Technical Ghost problems (?) help needed for Fiat Ducato 115 multijet 2012

[Poelie]

Dear fiat owners,

A newby here, not ready to part with het Fiat Ducato 2012 115 multijet 2.0 liter engine self built camper van, but at the point of going nuts.

I’ve been having problems with my car since the moment I have bought it, 2 years ago. The engine light has come on more times than I can count with several different diagnostic issues. At one point I had to replace the entire engine, because it blew up. You’d imagine that would solve the issues, but instead we keep on getting (sometimes faulty) diagnostics. For example an EGR issue, when the EGR has just been replaced. The ECU has already been checked, and was in good order, the ECU plug has been replaced and the wiring to the ECU has been redone. Everytime we bring it to the workshop with an issue, it gets fixed. We drive for one or more short trips, and the engine light comes on.

The most recent example is that the oxygen sensor had to be replaced. I think this was a legit issue, but now it has been replaced and the mechanic drove with it for 30 miles without probleem. I started the car twice and the second time the light comes on again. I returned it, the fault code is ‘oxygen sensor’. He reset the error and I drove away again, but after switching the car of and on the check engine light comes on again.

This is just exemplary, but what makes it hard is that it sometimes seem to be genuine issues and other times the ECU seems to be too sensitive or generating codes that are incorrect. So I never know when to ignore the lights. I also would rather not have them, because I am not insured when driving with warning lights on the dashboard.

I have invested so much money by now, that it makes no sense to sell the car and it feels like we must almost ‘be fixed’, but at the same time I’m starting to doubt if we can ever fix it no matter how much time and money we spend on it.

I’d appreciate your input on the following two questions;

Does anyone know what could be wrong?

Reading this story, would you continue or give up / sell for parts?

 

[the green vanper]

Hello and welcome,

Looks to me like strange behaviour caused by water leak from under the scuttle tray.

Have you checked the connectors of the ECU? The wiring looms in the engine bay? Ground points, especially the one by the left hand side headlight?

It's a common problem in the x250, has been slightly improved in the x290 model. There are numerous threads here and on every motorhome / campervan forum.

Search with keywords on the forum, you'll find several threads.

The earth cables tend to rot in the inside, it's difficult to see. Replace the main ones (battery to body + body to gearbox) with a good quality copper wire. I'm buying them from a welding hardware store. They sell it by the meter and can add proper terminals at both ends.

 

[AsdaPricey]

Hello @Poelie

I’m going to echo checking the earth paths - the voltage drop and disruption caused by poor earths causes so many issues.
An example I can give of this was in a 1999 Merc A160 I once ran - it was a semi-automatic robotised transmission. I lost 0.4 of a volt at the transmission actuator and it went into limp mode and wouldn’t change gear. The resolve was replacing a corroded earth lead and nothing else.

When I got my 2008 Ducato it too had running issues, random limp mode, airbag warning lights, slow turning over - I changed the braided under bonnet earth lead, added a 2nd under bonnet earth lead and a 2nd battery tray earth lead. This dramatically changed running issues….so if you haven’t already I’d urge you to do so as a starting point….don’t give up!!!

 

[Poelie]

This is super helpful, thank you both!

My mechanic did once check the earth lead and said all was fine but I might be doubting and get a second opinion. Especially after I replaced the ECU connector two weeks ago as it was corroded inside! Apparently some water did reach it indeed..

And thanks for the words of positivity! Will keep you posted of the second opinion

 

[the green vanper]

the ECU connector two weeks ago as it was corroded inside!

Ha!

Find the appropriate threads here to repair the scuttle tray.

You have to remove it, clean everything, buy new plastic clips that will keep it in place, find a solution to glue the middle joint of the scuttle tray (could be one of the sikaflexes or the glue used with vehicles' windshields/windows). Clean the ducts that are ment to evacuate water, check the engine cover (have you got any? the paper one? the plastic one? - the plastic one is the best, but not ideal), check if you have the extra plastic cover on the power steering fluid reservoir or the new type of the cap (with no vent hole).

Check the spaces around the injectors - water loves to stay there for a long period of time.

 

[Poelie]

Quick update in between. Scuttle tray and pipe seems good but noticed these rusty bolts and cables. Not too experienced so maybe you guys know what this is and whether it could have cause my issues?

Drivers side, below fuse box.

 

[AsdaPricey]

Quick update in between. Scuttle tray and pipe seems good but noticed these rusty bolts and cables. Not too experienced so maybe you guys know what this is and whether it could have cause my issues?

Drivers side, below fuse box.

Picture 1 - your under bonnet earth braided cable. All connections need cleaning back to bright metal and preferably the cable changed to something sheathed and larger in cross section if possible.
The whole current path needs to be unobstructed in its flow around the circuit otherwise the voltage and current reduces - in another term it’s like your own heart if the arteries are blocked the blood supply to the heart is insufficient…it’s the same with vehicle electrical circuits.

So this element is one portion of a circuit. Clean this then see what improvements if any. If none then move onwards through the wiring checking for corrosion at the fuse box and ecu connections, breaks in cables for the under bonnet loom.
I cleaned every single connection in the fuse box and ecu connections- it was incredibly boring but very important. I wish I’d taken pictures of how dull and grey the fuse box connections were.