Berlingo 1.6Hdi multispace - intermittent fault codes

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mcdos
Donor 2021
Posts: 7
Joined: 26 Jul 2021, 12:01

Berlingo 1.6Hdi multispace - intermittent fault codes

Post by mcdos »

Hello,
I have a 2014 1.6 HDi XTR with some unusual fault codes popping up intermittently:

9months ago:
Car went into limp mode, specific fault not recorded as had driven to local garage who just reset it and sent us on our way indicating the fault was not present anymore.

1 month ago - van into limp mode:
C1391 - None confirmation of engine torque (no speed recorded from any wheel at the time of the fault)
P0265 - Injector 2 short circuit intermittent
P0494 - Fan speed error
Car seemed a bit rough whilst driving in limp mode, but this may be normal?

Reset the fault as none were still present Car ran like normal until last week when it went into limp mode yet again, this time whilst on the motorway:
C1391 - None confirmation of engine torque (no speed recorded from any wheel at the time of the fault)
P0262 - Injector 1 short circuit intermittent
F997 - Horns control fault
Rescued off motorway and at the time the rescue tech seemed to think van was only working on three cylinders during his initial diagnosis, but when he offloaded it, it seemed to be running ok again.

Not had another go with it just yet, trying to mull the most likely failure. It would be easy just to assume an injector is faulty, but having looked back through the diagbox history things are not so clear. My initial suspicion is a wiring fault somewhere or possibly an ECU fault as its hard to believe that two injectors would have exactly the same intermittent fault in such a short space of time/distance and be fine in-between or that all four wheel sensors could fail at once and again be fine in-between.

If anyone has had any similar experiences they are willing to share, I'm all ears.

The main issue for me now is to find a wiring diagram to do a bit of harness/connector checking. Any ideas where I might find one for this particular vehicle?
mcdos
Donor 2021
Posts: 7
Joined: 26 Jul 2021, 12:01

Re: Berlingo 1.6Hdi multispace - intermittent fault codes

Post by mcdos »

Update,
Cleared the C1391 and P0262 fault codes and its running fine yet again, no misfiring or anything untoward. Had a look at the injectors and no signs of any obvious cable damage or oil/leakages etc in the injector area. So, I'm a bit stuck for the moment.
RichardW
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Re: Berlingo 1.6Hdi multispace - intermittent fault codes

Post by RichardW »

Early DV6C engines are prone to injector failure. Although yours is not that early being 2014 - I suspect that is most likely the cause of the troubles.
mcdos
Donor 2021
Posts: 7
Joined: 26 Jul 2021, 12:01

Re: Berlingo 1.6Hdi multispace - intermittent fault codes

Post by mcdos »

RichardW, I would agree its a strong likelihood and if it was throwing the fault at the same injector I would certainly plum for putting a replacement in. I'm still not discounting it, but two different injectors throwing up similar "very" intermittent faults is either really bad luck or perhaps is due to something else. Why does a shorted injector throw the C1391 fault at the same time? That seems pretty weird.

I don't want to throw £600 away on new injectors just to fault find that it is something else in the system causing this issue... It would, of course, be easier if the fault wasn't intermittent.

Thanks for your input though.
mcdos
Donor 2021
Posts: 7
Joined: 26 Jul 2021, 12:01

Re: Berlingo 1.6Hdi multispace - intermittent fault codes

Post by mcdos »

RichardW, Took the car along to the local diesel specialist yesterday and had them do an insulation test and resistance test on all four injectors in situ. All were pretty much the same >300MOhm insulation and 200kOhm resistance. Not a conclusive test, but a start. They can do a full out of car test if required, but at £200 that's half the cost of just replacing the two suspect injectors....

Took a look on the diagbox and there are no injection anomalies between the injectors on idle either as far as I can see, all within a gnats whisker of each other. Car was fine for 20mile round trip to do the test.

So, injector failure is not discounted, but as yet not obviously the cause and we still have the unusual situation of two having gone down in quick succession, but working fine in between.

One thing I would like to check though, the diagbox was indicating the injector voltage as 200V and from what I can find on the web, piezo injector voltages are more typically 100-120V. Does anyone out their know what the correct injector voltage should be for this car?

My thinking is that if this was too high it might be stressing the insulation in the injectors....
mcdos
Donor 2021
Posts: 7
Joined: 26 Jul 2021, 12:01

Re: Berlingo 1.6Hdi multispace - intermittent fault codes

Post by mcdos »

I carried out some further measurements on the injectors and came up with the following results:
table.JPG
The two that have tripped the ECU are INJ 1 and INJ2 we can see there is a subtle difference between the "coil" resistance of these two versus the other two. However, all are still within the tolerances put forward in the P0262 diagnosis tree, an extract of which is included below. The engine is running fine with balanced operation at all other times. The insulation values above include the ECU to injector wiring harness and this has been inspected to verify there is no damage or contamination etc.
fault tree.png

So, currently, without any clarity on the normal operating voltage for these injectors, my suspicion is that Injectors 1 & 2 are in the process of failing, which is in line with RichardW's initial diagnosis, and I assume the ECU voltage I'm seeing is normal otherwise it should show up as an ECU error.

However, as it stands, the fault tree would direct me just to replace the ECU.

Both are costly experiments to get wrong, so it would be really good to have some form of confirmation regarding the normal peak voltage levels the SID 807 ECU puts out to these injectors Part no: 9802448680 (Siemens VDO part No. A2C59513556).
mcdos
Donor 2021
Posts: 7
Joined: 26 Jul 2021, 12:01

Re: Berlingo 1.6Hdi multispace - intermittent fault codes

Post by mcdos »

Ok, so I have now carried out scope voltage and current measurements on the car and can confirm that the control voltage reported in diagbox is not the voltage which ends up at the injectors:
20210802-0001 injector 1 v2.jpg
Injector 1 (suspect)
20210802-0001 injector 4 v2.jpg
Injector 4 (assumed ok)
Here we can see that the peak voltage at the injectors is around 117V. So I assume the internal ECU power electronics structure is such that the injector peak voltage is limited to approximately half the value reported in diagbox. So my initial concern was unfounded. Occupational hazard of trying to learn as you go along....

Reassuringly, my scope plots are actually quite similar to the one published by markstammersdiagnostics.

Needless to say, there is very little obvious difference in the scope traces between the "failing" injectors and the "good" injectors so its still a difficult call as to what's actually going on.

Intermittent faults are just the worst!
Gillianfreynolds
Posts: 1
Joined: 03 Nov 2021, 11:26

Re: Berlingo 1.6Hdi multispace - intermittent fault codes

Post by Gillianfreynolds »

Hello
Your post was very interesting and useful, thank you. I wonder if you have solved the problem because it sounds identical to what nightmare I have been facing with my Berlingo. I have already replaced one injector and it has not solved the problem. The ECU was replaced one year ago. Any help gratefully appreciated as I am a driver not a trouble shooter! Thanks