Hi I have a 2001 Doblo Cargo, it has got a weird issue where if the battery is disconnected for a while it'll start and everything works fine. Then all of a sudden all of the dials drop and the indicators etc stop working. And if you turn the engine off you can't restart it so you have to disconnect the battery. It lasts about 4 mins of everything working and then nothing for ages. I'll attach a video so you can see what happens when everything fails. Any help would be appreciated

Lots of Fiats suffer with the main battery cables corroding internally. Each end looks fine, but the internal resistance is too high. This can give all sorts of weird electrical issues, often the electric steering will play up first.

Yours could be failing as it gets warm. Disconnecting and reconnecting will flex it to make a connection, then as it warms up due to the high internal resistance it lets go.
If possible, put a jump lead from battery to engine to 'test' the earth cable.

Might also be a good idea to check all earth connections too, especially from instrument panel. Some models suffer from water in the fuse box, so that could be checked.

Hi

Yes earth cable would be prime suspect..

There is a testing guide here:

https://www.fiatforum.com/grande-punto/318839-electrical-gremlin-thread.html



Charlie

Thanks for the replies, I have tried the jump lead to the engine and it didn't seem to work. But might be a problem with my jump leads as they're quite rusty.
I'll try and trace it further as, also might try a clean pair of jump leads.
It's just annoying as everything stops working after about 4 mins of it working

So does the engine turn on the starter..?

If it spins over.. but not fire and run.. thats different

Oh yeah it turns over but it's sort of immobilised, until you disconnect the battery and reconnect and then sometimes it starts.
It's reading the key fine but just all the electrics go weird, but when it does start everything runs fine for about 4 minutes.


The engine, lights etc work fine and it runs fine for about 4 mins

Ive made a video showing what happens when its running normally, you can hear the fan is on, the hazards are on and the lights are on. Fuel gauge is registering and the speedo needle is sat on 0, but when it goes hazards stop working, I turn the fan off, and all the needles drop and it doesn't register anything.
As you can see it was running for 4 mins from when I connected the battery before it died.
After that is the clip of trying to start it when its gone weird, you can hear it turns over, but nothing is registering, the hazards or indicators don't work as well. And the radio normally works fine but when the fault occurs it just displays "CANCHECK"

youtu.be/BcjbziEuXnE

ryannobson said:

Oh yeah it turns over but it's sort of immobilised, until you disconnect the battery and reconnect and then sometimes it starts.
It's reading the key fine but just all the electrics go weird, but when it does start everything runs fine for about 4 minutes.


The engine, lights etc work fine and it runs fine for about 4 mins

Click to expand...

Hi
If it spins on the starter.. it 'suggests' the earth cable is passing enough current..

BUT.. youve definitely got a fairly major electrical issue

It might help to give us a little background..

Had it years.. trouble free..??

Blown any fuses..?

Had a clutch last week ?? Etc..

There is often a disturbance.. or pattern of minor niggles before a failure...
Start here :

https://www.fiatforum.com/grande-punto/318839-electrical-gremlin-thread.html

The fundamentals are the same for your van..
A lot of the design will be almost identical

Its the '4 minute rule' thats getting me


Something is probably getting HOT..

But those tests should help a lot

Multimeters start at @£5...

Could very soon pay for itself

Do let us know what you find

Unfortunately I don't know much to the background.
Had it since Friday and it ran fine for around an hour until all the electrics went on the way home, As the speedo went I turned it off and on to which it wouldn't start.
I thought it was out of fuel, RAC couldn't figure it out and no faults were showing, after being recovered at 10pm to a garage, I disconnected the battery and then the next morning it started.

But from all the searching I've done I cant find the solution, I don't really know the history of it at all which is a pain.

The "4 minute rule" Used to be an hour, but its slowly got less and less to the point of just being 4 minutes now sorry I should've mentioned that. I do have a multimeter somewhere I'll have to dig out

Could this be possibly caused by a dodgy battery or terminals, I don't know how good the battery is but the previous owner told me it had a issue holding charge, I haven't found this myself but wondering if a faulty battery could cause it, Or the connectors on the leads for the battery, One thing I have noticed but haven't thought could be the real cause is both connectors are so loose that they don't clamp onto the battery, even when fully tight you can just pull them straight off

Loose battery clamps

HEAT

Yes sounds like your issue



Quickest test..

Either borrow a different battery.. with fatter posts

Or

Get some copper plumbing tube

15mm ideally.. cut off 2 x 20mm wide sections

And slit it down 1 side ( 1 cut on each tube)

Slide 1 over each battery post..
Then fit clamps.. will tighten properly for a good connection now

So I got a brand new battery which seemed to sort the problem, but 10 minutes later, there it was again.

So I replaced the main earth wire to the gearbox, And put on a new clamp on the negative, No joy still.

Then I took the engine fuse box out, dismantled it and blew a warm hair dryer on it for about 20 mins. Then when putting back together I changed every micro blade fuse for a brand new one thinking maybe one had a dodgy connection or was faulty. But still no luck.

So finally I took off the positive lead that clamps to the fuse box and replaced that along with the main positive down to what I assume is the starter, Replaced it and the positive clamp, and still nothing has changed!

Im starting to think maybe the ECU but I don't understand why it works sometimes and then dies.
I've cleaned as many earth points as ive found which is about 3, and still no luck.

Just checking as well did you have a look at the link I put a few replies up to the video of what's happening?

Still so confused I've never known anything like this before, Does anyone know the locations of all the earths on the 2001 Doblo Cargo?

So the battery and cables have been ruled out.

The previous owner's description of a battery not holding charge might just be his assumption of the fault. He probably sold it becaus he couldn't fix it.

As Charlie says, something is getting hot. Something that has current to it when the engine is running.
ECU
Sensors
If it is a mechanical injection system, there should be a fuel cutoff solenoid on the injection pump. If common rail with electronic injectors, probably not.
Crank sensor
Any others?

Fuel pump.

Locate all of theseitems, and every other you can.
Run the engine until it goes silly.
Carefully test each sensor for heat, including their connections, as it could just be a connection not the sensor itself.
Might need to check the dashboard connections too, which might be a challenge.

Ideally it needs MES connected showing live data, to hopefully highlight the area that has given up.

How do I know if it's mechanical or common rail injection?
Also don't have anyone with access to MES, I have a MacBook so can't get it on there either. I do have a Bluetooth OBD reader which works pretty well for my VW but doesn't show any faults of any kind on the Doblo so unsure what to do. I'll find all the sensors and give them a feel for heat.
Thanks

portland_bill said:

So the battery and cables have been ruled out.

The previous owner's description of a battery not holding charge might just be his assumption of the fault. He probably sold it becaus he couldn't fix it.

As Charlie says, something is getting hot. Something that has current to it when the engine is running.
ECU
Sensors
If it is a mechanical injection system, there should be a fuel cutoff solenoid on the injection pump. If common rail with electronic injectors, probably not.
Crank sensor
Any others?

Fuel pump.

Locate all of theseitems, and every other you can.
Run the engine until it goes silly.
Carefully test each sensor for heat, including their connections, as it could just be a connection not the sensor itself.
Might need to check the dashboard connections too, which might be a challenge.

Ideally it needs MES connected showing live data, to hopefully highlight the area that has given up.

Click to expand...

Diesel engines inject the fuel at extremely high pressures.
Originally this was done with a mechanical pump creating the pressure for each individual cylinder. More recently technology has allowed electronic injectors to work with these high pressures, so we get a high pressure pump feeding a common 'rail' (a tube near the cylinder head with constant pressure). The injectors are all connected to and fed from this rail, and injection is fired electrically.
Common rail may have an engine driven high pressure pump, or some now have the high pressure created by the pump at the tank, but this creates the risk of leaks along the length of the vehicle.

Start at the cylinder head. Wach injector has a feed pipe. Follow these back. If they all arrive at a single tube, it is 'common rail'. If they all go back to the pump, with individual connections, this is mechanical.
From the common rail, follow its feed, it will probably go to a pump mounted on the engine.
Look at either pump to locate every electrical connection, any could be a possible failure point. Check every connection is secure.
A mechanical pump should have a solenoid on it, usually at the opposite end to the outlet pipes. This cuts off the fuel supply when the ignition is turned off. Usually when they fail, they shut, so cutting off the fuel.
On some the solenoid can be removed, then inside is a plunger that can be removed and the solenoid replaced. This will allow the engine to run, but stopping it would require a deliberate stall as turning off the ignition will have no effect. Don't lose the plunger, as it may not come with a new solenoid, and when replacing it, it must be scrupulously clean. The pump and injectors are high precision items and any particles may damage them.

A simple thought, have you checked the fuel filter? These are designed to separate water from the fuel, but as a result need draining occasionally. There will be a drain tap on the bottom, often a large thumbwheel. Put a rag or container under it and open the tap. Close it when you get just clean fuel.
Fuel will rise to sit on top of water. If the filter is overfull, initial startup may be possible, but as the fuel flows, it collects the water until it pushes enough in to stop the engine.
This will not cause any electrical issues, so is not your problem, but worth checking anyway.

The pump at or in the tank pushes low pressure fuel forward to the high pressure pump at the engine. If that pump fails, it all stops. Again this shouldn't cause the electrical issues you see, but worth checking that the pump runs at time of failure.

Hi, Thanks for that.
Im pretty sure from your description its common rail but i am going to have a look in just a second.
Ill try and check as many connections as I can find to see if I can find the solution.


Just as a side note. I found this little earth box last night that has snapped off its original mount, and someone had previously put a wire in it to the negative terminal, so I replaced the wire and mounted to the battery and then tried on frame but it made no difference, unless the wire it needs has to be bigger etc so any advice on that would be great

I've fixed it!

So it turns out after reading a post about someone having a problem with their radio immobilising their Doblo and when they removed it, everything worked fine, I took the radio out this morning and have had no issue since!

Anyone know why the radio would've caused this?

Genuine radio..?

What brand..??

Well done for solving the mystery.

If it is not the genuine radio, it could be interfering with the CanBUS signals.

Prior to CanBUS, the radio had an 8-pin power plug, not all terminals of which were used. As well as permanent 12v and earth, there would be an ignition 12v, and could be any or all of these. Lights on, speed signal, reverse signal, output to aerial, telephone mute.
With CanBUS, there is normally just a permanent 12v and earth, plus the two CanBUS signal wires, although still using the standard 8-pin plug.
Any aftermarket radio needs isloating from the CanBUS, properly with an adapter that interprets the digital CanBUS signals and presents the radio with an analogue signal at the appropriate terminal. Alternatively, a separate ignition feed can be supplied, as long as the CanBUS wires are disconnected from the radio.

If an aftermarket radio has been fitted, and just plugged in, that can disturb the CanBUS which may be what you are experiencing. The car plug contains the 12v and earth, the other two tiny wires can be removed, insulated and taped away. The radio will then be permanently live, so a switched feed maybe from the cigar lighter would be a good idea. Or better, a proper adapter.

If it is the original radio, I suppose it is possible for an internal fault to send silly signals along the data wires. An original radio would be coded to the car, so will communicate along the data wires, perhaps erroneously.

If an original radio, bin it and fit an aftermarket, with properly sorted connections.
If an aftermarket, sort the connections.

Yeah was a genuine original radio with tape deck.

I will have a look at fitting a spare aftermarket radio I have paying around but if that fails I'll just hard wire in a bluetooth speaker to charge on the cigar lighter and poke it out the way somewhere.

I have driven the van around today now for probably a total of 6 hours with no faults or signs of anything not working!

Im so shocked that it was such a simple thing considering I spent £110 yesterday on the battery and a load of replacement cables and none of it even made a difference lol.

But tomorrow I will look into the aftermarket radio and see what I can do

Good to hear its behaving now

I didnt recognise that wired block you found.. the radio issue and it might be related..

Anyway.. putting a different cd unit in there
Will soon prove or disprove..

Charlie