Technical 2015 Ducato 180 Multijet 3.0 L Very strange set of events

[Tallykissangel]

Hi everyone. Our Ducato motor-home hasn't been starting for a few weeks now.
Just coming up to 6 years old. 190 klm on the clock.
We've been told its injectors, starter motor, earth leads, sensors.
It all started when I had a flat battery and it wouldn't turn over enough to start even with battery charged.
I replaced the battery with a good AGM battery.
It turned over fine but still wouldn't start.
I disconnected the battery...left it off overnight...still no go.
Then I read in this forum about the fuel cutoff switch.
I tried that and it stated.
Problem solved??
No.
A few days later it played up again.
I suspected electrical but after using 'Start Ya Bastard' (yes that trade name here in Oz) it started and ran fine for a few days.

Then it started doing the same thing again.
Eventually even 'start ya bastard' wouldn't get it going.

I was told it was blocked injectors reducing rail pressure.
They tried to get one injector out but stopped when the slide hammer couldn't budge it at all.
Thank goodness.
It started that time with 'start ya bastard' and got us home but then ...yep...stopped again.

Then.... after 4 weeks sitting idle i went out today to disconnect the battery and drain the ECU.
I had done this before a few times.

Imagine my surprise when the battery was disconnected all the dash lights, fuel transfer pump etc all came on. No battery !!
I then decided to try and turn it over since everything was lit up like a Xmas Tree.
Starter turned over over 2 times and then a large BUSS (mann?) fuse 150A 58C 28814 located on the top of the positive terminal blew.
I could see the flash.

Naturally I was curious since MHome the battery was not connected but power was coming form somewhere. ? MHome house battery?

I then reconnected the battery to see what damage I'd done and of course tried to start the MHome and guess what....started first go.
Then started every time I tried after that. Even with the BUSS fuse blown.

So can I ask someone who knows what have I blown and what is the BUSS fuse for (I know it to protect something but what?) and how come the van is starting everytime now without that fuse?

Could it bee that the house battery was drawing off or interfering with starting.
I have the van connected to the mains when idle so the house battery is well over 13.7v
Also before today I had the van battery connected to trickle charge so it never ran down.

Help please...........not that I'm disappointed with the van starting now but need to know how urgent it is to replace that fuse.
Many many thanks

John

Victoria
Australia

 

[bugsymike]

Hi everyone. Our Ducato motor-home hasn't been starting for a few weeks now.
Just coming up to 6 years old. 190 klm on the clock.
We've been told its injectors, starter motor, earth leads, sensors.
It all started when I had a flat battery and it wouldn't turn over enough to start even with battery charged.
I replaced the battery with a good AGM battery.
It turned over fine but still wouldn't start.
I disconnected the battery...left it off overnight...still no go.
Then I read in this forum about the fuel cutoff switch.
I tried that and it stated.
Problem solved??
No.
A few days later it played up again.
I suspected electrical but after using 'Start Ya Bastard' (yes that trade name here in Oz) it started and ran fine for a few days.

Then it started doing the same thing again.
Eventually even 'start ya bastard' wouldn't get it going.

I was told it was blocked injectors reducing rail pressure.
They tried to get one injector out but stopped when the slide hammer couldn't budge it at all.
Thank goodness.
It started that time with 'start ya bastard' and got us home but then ...yep...stopped again.

Then.... after 4 weeks sitting idle i went out today to disconnect the battery and drain the ECU.
I had done this before a few times.

Imagine my surprise when the battery was disconnected all the dash lights, fuel transfer pump etc all came on. No battery !!
I then decided to try and turn it over since everything was lit up like a Xmas Tree.
Starter turned over over 2 times and then a large BUSS (mann?) fuse 150A 58C 28814 located on the top of the positive terminal blew.
I could see the flash.

Naturally I was curious since MHome the battery was not connected but power was coming form somewhere. ? MHome house battery?

I then reconnected the battery to see what damage I'd done and of course tried to start the MHome and guess what....started first go.
Then started every time I tried after that. Even with the BUSS fuse blown.

So can I ask someone who knows what have I blown and what is the BUSS fuse for (I know it to protect something but what?) and how come the van is starting everytime now without that fuse?

Could it bee that the house battery was drawing off or interfering with starting.
I have the van connected to the mains when idle so the house battery is well over 13.7v
Also before today I had the van battery connected to trickle charge so it never ran down.

Help please...........not that I'm disappointed with the van starting now but need to know how urgent it is to replace that fuse.
Many many thanks

JohnView attachment 410673
Victoria
Australia

Does sound like part of the problem may be the split circuit charging system for the Leisure battery, does it have an isolator switch so you can just work on Ducato side of problem first.
Maybe contact the camper/motorhome builder.
Then with a good fully charged engine battery any error codes in the system will need to be checked possibly with a Fiat Multiscan program , a lot of people on the Forum use it with success.
Love the name for "Easy Start Spray"

 

[Tallykissangel]

Does sound like part of the problem may be the split circuit charging system for the Leisure battery, does it have an isolator switch so you can just work on Ducato side of problem first.
Maybe contact the camper/motorhome builder.
Then with a good fully charged engine battery any error codes in the system will need to be checked possibly with a Fiat Multiscan program , a lot of people on the Forum use it with success.
Love the name for "Easy Start Spray"

Thank you very much Bugsy.
Yes my feeling is that its linked into the leisure battery to charge from alternator when driving.
But that means then that when cranking I'm drawing off both batteries?
I wonder the reason it wouldn't start was because the leisure battery also on its last legs and sucking cranking power form the new battery?
But again i had the leisure battery constantly charged form the mains plug.....but maybe its dying and not able to crank. looked good on the voltage meter but I never thought to check that as I was cranking to see if it dropped right off. Need two people to do that.

I will run the van today and see if the 'house' battery is charging with the fuse out and the mains off. That should tell me.
So the golden rule here would be 'change the main battery; change the leisure battery'?

I was psyching myself for injector removal, and most likely snapped, and thousands of dollars out of pocket. Up to $10000+
BUT I was prepared to first go through checking and swapping out the simplest to the most complex (injectors/glow plugs) to get it to start.
Just serendipity that made the fuse blow and the MHome to start.

I did notice when I put the Mutiecuscan on that the starter RPM was only about 170rpm even with a new battery.
That should have told me something but I thought 'replace the starter motor' and indeed had ordered one.

The only code that showed is the ubiquitous airbag light which has been like that for 2 years now with our lockdowns etc.
Im getting it reset/cleared here in Oz.

Paul Raceevo in Tasmania does them.


Paul Raceevo
20 Augusta Road
New Town TAS 7008
www.raceevo.com.au
www.airbagresets.com.au
0419 158 998



Thanks again for your reply.
John

 

[bugsymike]

Thank you very much Bugsy.
Yes my feeling is that its linked into the leisure battery to charge from alternator when driving.
But that means then that when cranking I'm drawing off both batteries?
I wonder the reason it wouldn't start was because the leisure battery also on its last legs and sucking cranking power form the new battery?
But again i had the leisure battery constantly charged form the mains plug.....but maybe its dying and not able to crank. looked good on the voltage meter but I never thought to check that as I was cranking to see if it dropped right off. Need two people to do that.

I will run the van today and see if the 'house' battery is charging with the fuse out and the mains off. That should tell me.
So the golden rule here would be 'change the main battery; change the leisure battery'?

I was psyching myself for injector removal, and most likely snapped, and thousands of dollars out of pocket. Up to $10000+
BUT I was prepared to first go through checking and swapping out the simplest to the most complex (injectors/glow plugs) to get it to start.
Just serendipity that made the fuse blow and the MHome to start.

I did notice when I put the Mutiecuscan on that the starter RPM was only about 170rpm even with a new battery.
That should have told me something but I thought 'replace the starter motor' and indeed had ordered one.

The only code that showed is the ubiquitous airbag light which has been like that for 2 years now with our lockdowns etc.
Im getting it reset/cleared here in Oz.

Paul Raceevo in Tasmania does them.


Paul Raceevo
20 Augusta Road
New Town TAS 7008
www.raceevo.com.au
www.airbagresets.com.au
0419 158 998



Thanks again for your reply.
John

Sounds like generally you head in the right direction without much help. I have worked on several vehicle with two batteries in the system where the good one is pulled down by the duff one. I may be wrong but having a leisure battery acting as a extra source of power to start the engine can cause all sorts of problems, even down to the loads put on the leisure system circuit, thinner wires not up to high amperage cranking etc.
The "split circuit system " I was thinking about was, once engine was running and charging a relay would then operate to charge the leisure battery alongside the engine battery, but importantly would only work in that direction and had a fused protection at much less than required for cranking engines.
I use a clamp on Amp meter that will work on starter leads showing up to 1000amp current, even light commercial diesels can need 600 amp on a cold start.
You may still need the new starter with all the flogging over it's had as the windings get hot and lose their lacquer insulation. After it had had some of that, it is a good idea to put your hand on the main battery leads and starter to see if anything is getting excessively hot.
Also don't let anyone keep flogging it over to start, if a diesel doesn't start in a few spins there is some thing wrong!
A genuine leisure battery is designed to give a low output for a camper etc over a long period of time, TV all night etc. The engine battery is designed to give a massive output for cranking , but only for a short time. Sorry you probably already know that

 

[Anthony489]

Hi

Just to add my thoughts to the other replies.

With motorhome conversions, the converters normally go to great lengths to prevent the "leisure" battery from back-feeding into the "vehicle battery". Charging of the leisure battery from the vehicle alternator is of course permitted when the engine is up and running. From your description, it sounds as though the measures to prevent back-feeding (split charge relay or similar) are either not fitted (unlikely) or fitted but not working as they should.

The 150A fuse protects multiple components other than the starter motor, see diagram for earlier models, yours will be similar. Sounds as though you had power from the leisure battery "downstream" of this fuse, and excess current has flowed back into the starter motor when you cranked over and blown it. This is exactly the back-feeding situation that should be prevented by design.

The cranking current for a 3 litre diesel is enormous, maybe a spike of 1000 amps and then 600 amps as it turns over. To support this, all the wiring from the vehicle battery positive to the starter motor and all the way back again to the battery negative must be in A1 condition. A peculiarity of the Ducato of this era is that all starter return current goes via a braid strap from the engine/gearbox to the body/chassis, then via a separate strap (inside the battery box) from the body/chassis to battery negative. I recommend careful inspection of the first strap, and to be honest if you are going to take it off to look properly you might as well replace it. All the other cables/straps and their connections need a careful check too, best to remove, clean and reassemble.

Depending on temperature, a diesel must be cranked over at a minimum speed for the fuel to auto-ignite from compression heat. If cranking is too slow for any reason, you could crank all day and it won't go ! I'm not a fan of Easy Start / SYB except in an emergency, as it dissolves the oil film protecting the cylinder walls which you don't want to do too often.

 

[bugsymike]

Another thing with Easy Start type products is they "force" the engine to start against it's will in effect, so it might fire when piston is still a little down the bore, unlike when the timed injector is doing it's work exactly as the piston is at it's optimum position, that is why they sometimes start with a bang which puts undue strain on the engine, in the same way tow starting diesels is not really a good thing either.
Same as any modern engine , if it doesn't start within a couple of turns, find out why!
BTW I was surprised to see a dodgy car salesman start one successfully using hairspray, so if stuck?

 

[Communicator]

Hi

Just to add my thoughts to the other replies.

================================================================================================

The 150A fuse protects multiple components other than the starter motor, see diagram for earlier models, yours will be similar.

================================================================================================

Hi,
May I respectfully suggest that the above may be in error. The 150A fuse pictured in post #1 is a cube fuse, and designed to be added directly to a stud on a battery terminal clamp, or sinilar location. I stand open to correction, but I am not aware of Fiat using this type of fuse at the battery fusebox (B099). The fuse 150A fuse (F70) is in the supply to the ignition switch, and if it was blown, both the starter motor, and the ECU would not be energised.

It is probable that the 150A cube fuse is the connection point for the habitation electrics, but 50A is a more typical value. If the split charge relay is of the voltage sensing type these seem to be rated at 120A, or more. If mains charging is applied before the voltage of the coupled batteries drops below the release voltage, then the batterries will remain coupled. This could explain the back feed from the habitation battery.

Imagine my surprise when the battery was disconnected all the dash lights, fuel transfer pump etc all came on. No battery !!
I then decided to try and turn it over since everything was lit up like a Xmas Tree.
Starter turned over over 2 times and then a large BUSS (mann?) fuse 150A 58C 28814 located on the top of the positive terminal blew.
I could see the flash.

If I am understanding this correctly, starting was attempted with the starter battery disconnected. It is not surprising that the 150A cube fuse blew, if as previously suggested a voltage sensitive split charge relay remained operated.

If the engine cranks at 150 rpm plus, the start failure is down to lack of fuel or air. One possibility is that the ECU is not being supplied with sufficient voltage to allow injection. As has been suggested by Anthony489, and others, it is worth eliminating the engine and starter battery earth connections.

With regard to the backfeed from the habitation battery, if the vehicle is fitted with a voltage sensing split charge relay, I suggest adding a control to this, so that the low current earth connection is controlled by a relay which is only operated when the ignition is on, or perhaps when D+ goes high.

 

[Anthony489]

Hi

Thanks to Communicator for clarification re 150 Amp fuse.

 

[Tallykissangel]

Sounds like generally you head in the right direction without much help. I have worked on several vehicle with two batteries in the system where the good one is pulled down by the duff one. I may be wrong but having a leisure battery acting as a extra source of power to start the engine can cause all sorts of problems, even down to the loads put on the leisure system circuit, thinner wires not up to high amperage cranking etc.
The "split circuit system " I was thinking about was, once engine was running and charging a relay would then operate to charge the leisure battery alongside the engine battery, but importantly would only work in that direction and had a fused protection at much less than required for cranking engines.
I use a clamp on Amp meter that will work on starter leads showing up to 1000amp current, even light commercial diesels can need 600 amp on a cold start.
You may still need the new starter with all the flogging over it's had as the windings get hot and lose their lacquer insulation. After it had had some of that, it is a good idea to put your hand on the main battery leads and starter to see if anything is getting excessively hot.
Also don't let anyone keep flogging it over to start, if a diesel doesn't start in a few spins there is some thing wrong!
A genuine leisure battery is designed to give a low output for a camper etc over a long period of time, TV all night etc. The engine battery is designed to give a massive output for cranking , but only for a short time. Sorry you probably already know that

Thanks again Bugsy.

Well guess what. In True FIAT Fashion it refused to start again this morning.
Its like an Agatha Christie novel.
Just when you've figured out the culprit .........well we all know the rest.

I have the mutiecuscan program and the specific leads for the Ducato but what ever it is is not showing up.

So ill keep on tracking down the culprit but with it stating no problems for a few days I still feel its electrical.
The only code I could see that excited me was re the ignition immobiliser system but there was no light on the dash.
I cleared that and put a new battery in fob.

So here i go again.
Anyhow I moved it under cover to make it more pleasant to work on.
Its cold here at the moment with daytime temps of only 16c.

 

[bugsymike]

Thanks again Bugsy.

Well guess what. In True FIAT Fashion it refused to start again this morning.
Its like an Agatha Christie novel.
Just when you've figured out the culprit .........well we all know the rest.

I have the mutiecuscan program and the specific leads for the Ducato but what ever it is is not showing up.

So ill keep on tracking down the culprit but with it stating no problems for a few days I still feel its electrical.
The only code I could see that excited me was re the ignition immobiliser system but there was no light on the dash.
I cleared that and put a new battery in fob.

So here i go again.
Anyhow I moved it under cover to make it more pleasant to work on.
Its cold here at the moment with daytime temps of only 16c.

Hopefully if no code showing it might mean a conventional mechanical/electrical issue where basic mechanics logic can play apart .
If faint immobiliser suspicion, have you a spare key?

 

[Communicator]

===============================================================================================
So ill keep on tracking down the culprit but with it stating no problems for a few days I still feel its electrical.
The only code I could see that excited me was re the ignition immobiliser system but there was no light on the dash.
I cleared that and put a new battery in fob.

================================================================================================

A common mistake, but the fob battery has no connection with the immobiliser. In my opinion, any hint of immobiliser problems needs at least to be carefully monitored. The meaning of the immobiliser related code should be determined.

(I have myself experienced a failure to start due to the key not being recognised. OK at second attempt, but after several successful starts, some failures to recognise the key when safely at home. Now seems OK, but it has got me concerned.)

 

[bugsymike]

A common mistake, but the fob battery has no connection with the immobiliser. In my opinion, any hint of immobiliser problems needs at least to be carefully monitored. The meaning of the immobiliser related code should be determined.

(I have myself experienced a failure to start due to the key not being recognised. OK at second attempt, but after several successful starts, some failures to recognise the key when safely at home. Now seems OK, but it has got me concerned.)

Always good to have a decent battery in the fob key anyway.
I have had customers where for whatever reason the immobilser had an issue with one key. I know it shouldn't as the chip in the key should be recognised by the antenae ring around the key hole and sent to the immobiliser ecu etc.
Another thing people do is have chipped keys for their other cars on the same key ring which can give a false signal.
Also with the low engine battery issue some people report immobilser issues around that time.

 

[The Panda Nut]

Just to pick at it a bit more. I think you have a lot of good advice above. I think there are some serious issues with your hab battery charging arrangements. Nothing on a hab 12v circuit requires a 150A fuse! I think the suggestion that you have no split relay on the hab charging circuit may be on the mark, I would try disconnecting said hab battery and seeing if the starting problem persists. I would also check the earthing connections on any split relay charge circuit and make sure that the hab battery charge wire is 0v with the engine off to check there is no interconection. Earth problem could explain a lot allowing current going all ways and could in this instance be a fire risk. I would expect to see nothing more than 30A fuses in hab circuits.

Do you have an on board built in charger system. I had one once and it was the only thing Ive ever know to cause problems for me with van electrics.

 

[mikefitz406]

Look at the gearbox to chassis 'earth' strap, ( visible under the air filter housing). This goes high resistance at the terminations and casues starting issues. The simple remedy is to add a further strap.
The MRBF Bussman, or 'cube' fuse that failed is part of the conversion to provide a feed to the house battery, via a relay or DC to DC converter. Who ever carried out the conversion should be able to provide support liturature.
Unless the electrical system to charge the house battery is designed correctly there may be a drain of starter battery power. However erexperience suggest to me that the earthstrap is the issue. There is a similar strap from the battery negative post to the body, this sometimes has a similar issue with the terminations.

Connecting, disconnecting and charging the engine battery without following a specific procedure can destroy the air bag computer. It canot be reset, either replacement or sometimes repair ( specialists exist in the UK).
MIKE

 

[mikefitz406]

Further thinking on your problem points to a possible issue with the fuel system injecrors, ( assuming you can rule out earth strap issues).

Replace fuel filter, have a leak off test carried out on the injectors ( no need to remove), use a diagnostic system to measure fuel rail pressure. The engine will not start unless the rail pressure is above a minimum value.

 

[Tallykissangel]

Hi

Just to add my thoughts to the other replies.

With motorhome conversions, the converters normally go to great lengths to prevent the "leisure" battery from back-feeding into the "vehicle battery". Charging of the leisure battery from the vehicle alternator is of course permitted when the engine is up and running. From your description, it sounds as though the measures to prevent back-feeding (split charge relay or similar) are either not fitted (unlikely) or fitted but not working as they should.

The 150A fuse protects multiple components other than the starter motor, see diagram for earlier models, yours will be similar. Sounds as though you had power from the leisure battery "downstream" of this fuse, and excess current has flowed back into the starter motor when you cranked over and blown it. This is exactly the back-feeding situation that should be prevented by design.

The cranking current for a 3 litre diesel is enormous, maybe a spike of 1000 amps and then 600 amps as it turns over. To support this, all the wiring from the vehicle battery positive to the starter motor and all the way back again to the battery negative must be in A1 condition. A peculiarity of the Ducato of this era is that all starter return current goes via a braid strap from the engine/gearbox to the body/chassis, then via a separate strap (inside the battery box) from the body/chassis to battery negative. I recommend careful inspection of the first strap, and to be honest if you are going to take it off to look properly you might as well replace it. All the other cables/straps and their connections need a careful check too, best to remove, clean and reassemble.

Depending on temperature, a diesel must be cranked over at a minimum speed for the fuel to auto-ignite from compression heat. If cranking is too slow for any reason, you could crank all day and it won't go ! I'm not a fan of Easy Start / SYB except in an emergency, as it dissolves the oil film protecting the cylinder walls which you don't want to do too often.

Thanks Anthony.
After it refused to start again the next day I put Multiecuscan on again and saw what I think is the problem.
The resting voltage at the ECU was around 13.4+-. I disconnected the AGM leisure battery and put on a separate charger and it’s voltage was also excellent at 13.7v.
While I had the leisure battery out I tried stating it and behold…..??? The ECU voltage was between 10.5 and 11.7+-.
Nowhere near enough. Although strange how it started after that 150A fuse blew.
I d notice that after I took it on a run that after I stopped it and came back about an hour later she was hesitant to start….sort of starting then stop. Still no codes anywhere.
So now in guessing its possible an earth strap ? Or is the ECU also earthed as well?
Is the earth strap on the 2015 Euro5 3.0L behind the kerbside headlamp (Right hand drive) ?
Thanks for all the input. It’s really very much appreciated.

 

[Tallykissangel]

Further thinking on your problem points to a possible issue with the fuel system injecrors, ( assuming you can rule out earth strap issues).

Replace fuel filter, have a leak off test carried out on the injectors ( no need to remove), use a diagnostic system to measure fuel rail pressure. The engine will not start unless the rail pressure is above a minimum value.

Hi Mike. I replaced Fuel filter and new battery the first time it refused to start. I haven’t ruled out earth strap issue as yet.
I will also get the kit to check leak off rate/volume. Fuel rail pressure is fine running but my reply to Anthony shows I have very low vomtahe at the ECU. Wouldn’t the high pressure pump not kick in if the ECU is only getting 11.5V?
?Earth strap.

 

[Tallykissangel]

Look at the gearbox to chassis 'earth' strap, ( visible under the air filter housing). This goes high resistance at the terminations and casues starting issues. The simple remedy is to add a further strap.
The MRBF Bussman, or 'cube' fuse that failed is part of the conversion to provide a feed to the house battery, via a relay or DC to DC converter. Who ever carried out the conversion should be able to provide support liturature.
Unless the electrical system to charge the house battery is designed correctly there may be a drain of starter battery power. However erexperience suggest to me that the earthstrap is the issue. There is a similar strap from the battery negative post to the body, this sometimes has a similar issue with the terminations.

Connecting, disconnecting and charging the engine battery without following a specific procedure can destroy the air bag computer. It canot be reset, either replacement or sometimes repair ( specialists exist in the UK).
MIKE

Is this strap in the same location on Euro 5 180 3.0L Multijet?

 

[Tallykissangel]

Just to pick at it a bit more. I think you have a lot of good advice above. I think there are some serious issues with your hab battery charging arrangements. Nothing on a hab 12v circuit requires a 150A fuse! I think the suggestion that you have no split relay on the hab charging circuit may be on the mark, I would try disconnecting said hab battery and seeing if the starting problem persists. I would also check the earthing connections on any split relay charge circuit and make sure that the hab battery charge wire is 0v with the engine off to check there is no interconection. Earth problem could explain a lot allowing current going all ways and could in this instance be a fire risk. I would expect to see nothing more than 30A fuses in hab circuits.

Do you have an on board built in charger system. I had one once and it was the only thing Ive ever know to cause problems for me with van electrics.

Yes I have an onboard charger to the Han battery. Also I have disconnected the hab battery and, with Multiecuscan hooked up, while starting the ECU is showing a big voltage drop from 13.7+-v to as low as 10.5+-v.
?? Earth strap.

 

[Tallykissangel]

Look at the gearbox to chassis 'earth' strap, ( visible under the air filter housing). This goes high resistance at the terminations and casues starting issues. The simple remedy is to add a further strap.
The MRBF Bussman, or 'cube' fuse that failed is part of the conversion to provide a feed to the house battery, via a relay or DC to DC converter. Who ever carried out the conversion should be able to provide support liturature.
Unless the electrical system to charge the house battery is designed correctly there may be a drain of starter battery power. However erexperience suggest to me that the earthstrap is the issue. There is a similar strap from the battery negative post to the body, this sometimes has a similar issue with the terminations.

Connecting, disconnecting and charging the engine battery without following a specific procedure can destroy the air bag computer. It canot be reset, either replacement or sometimes repair ( specialists exist in the UK).
MIKE

Yes the Airbag is annoying. It happened after someone dropped some crumbs on top of the pass air bag area. I got the Dyson out and vacuumed them up. Next time I turned it on the airbag light was there.
there’s a guy here in tassie who can reset the ECU.