Technical Ducato Electrical Problems

[FiatDucatoCamperUK]

It's an ongoing issue. A mechanic temporarily fixed it for me 3 months ago, but didn't go into detail, just said it was a electronic issue and cleared some codes.

The van drove fine until last week, when the issue started happening again, and I don't know what triggered it (Perhaps the rainy weather?)

I've cleaned out the fuse/ relay box 2 days ago, took it apart, checked all the fuses, and there was some minor water stains/ dirt on the boards. I've cleaned out the connectors to the fuse box and tested the relays / fuses. Charged up battery as well.

I've also changed the grounding copper wire under the hood, and I get the same volt under the hood, as is on the battery.

The van worked, started as normal today morning, no issues, but after driving about 10 miles, the windshield washer came on, airbag issue icon and no electronics worked as well (indicators/ windows etc) . I went back home, as I suspected the engine won't start after it's off.

You can see the aftermath in the video. I started recording as soon as I plugged in the battery. ( I can only make the washer + headlights turn off by unplugging it).

Any advice is greatly appreciated.

ps. My Autocentre said it must be something to do with BCU and ECU, so they suggest replacing both before trying anything else, but I think they are just taking the easy way out, and quite frankly I can't afford spending £1k+ on a BCM/ ECM just to "see if it helps.

The other problem is that when I went for a test, no codes showed up as the car was working fine, but an hour later, this happens whilst driving...

 

[Anthony489]

Hi

I will do what I can from my armchair !

First off - as it's a camper there is always the risk that with the vehicle battery disconnected, the leisure battery can power up some of the vehicle electrics. It shouldn't of course, but odd things can happen so it's best to disconnect one side of the leisure battery whilst you are investigating things.

I am 99% certain from the symptoms that the BCM and ECU are blameless, I would want to eliminate a lot more things before splashing out on new ones.

The engine/gearbox to body grounding strap is vital, it takes all the starter motor current from the starter motor to the body. The current then flows through a separate thick link cable (in the battery box) from body to battery negative. If the strap goes high resistance you will have sluggish starter speed, and any electrical components that ground to the engine block (e.g. glow plugs) may misbehave. One check is to measure the voltage between engine block and body whilst the starter is being operated - there should be significantly less that 1 volt drop. I don't think this is likely to be your problem but its a good thing to eliminate it. A new thick braided strap and well cleaned mounting points are needed. BTW just measuring the battery voltage under the hood under light load is not a very sensitive test.

The items playing up (washers, windows, indicators) are all controlled by the Body Control Module (BCM). The BCM is mounted immediately behind the under-dash fuseboard, and mates directly to it via a multiway plug and socket. When you get multiple failures/oddities you have to look for something in common to all of them. I'd start by making sure the main 12 volt supply at the BCM is all OK. Check Fuse F38 in the under-dash fuseboard (B002). By the same token, the BCM must have a solid ground connection. Fiat ground wires are normally Black (Coded N for Nero on diagrams), and the BCM grounds to a lug on the body behind the centre of the dashboard (C022 Centre Dash Earth). I have a feeling this is hidden up behind the radio, just to be awkward.

I assume the fuse/relay board you attended to is the under-hood one (B001), as that's the one that is subjected to regular cold showers. Any visible signs of damp or corrosion are bad news if not sorted quickly. Lingering damp allows tiny leakage currents to flow even when the van is parked up (some connections stay live) and these cause metal connections to corrode and go black or even part company. If you can, it would be good to take a look at the underside of the board as well as the top. A clean up with contact cleaner/lubricant and an old toothbrush is often effective, and the light lubricant left behind helps disperse moisture.

It's hard to tell what skill level posters have, so I'm not going to launch into a long tutorial but I recommend when using a test voltmeter that you connect its black/negative lead direct to battery negative, (if necessary via some thin extension wire) and keep it connected there for all tests. The red/positive lead can then be used to check various voltages all referenced to the same point

One other thing to be aware of is that Fiat have a fondness for hiding wire junctions within the looms, so for example you may find three ground wires entering the loom and only one coming out. I recommend you check out all looms for chafing.

I attach an example schematic from eLearn showing the BCM and the wipers and washers. B001 is the under-hood fusebox and B002 is the under-dash fusebox.

 

[the green vanper]

Hello,

Known problem on the x250s.

Water ingress into the engine bay The water flows down the windshield, the plastic element (number 1 and 2) which should help evacuate water is too weak / don't fit perfectly the windscreen.

The clips that hold the plastic element can be bought from Fiat or other shops, they are quite cheap so it's worth to replace them. The part number is 71737918.

The two halves of the plastic element detach easily one from the other, I've read / saw that people glue it together, which also insulates from water. As far as I remember, there is a rubber part on the bottom, some kind of joint. It needs cleaning. Same as the bottom of the windshield.

As far as I remember, there are 2 hoses that evacuate water, they need regular cleaning.

In the engine bay itself, there are two types of engine cover, a plastic one, which is better. Looks like this:

and another one, made from some kind of paper, which tends to brake and bend. Pity, but also around the plastic one water gets onto the engine. It rusts around the injectors and makes them hard to remove (and / or glow plugs, can't remember, I don't own a diesel, in my van it gets around the spark plugs and causes misfire).

Another problem is water getting in the power steering fluid reservoir through the cap, or precisely through its venthole. Citroen and Peugeot were adding some kind of extra cover on top. Then SEVEL made then a new version of the cap. There are photos of it + numbers in one of the threads here. Can't find it right now.

And the most important: water gests onto the looms and then into them, into the ECU, sometimes also into the BCM. It causes rust, shorts, etc.

The earth points, especially those behind the headlight tend to rust. The earth cables rot in the inside.

All of the above mentionned cause strange electrical issues.

Here's a list and location of the earth points to check:

 

[Haywireuk]

View attachment 452788

It's an ongoing issue. A mechanic temporarily fixed it for me 3 months ago, but didn't go into detail, just said it was a electronic issue and cleared some codes.

The van drove fine until last week, when the issue started happening again, and I don't know what triggered it (Perhaps the rainy weather?)

I've cleaned out the fuse/ relay box 2 days ago, took it apart, checked all the fuses, and there was some minor water stains/ dirt on the boards. I've cleaned out the connectors to the fuse box and tested the relays / fuses. Charged up battery as well.

I've also changed the grounding copper wire under the hood, and I get the same volt under the hood, as is on the battery.

The van worked, started as normal today morning, no issues, but after driving about 10 miles, the windshield washer came on, airbag issue icon and no electronics worked as well (indicators/ windows etc) . I went back home, as I suspected the engine won't start after it's off.

You can see the aftermath in the video. I started recording as soon as I plugged in the battery. ( I can only make the washer + headlights turn off by unplugging it).

Any advice is greatly appreciated.

ps. My Autocentre said it must be something to do with BCU and ECU, so they suggest replacing both before trying anything else, but I think they are just taking the easy way out, and quite frankly I can't afford spending £1k+ on a BCM/ ECM just to "see if it helps.

The other problem is that when I went for a test, no codes showed up as the car was working fine, but an hour later, this happens whilst driving...

Hi, just wondering if you ever got to the bottom of these issues as we are having similar but slightly different issues with our 2011 Ducato. I’ve just posted our issues and am hopeful that someone can help