any soot carbon blockages and currently drying on the radiator before being packed away as a spare also if your going to do this you will need a replacement O ring for one of the water cooler pipe that fits into the engine block

part number 5801920151 £11.45+vat

Info for removal supplied by whine0

Egr cooler removal


Remove neg battery
Straight up in air now get oil tub with funnel disconnect power steering pipe above lower right engine cover while that drains lower ramp remove dpf wires near vacuum reservoir
Remove 2 dpf vac pipes
Steering straight remove 13mm pinch bolt cab floor for rack remove uj off rack
Remove cab floor grommet over rack spline
There’s a 10mm to right dpf bracket back of head
There’s a 13 mm to left dpf bracket what all wiring join too
Next remove 16mm nut and clamp join dpf filter to turbo , the clamp open and extend over turbo or dpf
Next crack bolt top off power steering pump remove bolt and pipe
Lower engine covers remove
Front wheels off bottom ball joint and track rod bolts removed
Van in air mark sub frame with paint drop 6 subframe bolts lower mounting off then drop subframe with rack if you push engine forward you can pull dpf without disturbing alternator
Now off with dpf filter pull out bottom but watch that dpf bracket catching alternator it catches Exciter wire plug remove dpf mounting then egr cooler ready for removal
Don’t touch radiator bottom hose just remove coolant pipe off egr cooler to drain engine coolant have big bucket to collect water now cooler can be removed

You have certainly had your share of issues. Hope it stays OK now.
One question - I don't understand how the intercooler could get clogged with soot. All issues with soot should be downstream from the egr entry point, I would have thought. How could any soot go upstream?

Ian.

Think the exhaust DPF and EGR valve system and inlet manifold was so restricted with the soot build up may be back pressure other than that I have no idea the pipe from the turbo to intercooler wasn’t to bad it was from intercooler to throttle valve
It’s been a nightmare but hopefully all issues have resolved

Well thought we had fix it no more EGR faults but very poor drivability lack of power poor fuel economy and still the Hesitation and Surging on a constant throttle (complained to fiat about this since it was 6 months old) this was accompanied with very noisy injectors even though they were brand new
The only think that i had not changed that can make changes to the injector fuel trims was the Pre cat Lambda sensor

After hours of live data i noticed there was not change in the O2 reading always between 16-17% so i decided to remove and inspect it it was quiet dirty with soot and carbon deposits in the small slots so i cleaned out with a small piece of wire and replaced resulting in better drivability MPG slightly improved and lower )2 readings which resulted in less noise from the injectors

I purchased a new Lambda sensor FIAT ONLY part after trying various motor factors FIAT part 55281073 £126
Fitted it and reset as new in Multiscan the difference was night and day very smooth acceleration plenty of power no more hesitation or surging and an increase from 28mpg to 33mpg over 1500 miles of driving and a super quiet engine O2 readings down to 5-6% at a constant throttle 65mph and a smooth voltage trace on live data

Cant understand why this would not have logged a fault code looks like this could of been the root cause for all of the issues i have had

Bad O2 sensor causing injectors to fail with crazy short term fuel trim which as caused then to over fuel hence the massive soot/carbon build up which damaged all the EGR components which produced fault code PO401 again no engine check light but stopped DPF from regenerating so more soot/carbon build up

thought i fixed the bloody thing but this morning started behaving strangely jerky throttle very poor acceleration at times so hooked up to Multiscan no Faults logged but the throttle was all over place so highlighted the gas pedal in parameters and operated the pedal and the percentage was all over place nothing from 0% to 10% then wildly over the place so disconnected it and cleaned the contacts and it works as it should...will find out tomorrow if that as sorted that out again no FAULT CODES logged which i find strange

Replacement from FIAT is £66+vat so fingers crossed this is the last

Wow - A brilliant description with one of the best research investigations I have read.
Was this finally solved?

I have a similar problem on a 3.0 HDi (2009) with EML on always, code fault is P0401 with engine hunting when on tickover and only 29mpg.
once MAF disconnected engine runs smoothly instantly and mpg goes up to 36mpg and vehicle runs brilliantly.

Now after reading your problem will see if Lamda sensor is the problem.

Only bought it in August and have done 3000 miles taking it to 100k only so would like to keep it going if I can.

Stanski said:

Wow - A brilliant description with one of the best research investigations I have read.
Was this finally solved?

I have a similar problem on a 3.0 HDi (2009) with EML on always, code fault is P0401 with engine hunting when on tickover and only 29mpg.
once MAF disconnected engine runs smoothly instantly and mpg goes up to 36mpg and vehicle runs brilliantly.

Now after reading your problem will see if Lamda sensor is the problem.

Only bought it in August and have done 3000 miles taking it to 100k only so would like to keep it going if I can.

Click to expand...

First try a new maf sensor if you can find one at a reasonable price

All sorted it was a ecu software problem that stopped the dpf regenerating which fouled up the complete egr system caused thousands of ££££ of damage had to replace everything
New injectors EGR valve Map sensor EGR cooler DPF and all related sensors Differential pressure sensor also turbo as it warped the shaft due to the higher pressure Fiat quoted around £9k for the repairs managed to get the parts mostly from Coastal Motorhomes and other vendors and fitted at a local garage for £3500 multi scan £100 to update ECU parameters after replacing parts and £250 for Fiat to update the ecu software

no issues at all now other than the Oil dipstick broke at the bracket forcing nearly all the oil out in-between xmas and new year had to get a new one from Fiat was expecting £40 max but was £120 truly anal raped again

and no liabillity from the company that made the van at all,,,the cynic in me thinks that a bit of faulty software can create thousands in parts and service work for your dealer network.
i think you,ve been incredibly patient , a pending £9k bill (or even £3,5K) would make a van unworkable for me especially with the months of messing about,well done for perservering

I had the Hunting at tick over on my old 2007 ducato it turned out to be the vacuum hose for the EGR valve had split and the EGR valve was heavily fouled with carbon replaced the EGR valve and Turbo Boost relay valve at the same time which fixed that problem but eventually had a remap done with an EGR valve delete never looked back after that

Stanski said:

Wow - A brilliant description with one of the best research investigations I have read.
Was this finally solved?

I have a similar problem on a 3.0 HDi (2009) with EML on always, code fault is P0401 with engine hunting when on tickover and only 29mpg.
once MAF disconnected engine runs smoothly instantly and mpg goes up to 36mpg and vehicle runs brilliantly.

Now after reading your problem will see if Lamda sensor is the problem.

Only bought it in August and have done 3000 miles taking it to 100k only so would like to keep it going if I can.

Click to expand...

I had the Hunting at tick over on my old 2007 ducato it turned out to be the vacuum hose for the EGR valve had split and the EGR valve was heavily fouled with carbon replaced the EGR valve and Turbo Boost relay valve at the same time which fixed that problem but eventually had a remap done with an EGR valve delete never looked back after that

Hi PC Vehicle Movements,
Slow in getting on top of this problem I am but am confident that I only have one issue now after cleaning MAF and Lamda Sensor.
Turbo Boost Sensor - Code P0235 is the only one to resolve it seems.
With all your records do you have a part number for it please - the one I have on mine is an italian made one but the number is not easy to read.
After doing some research I was expecting a Bosch item - so was flummuxed when I got this out.
Any help would be welcome - Many thanks

Hi Stanski

The boost pressure sensor is a relatively simple cheap part (about £30), so I suggest you change it and see if the fault clears.

I believe the Fiat part number is 55219298, and many different makers can supply parts that conform to that specification. No doubt Fiat fitted whoever was giving the best price at the time, and the part on your engine may have the maker's part number, the Fiat part number or possibly both.


Please don't take my word for it, double check with a dealer for the Fiat part number (based on your vehicle VIN), then search for that number on supplier's websites e.g. buycarparts.

@PC Vehicle Movements
Thank you for documenting your trials and tribulations in so much depth.
I also have a 2017 Ducato, so far no problems (only 8000 miles)
you mention a specific ECU update (mine was updated 2019 on its first service) is this visible with Multiecuscan? if so how obtained?
You also mention live monitoring what specific parameters (screenshot would be handy) i cant see anything related to trim values.
Thanks
john

Good morning

Everything I did to fix the issues are in the post
I would check your exhaust and if there is any sign of soot deposits in the tip I’m afraid your DPF is damaged
The EGR cooler will be blocked-restricted flow due to a build up of soot and gunge on the fine mesh gauze
I managed to clean mine once removed by soaking over night filled up with an acid wheel cleaner and then power washed clean
DPF pressure sensor was replaced
The injectors were beyond repair and needed replacement with brand new ones
The turbo was replaced as the pressure build up due to DPF being blocked warped the shaft even though MES was showing DPF to be ok
Also to the right of the throttle body there is a mixing chamber we’re the EGR gases are introduced there is a small pipe with ball at the end with small holes in this was completely blocked with a tar like substance this also gets into your intercooler
I also changed all of the temp sensors and both lamba sensors when we fitted the new DPF

I have sold the Ducato now but it’s had no issues at all since the work done other than the Turbo boost pressure selonoid needing replacement every 30k miles or so they just get worn out and become slow at reacting to demands

Hi, am I right in understanding that the root cause of all your problems (about which you have my sympathy) was it needed a software update? This is what I’m being told by Fiat will solve my similar problem - once I’ve had the injectors, DPF, EGR valves & intercooler replaced!
I’m going to have to decide whether I can trust my Ducato camper or replace it, only done 15k miles but out of warranty.
Cheers, Baz

@PC Vehicle Movements , we conversed last december, (thanks for that). Ive changed my MAP and the Turbo solenoid in December and not had MIL light or Limp Mode since. [Ive also lost hesitations and more power now; I wasnt aware that I had hesitation / power loss before I changed these parts], a hand held FCR shows nothing. HOWEVER MES does show P0401 - 61 as intermittent, I clear this and then it re-appears another day after hours of running. The recorded event which triggers that P0401 shows the EGR's and pressure all working to instruction yet the airflow actual is generally 1/4 of requested. Normal running with MES connected and watching live data shows all airflows and pressures and EGR's to be following commands. My only guess is that foot hard down on a hill accelerating that the LP EGR cooler might be partially or completely blocked and with the engine being short of EGR air that the turbo cant catch up quick enough - thats my thought. Have you any comments that may help? Im well aware of the tedious hours to change the cooler and its probably beyond common sense at my age to attempt it at home on ramps and working flat on ones back. copy for @Baz in Kent @theoneandonly

Baz in Kent said:

Hi, am I right in understanding that the root cause of all your problems (about which you have my sympathy) was it needed a software update? This is what I’m being told by Fiat will solve my similar problem - once I’ve had the injectors, DPF, EGR valves & intercooler replaced!
I’m going to have to decide whether I can trust my Ducato camper or replace it, only done 15k miles but out of warranty.
Cheers, Baz

Click to expand...

As far as I’m aware yes the update will resolve the issues but if it’s gone un noticed like mine the damage may all ready be done

Fredastaire said:

@PC Vehicle Movements , we conversed last december, (thanks for that). Ive changed my MAP and the Turbo solenoid in December and not had MIL light or Limp Mode since. [Ive also lost hesitations and more power now; I wasnt aware that I had hesitation / power loss before I changed these parts], a hand held FCR shows nothing. HOWEVER MES does show P0401 - 61 as intermittent, I clear this and then it re-appears another day after hours of running. The recorded event which triggers that P0401 shows the EGR's and pressure all working to instruction yet the airflow actual is generally 1/4 of requested. Normal running with MES connected and watching live data shows all airflows and pressures and EGR's to be following commands. My only guess is that foot hard down on a hill accelerating that the LP EGR cooler might be partially or completely blocked and with the engine being short of EGR air that the turbo cant catch up quick enough - thats my thought. Have you any comments that may help? Im well aware of the tedious hours to change the cooler and its probably beyond common sense at my age to attempt it at home on ramps and working flat on ones back. copy for @Baz in Kent @theoneandonly

Click to expand...

Possibly the EGR cooler filter gauze partially blocked restricted
But I did change the DPF differential pressure sensor and that made a massive difference