C3 Pluriel Electronic nightmare!!

[AllanA]

Hello all. Firstly sorry about the length of this post but I'm looking for some help with the electronics on my wifes 2007 Pluriel 1.4HDi.

Last year there was a problem with the engine sometimes running rough or just cutting out without warning. Turned out to be the reluctor ring on the crankshaft pulley. I made a previous topic on that.

With that resolved the car ran fine for about four or five months and then began to become unreliable again often with anti pollution warning flashing up on the display and various error codes diagnosed in Lexia. Once the codes were cleared and the bsi reset the car would run ok for a few weeks, or days depending how it felt. So very unpredictable.

Just before Christmas the engine wouldn't start. It would turn over but no sign of firing up so we pushed it into our garage where it still is today.

Yesterday I decided it's time to get that car running again, so key in, turned it and the engine fired up running for about four seconds. After that, nothing. The ignition lights were all on but when I turned the key the engine would not turn over and I heard a brief clicking from the engine compartment. I thought maybe the battery is discharged even though it was new last year so I turned on the head lights and they lit up fine. Turning the key with a flat battery would normally dim the lights but no, they stayed bright but the engine still didn't turn over.

So I connected Lexia, which showed up 157 fault codes including no coms with engine management, absense of +permanent on the display, power steering faults, abs faults, ecu reception no signal and also two unknown faults that showed the odometer reading at 262140km when in fact it 112652km.

I've taken photoes of the Lexia displays but think they may be too large to upload here.

Am I able to post a link on this forum to the photos on my Google Drive?

Any help with this would be much appreciated.

Currently I'm using Diagbox/Lexia v07.57 on Windows 7. Would it be any benefit to upgrade to Diagbox 9.68 Sedre version for 64 bit Windows 10 and is currently available on ebay?

[wheeler]

Currently I'm using Diagbox/Lexia v07.57 on Windows 7. Would it be any benefit to upgrade to Diagbox 9.68 Sedre version for 64 bit Windows 10 and is currently available on ebay?

For a 2007 vehicle Lexia will be absolutely fine, Diagbox want even released till late 2008.

As for all those fault codes, clear them 1st & see which ones come back after attempting to start it.
Check all the fuses.

[AllanA]

Thanks for the suggestions.

The battery is nearly new and I have pulled, checked and tested all the fuses in the engine bay and the interior fuse holder.

Tomorrow I will do a another bsi reset and try to start the engine. Will then connect Lexia and grab some screen shots to post here.

[AllanA]

OK, I pulled every fuse and checked continuity with a multimeter. I also dismantled the engine bay fuse box and checked all Maxi fuses. All ok.

Here are copies of screenshots from Lexia

[AllanA]

These are the codes left after erasing all fault codes in Lexia except these that couldn't be erased.

I then tried to start the car but same problem, I turn the ignition key and the engine does not turn over. Battery is fully charged.

Could the immobiliser cause this?

[furriegurrie]

My Pluriel had issues when I bought it. The cause was the under bonnet fusebox had had water ingress as the cover had not been fitted correctly. All fuses were fine but the print had corroded. Might be worth checking

[furriegurrie]

With issues I mean it also wouldn’t start and gave all sorts of error messages.

[AllanA]

Thanks for your suggestions. I had that apart yesterday and all looked nice and clean but I pulled all connections and refitted them and checked all the fuses and the maxi fuses too. Today I have the BSI out and checking that over.

[AllanA]

Some BSI pics showing the two boards soldered together not pressed together as in the earlier Pluriel model

[ozvtr]

Being a 2007 model, your electrics are 'all CAN'. CAN BUS is the protocol that the ECU's use to talk to each other. Previous models had a mixture of CAN and VAN BUS. That's why your BSI is different.
The BSI, ABS and the power steering ECU's are all complaining that the engine ECU is not talking to them.
Until the engine ECU is unlocked the starter wont engage. So that's normal given the circumstance.
Either the engine ECU is not working or the CAN BUS connection is cut.
Typical failure mode is moisture getting into the ABS connector and corroding the contacts. The CAN BUS to the engine ECU "piggy backs" off the ABS connector.
If that all looks ok then you will need to see if the engine ECU is getting power and ground.

[AllanA]

Hi ozvtr. Many thanks for your comments above. I refitted the BSI today and once all was connected I was really surprised, the car started and ran perfectly for some minutes. I cleared all the faults in Lexia fault log and did another diagnosis which showed no faults!! BUT then the engine stopped and same old faults flag up as before. No comms with the management ECU.

So it's really interesting that the ECU takes its feed from the ABS connection. That's where I'm going to look now and I'll update you on any findings.

[AllanA]

Well I've spent most of the day trying to figure out where the different connections are but to no avail. Just more confused!!

I know the ECU is working because the engine ran for some minutes this morning after refitting the BSI

Does anybody have a wiring diagram readily available for the CAN bus linking the ECU to other ECU's such as BSI, ABS, Power Steering please. That would help me enormously!

Also a heads up on where to look for the ABS connections. At the ABS unit itself or at the Fuse/maxi fuse box?

[ozvtr]

If you supply your VIN and ask Marc very nicely, he might be able to provide a circuit.

The ABS connector is on the ABS module. The module is located behind (and below) the passenger side (RHD car) headlight. In front of the road wheel. The connector is covered with a vinyl "bag". You'll need to cut the cable ties securing the bag over the connector. There is a big yellow locking tab retaining the connector to the module. Unlock the tab and remove the connector from the module. Look for corroded contacts. You will find grease in the connector and module but the effort is very "half arsed". The grease is supposed to stop corrosion but the application is typically not performed well.
The CAN BUS wiring to the engine ECU goes down to the ABS module then back up to the engine ECU connectors in the battery box.
OH! While you are at it, if the battery box covers are missing you might also want to check the engine ECU electrical connectors. Salty water from the road can get into the engine ECU connectors. I don't know why but people have a bad habit of just throwing away the battery box covers??!! The covers protect the engine ECU too.

[AllanA]

Hi again ozvtr. VIN for the car is VF7**************[VIN obfuscated, can be read by forum staff] and I'd really appreciate it Marc if you could provide me with circuit diagrams. (I'm asking very nicely!)

I posted today's findings on the C3 forum but I'll put it here as well in case it is helpful for other people with similar issues.

Today I spent several hours removed the battery, BSM and ECU so I could access and clean the grounding points on the inner wing below the BSM location. Refitted it all and did a BSI reset. Result was same as before. Only side lights come on, no engine turning when I turn the ignition key.

The car is in eco mode.

I checked the ECU and PS modules were grounded. Both ok.

I then pulled each fuse in the BSM, checked it and tested the viltage supply at each fuse. Strange results.

With ignition on:
F1 12.5 volts live side and 7.2 volts the other side but that gradually diminished to 0 volts a bit like a capacitor discharging
F2 0.1 volts live side 0 volts opposite side
F3 12.5 volts live side 0 volts opposite side
F4 5 volts live side 11.35 volts opposite side
F5 5.13 volts live side 0 volts opposite
F6 12.5 volts live side 1.1 volts opposite
F7 12.5 volts live side 0 volts opposite
F8 12.5 volts live side 0 volts opposite
F9 12.5 volts live side 0.9 volts opposite
F10 1.6 volts live side 0 volts opposite
F11 3.5 volts live side 0 volts opposite
F12 12.5 volts live side 0 volts opposite
F13 12,5 volts live side 0 volts opposite
F14 12.5 volts live side 0 volts opposite NO fuse at this location
F15. F16, F17 and F18 0 volts both sides

Pulled the black plug with grey and yellow wires
12.5 volts one terminal and 11.3 volts the other

I'm out tomorrow but will fire up Lexia when I get home and see what info is available.

I'm unsure how to check power and grounding at the ECU terminals. Some advice on that would be great thanks.

[AllanA]

I've checked the fuses again leaving them in place. Checked with ign ON and OFF.

OFF ON
F1 13.1 12.5
F2 0 0.1
F3 13.1 12.5
F4 0 5
F5 0 5.13
F6 0 12.5
F7 0 12.5
F8 13 12.5
F9 0 12.5
F10 0 1.6
F11 0 3.55
F12 13 12.5
F13 0 12.5
F14 NO FUSE
F15 to 10 0v

ECU
Resistance at G4 and H4 Brown connector 0 Ohms
Volts at M2, M3 Brown connector 0 Volts
Volts at C3 Black connector 0 Volts
Volts at A1 Grey (not Green) connector 10.6 Volts

Continuity betweem pin 5 of the black BSM connector and ECU M2 is good, 0 Ohms

Grounded BSM black connector pin 9 and heard relay click, checked at ECU M2 and have 12.5 volts

Tried engine start - same, no turnover.

Connected Lexia and cleared existing codes

Exited Economy mode in BSI

Ran diags again and still have no coms with ECU and no chat between ABS and PS.