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

[Tallykissangel]

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.

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.

Thanks. Even with the hab battery out it wont start and also a very big drop in voltage to the ECU once it turns over.
I now don’t think that the two batteries are connected but that’s the alternator is charging the Hab battery when running.
Still perplexed how there was enough voltage with the starter battery completely disconnected to allow turn over…
I’ll great the electrical schematics from the manufacturer to too see how it is all linked up.

 

[Anthony489]

Hi Paul

I thought it might help to draw out a simplified version of the Fiat starting and charging circuits, plus my best guess at the additions made by the Motorhome converter - see pic attached.

I have added arrows to show the main current path for the starter motor. You will see from this that any voltage drop in the earth strap will reduce the voltage available to the starter motor, and make it crank more slowly. Earth strap troubles will affect anything else that earths to the engine block, such as glow plugs and alternator. The injectors earth back to the ECU so aren't affected.

The ECU is earthed to the chassis/body, so should be unaffected by the earth strap. Its internal electronics operate at (probably) 5 volts, which is regulated down from the incoming 12 volt supply. The regulators can probably function down to as little as 8 volts, so the ECU is fairly robust to supply voltage e.g. when starting in very cold weather. The voltages you have read from MultiECUscan don't sound unreasonable and I don't think they are the cause of your problems.

I suggest you check/change the earth strap before going any further, even if only to eliminate it from the list of possibilities. It is at about shin height when standing in front of the engine, and is rather hidden under the air filter canister.

 

[Communicator]

The degradation of earth straps is not always visible. A temporary connection with a jump lead between an engine lifting lug, and a clean chassis earth, or if possible battery negative, is a common method of elimination.

If earth straps OK, then there is the remote possibility of a broken battery positive post clamp. Not easy to see.

 

[Fossickerphil]

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.

Injectors would show up more when the vehicle was running rather on start up issues. Starting on any diesel requires a glow plug system, suggest checking this system for one or more glow plugs faulty

 

[Communicator]

+++++++++++++++++++++++++++++++++++++++++++++++++++++++ Starting on any diesel requires a glow plug system, suggest checking this system for one or more glow plugs faulty

Though perhaps relevant in the current thread, not fully correct. The 2.8JTD does not use convential glowplugs.

 

[Tallykissangel]

Well more strange events.
Last time the Ducato MHome started was when I put the Multiecuscan on and checked every single relay that came up.
Yesterday it still wouldn’t start so I did the same again.
I also went into the engine fuse box and took out the large relays and checked for corrosion etc. ….. none.
Then…she started. What????????????

So I did something that allowed it to start. BUT WHAT?
I also remember last week that it came up on scan as some intermittent fault with key fob.
? Immobiliser but no light and no code coming up again…even though it wouldn’t start.

So this time I used another key…that has no chip, and the immiobilser should not allow van to start…….guess what..it did.

Left it off overnight. Just went out now and first turn of the key, the uncoded one, off it goes. Like a kitten purring.
I’m going to keep starting it every few hours and see what hat happens. Using uncover key for now.
But how is it starting with uncoded key. I’m puzzzled but content.

If it refuses to start again ill go through the same Multiecuscan procedure with the relays but try starting it after every check.
I can hear all the relays clicking or buzzing as I check them but in hindsight I should have tried starting after each one to see if that’s the issue.

 

[bugsymike]

Well more strange events.
Last time the Ducato MHome started was when I put the Multiecuscan on and checked every single relay that came up.
Yesterday it still wouldn’t start so I did the same again.
I also went into the engine fuse box and took out the large relays and checked for corrosion etc. ….. none.
Then…she started. What????????????

So I did something that allowed it to start. BUT WHAT?
I also remember last week that it came up on scan as some intermittent fault with key fob.
? Immobiliser but no light and no code coming up again…even though it wouldn’t start.

So this time I used another key…that has no chip, and the immiobilser should not allow van to start…….guess what..it did.

Left it off overnight. Just went out now and first turn of the key, the uncoded one, off it goes. Like a kitten purring.
I’m going to keep starting it every few hours and see what hat happens. Using uncover key for now.
But how is it starting with uncoded key. I’m puzzzled but content.

If it refuses to start again ill go through the same Multiecuscan procedure with the relays but try starting it after every check.
I can hear all the relays clicking or buzzing as I check them but in hindsight I should have tried starting after each one to see if that’s the issue.

Have both keys on you when out, in case it suddenly decides it wants a chipped key .
I had a Nisan Almera that had immobiliser issues and kept a laptop under the seat with Nissan Data Scan on it to delete immobilser codes so I could get home. Fault turned out to be a non standard radio!

 

[Tallykissangel]

Have both keys on you when out, in case it suddenly decides it wants a chipped key .
I had a Nisan Almera that had immobiliser issues and kept a laptop under the seat with Nissan Data Scan on it to delete immobilser codes so I could get home. Fault turned out to be a non standard radio!

Im guessing im going to have to try and get that coded key checked but ? how.
Also ill need a new coded key but don't have a clue where the code card is.
I might go back to the manufacturer of the MHome.

 

[bugsymike]

Im guessing im going to have to try and get that coded key checked but ? how.
Also ill need a new coded key but don't have a clue where the code card is.
I might go back to the manufacturer of the MHome.

Doesn't the Fiat Multiscan program have some options re immobiliser operation, check in the multiscan section of the Forum.

 

[Tallykissangel]

Wellllllllllll. Talk about frustrating.
It wont start for a week or more then out of the blue…….boom..it starts…runs like a watch.
So then I put the muktiecuscan on again and NO ERROR CODES anywhere. Apart form my 2 yr ahold airbag light.

So then I decided to test all the relays etc. As I went though them and executed the actuators I listened to every one doing its stuff. Then when all done I turned it over and voila ……..it’s started.

So then I waited another few days until it wouldn’t start and used MEC to actuate each relay/sensor/regulator .
After each actuation I tried stating it. NOTHING…..until I tried the high pressure fuel regulator. Then it started.
All this time no error codes anywhere.

So I left it another 48 hrs. Van wouldn’t start. Actuated the high pressure fuel relay/sensor. It started straight away

So now I’m confused big time. With no error code is the HP regulator stuffed???
And if its is why is it when I actuate it it works. Allowing fuel to HP rail?
Should I replace it. AND……is it the regulator on the HP pump or the common rail?

Any advice gratefully received.

 

[Tallykissangel]

Doesn't the Fiat Multiscan program have some options re immobiliser operation, check in the multiscan section of the Forum.

It does indeed but to scared to do anything with the one key I have.

 

[Anthony489]

Hi

The High Pressure Flow Regulator is an actuator valve that controls fuel flow from the LP pump to the HP pump. It is controlled by the ECU using a Pulse Width Modulated (PWM) signal at typically 1 kHz, i.e. it can be controlled continuously from fully on to fully off and anywhere in between. Sometimes referred to as a Suction Control Valve (SCV). This device fits onto the body of the HP pump and is sealed by O - rings. I don't know what condition or range of conditions are exercised when actuated by MultiECUscan.

If it is faulty (sticking ?) one would expect the HP common rail pressure to be wrong, which would be sensed by the rail pressure sensor and the ECU would throw an error code. If the rail pressure is too low the engine is prevented from starting, but I suspect that if the engine is already running it won't be stopped as that could be hazardous when driving. Price roughly £50 to £100 so may be worth a gamble to change it anyway.

The following background notes are adapted from Pico Auto:

Within a common rail diesel system, the Engine Control Unit (ECU) uses a pressure regulator valve to control the fuel pressure within the common rail. When the ECU needs to reduce the pressure, the valve is opened and excess fuel is released to the fuel return system. Conversely, when an increased pressure is needed, the valve is closed.

The pressure regulator valve position is determined by the action of a solenoid against a spring. With these devices, the valve will move from its default position, open or closed depending on the application, when current flows through the solenoid. The greater the current, the greater the displacement of the valve. Thus, in some systems an increase in current will cause the valve to become more open, whereas in others it will cause the valve to become more closed.

The ECU can efficiently control current in a circuit using a PWM signal and, for a given electrical load, the greater the duty period, the greater the average current flowing through the circuit.

With a switched earth activated circuit the solenoid is fed with a constant battery positive on one side and, on the other side the ECM modulates the path to earth creating current flow. Therefore, the valve is energised on when the actuation signal is at battery negative voltage and de-energised off when the actuation signal is at battery positive voltage. Hence the greater the duty cycle, the greater the current in the circuit and the displacement of the valve from its default position.

The ECM will vary the duty depending on the engine speed, load and temperature conditions and the torque demand from the driver via accelerator pedal position.

Refer to vehicle technical data for specific test conditions and results.

 

[Tallykissangel]

Hi

The High Pressure Flow Regulator is an actuator valve that controls fuel flow from the LP pump to the HP pump. It is controlled by the ECU using a Pulse Width Modulated (PWM) signal at typically 1 kHz, i.e. it can be controlled continuously from fully on to fully off and anywhere in between. Sometimes referred to as a Suction Control Valve (SCV). This device fits onto the body of the HP pump and is sealed by O - rings. I don't know what condition or range of conditions are exercised when actuated by MultiECUscan.

If it is faulty (sticking ?) one would expect the HP common rail pressure to be wrong, which would be sensed by the rail pressure sensor and the ECU would throw an error code. If the rail pressure is too low the engine is prevented from starting, but I suspect that if the engine is already running it won't be stopped as that could be hazardous when driving. Price roughly £50 to £100 so may be worth a gamble to change it anyway.

The following background notes are adapted from Pico Auto:

Within a common rail diesel system, the Engine Control Unit (ECU) uses a pressure regulator valve to control the fuel pressure within the common rail. When the ECU needs to reduce the pressure, the valve is opened and excess fuel is released to the fuel return system. Conversely, when an increased pressure is needed, the valve is closed.

The pressure regulator valve position is determined by the action of a solenoid against a spring. With these devices, the valve will move from its default position, open or closed depending on the application, when current flows through the solenoid. The greater the current, the greater the displacement of the valve. Thus, in some systems an increase in current will cause the valve to become more open, whereas in others it will cause the valve to become more closed.

The ECU can efficiently control current in a circuit using a PWM signal and, for a given electrical load, the greater the duty period, the greater the average current flowing through the circuit.

With a switched earth activated circuit the solenoid is fed with a constant battery positive on one side and, on the other side the ECM modulates the path to earth creating current flow. Therefore, the valve is energised on when the actuation signal is at battery negative voltage and de-energised off when the actuation signal is at battery positive voltage. Hence the greater the duty cycle, the greater the current in the circuit and the displacement of the valve from its default position.

The ECM will vary the duty depending on the engine speed, load and temperature conditions and the torque demand from the driver via accelerator pedal position.

Refer to vehicle technical data for specific test conditions and results.

Thanks Anthony extremely useful information. You must work in the industry?
There are no error codes re relays or regulators so thats throwing me off.
Just the Airbag.

I agree Im going to replace the HPF regular and see what happens.
So many times in the past months Ive thought I'd hit the jackpot re starting it only to have the FD refuse to start again.
At least this time evrey time its not started I just actuate the HPF regulator and away it goes.

What I dont need to to be is somewhere remote and have it happen again.
Australia is a very very big place. 7 hrs from where we live to Sydney and 3 days to Cairns.
So Im trying to recreate the van not starting as many times as possible and see if it throws a DTC or anything and also that I can start it.
Im also going to have my laptop with MES and the 3 OBD cables on board whenever I travel......even to the shops.

My seriously paranoid plan is to have a spare of every sensor, relay and regulator as well as a starter motor.
Did I mention spare fuses??
Way cheaper in the long run.
Thanks again

 

[Tallykissangel]

Well sorry its been a while since I posted about DEYZEE the MHome. Covid and the expalanation below.

Well a lot has happened and some not so good. In fact disastrous. Our roads here i Oz are shocking. Potholes like the Grand Canyon, and I exaggerate not, everywhere.
So first thing first.
I originally was posting about how I could not start the van and then out of the blue it would start. Looked at everything every FF memeber recommended, I mean everything.
Then out of curiosity more than anything I used MutiECUscan again. I started going through the actuators one by one.
when i went to the High Pressure Fuel regulator and actuated it ,.....IT STARTED, start away.
It then stated no problems for weeks.
Then the next time it wouldn't start I actuated the low pressure regulatro...no start.
then the HP regulator ….away she went.
So any time now it won't start out comes the laptop and MES and away DEYZEE goes.
Next step is to put new HP regulator in.

So back to the put holes.
I noticed just before Xmas DEYZEE wandering, over steering on corners.
Went to get new tyres .
Fitter said " your shocker has come away form the mounting bracket, cast iron/steel.
Sure enough bracket snapped clean off.
Got new ALKO shockers and a lower cast bracket and put them on.
Looked at them a week later after a really really bad pot hole and guess what.
Both broken, bent and brackets (cast) bent.
I went to Melb and the grating noises from the back were worrying.
Eventually I couldn't drive they were so bad coming from the back

Got under DEYZEE.
Both shockers now stuffed.
Cause???
Broken torsion bar in ALKO axle and top and bottom mounting brackets stuffed bent and the top ones cracked/splitting

After $4600 left my wallet to go to ALKO, I got that back from CIL insurance , a great insurance company, mechanic fitted the axle for me.
Took about 4 hrs.
Drives like new...which it is.

Moral of the story.
if you have an ALKO chassis and suspension set up get under and check shock absorber brackets.
Both top and bottom.
Look for twisting or cracks on the top ones. If it wasn't for the young tyre fitter and his observations i probably would have wandered over onto the other side of the road with a truck bearing down on us

Oh and so NEVER EVER drive you MH when its dark....at least not in Australia

 

[Tallykissangel]

Hi

The High Pressure Flow Regulator is an actuator valve that controls fuel flow from the LP pump to the HP pump. It is controlled by the ECU using a Pulse Width Modulated (PWM) signal at typically 1 kHz, i.e. it can be controlled continuously from fully on to fully off and anywhere in between. Sometimes referred to as a Suction Control Valve (SCV). This device fits onto the body of the HP pump and is sealed by O - rings. I don't know what condition or range of conditions are exercised when actuated by MultiECUscan.

If it is faulty (sticking ?) one would expect the HP common rail pressure to be wrong, which would be sensed by the rail pressure sensor and the ECU would throw an error code. If the rail pressure is too low the engine is prevented from starting, but I suspect that if the engine is already running it won't be stopped as that could be hazardous when driving. Price roughly £50 to £100 so may be worth a gamble to change it anyway.

The following background notes are adapted from Pico Auto:

Within a common rail diesel system, the Engine Control Unit (ECU) uses a pressure regulator valve to control the fuel pressure within the common rail. When the ECU needs to reduce the pressure, the valve is opened and excess fuel is released to the fuel return system. Conversely, when an increased pressure is needed, the valve is closed.

The pressure regulator valve position is determined by the action of a solenoid against a spring. With these devices, the valve will move from its default position, open or closed depending on the application, when current flows through the solenoid. The greater the current, the greater the displacement of the valve. Thus, in some systems an increase in current will cause the valve to become more open, whereas in others it will cause the valve to become more closed.

The ECU can efficiently control current in a circuit using a PWM signal and, for a given electrical load, the greater the duty period, the greater the average current flowing through the circuit.

With a switched earth activated circuit the solenoid is fed with a constant battery positive on one side and, on the other side the ECM modulates the path to earth creating current flow. Therefore, the valve is energised on when the actuation signal is at battery negative voltage and de-energised off when the actuation signal is at battery positive voltage. Hence the greater the duty cycle, the greater the current in the circuit and the displacement of the valve from its default position.

The ECM will vary the duty depending on the engine speed, load and temperature conditions and the torque demand from the driver via accelerator pedal position.

Refer to vehicle technical data for specific test conditions and results.

Thanks Anthony. Very very valuable advice. Buying these bits in Oz is like buying diamond studded hens teeth. Often quicker to buy for UK or EU.