Intermittent faults - limp mode

[mcdos]

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

9months ago:
Van 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
Van seemed a bit rough in limp mode, but this may be normal?

Reset the fault as none were still present van ran like normal until last week when it went into limp mode again 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.

It would be easy to assume an injector was 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 the same intermittent fault in such a short space of time 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 vehicle? Is the one in the Haynes manual any good for this vehicle?

TIA

[pluggit1]

Looking at those I would say they are more "random" than a pattern. Do your basics first. Pull the ECU conns and spray with contact cleaner NOT Wd type spray, it leaves too much residue and can have an insulating effect on low voltage stuff making the problem potentially worse. Work your way methodically back from the ECU to everything you can get at. Try all that first and see how it goes.

[mcdos]

Looking at those I would say they are more "random" than a pattern. Do your basics first. Pull the ECU conns and spray with contact cleaner NOT Wd type spray, it leaves too much residue and can have an insulating effect on low voltage stuff making the problem potentially worse. Work your way methodically back from the ECU to everything you can get at. Try all that first and see how it goes.

Hi Pluggit1, agreed they are a bit random. Reset the two main faults again (C1391 and P0262) and its all working fine, till the next time.... 

Took a general look at the injector wiring, all looks good had a nosey about the ECU and fusebox, nothing obvious in there either. ECU looks to be buried in a tamperproof cage. When I get hold of a diagram and have a bit more time I'll try to have a better poke about the connectors and cabling.
Thanks for the response :-)

[pluggit1]

ECU,s are pretty bomb-proof so that would be way down my list of suspects - but only as good as the interconnections. We have a guy up here who is the Guru on these marks. Why not give him a bell. Lloyds Citroen/Peugeot Swansea.

He,s a one man band outfit and forgotten more than most people know about these vehicles.

Meanwhile just set on the multi-blocks and connectors with some cleaner and a toothbrush.

[cancunia]

ECU,s are pretty bomb-proof so that would be way down my list of suspects - but only as good as the interconnections. We have a guy up here who is the Guru on these marks. Why not give him a bell. Lloyds Citroen/Peugeot Swansea.

He,s a one man band outfit and forgotten more than most people know about these vehicles.

Meanwhile just set on the multi-blocks and connectors with some cleaner and a toothbrush.

If you PM me your VIN, I'll see if I can find the ECU wiring. It may not be possible due to the age but I'll have a look.

Here's a diagram attached from a 1.6 M59 that may be of use.

[Pedronicus]

ECU,s are pretty bomb-proof so that would be way down my list of suspects - but only as good as the interconnections. We have a guy up here who is the Guru on these marks. Why not give him a bell. Lloyds Citroen/Peugeot Swansea.

He,s a one man band outfit and forgotten more than most people know about these vehicles.

Meanwhile just set on the multi-blocks and connectors with some cleaner and a toothbrush.

If you PM me your VIN, I'll see if I can find the ECU wiring. It may not be possible due to the age but I'll have a look.

Here's a diagram attached from a 1.6 M59 that may be of use.

A 2014 B9 is Old?????

[mcdos]

ECU,s are pretty bomb-proof so that would be way down my list of suspects - but only as good as the interconnections. We have a guy up here who is the Guru on these marks. Why not give him a bell. Lloyds Citroen/Peugeot Swansea.

He,s a one man band outfit and forgotten more than most people know about these vehicles.

Meanwhile just set on the multi-blocks and connectors with some cleaner and a toothbrush.

If you PM me your VIN, I'll see if I can find the ECU wiring. It may not be possible due to the age but I'll have a look.

Here's a diagram attached from a 1.6 M59 that may be of use.

Thanks Cancunia, It might be of some use, sent you a p.m in case you can find the correct diagrams. TIA

[cancunia]

ECU,s are pretty bomb-proof so that would be way down my list of suspects - but only as good as the interconnections. We have a guy up here who is the Guru on these marks. Why not give him a bell. Lloyds Citroen/Peugeot Swansea.

He,s a one man band outfit and forgotten more than most people know about these vehicles.

Meanwhile just set on the multi-blocks and connectors with some cleaner and a toothbrush.

If you PM me your VIN, I'll see if I can find the ECU wiring. It may not be possible due to the age but I'll have a look.

Here's a diagram attached from a 1.6 M59 that may be of use.

A 2014 B9 is Old?????

Nope, too new for my version of Service Box

[mcdos]

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....

[cancunia]

Did the fault codes you mention come up on Diagbox, or a generic OBD reader? I'm wondering if you do a scan from Diagbox when you get limp mode again that you may get some different info.
As to the voltages, sorry, no idea.