Citroen C2 - dead electrics - No power to locks, interior light, ignition - everything dead

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napping
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Re: Citroen C2 - dead electrics - No power to locks, interior light, ignition - everything dead

Post by napping »

Dormouse wrote:
12 Dec 2021, 16:53
Is this voltage tested between pins 5 & 6 and 5 & 14?
Voltage was tested between 6 and earth, and 14 and earth (earthing point in footwell, the same earthing point that gave 12.8v for F17.
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Re: Citroen C2 - dead electrics - No power to locks, interior light, ignition - everything dead

Post by Dormouse »

pin 5 is the signal earth I believe. Wheeler? Which pins for Can voltage?
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Re: Citroen C2 - dead electrics - No power to locks, interior light, ignition - everything dead

Post by moizeau »

Way above my spannering threshold but following, all the very best
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Re: Citroen C2 - dead electrics - No power to locks, interior light, ignition - everything dead

Post by Dormouse »

Welcome to the world of modern cars. I gave up Diagnostics professionally 30 years ago and stuck to tuning competition cars and restoring vintage/classic cars. I still "dabble" but the complexities are just increasing all the time. God help us when cars and lorries drive themselves.
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Re: Citroen C2 - dead electrics - No power to locks, interior light, ignition - everything dead

Post by napping »

Dormouse wrote:
12 Dec 2021, 17:08
pin 5 is the signal earth I believe. Wheeler? Which pins for Can voltage?
Yep, tried pin 5 as earth to pins 6 and 14 too and still no voltage.
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Re: Citroen C2 - dead electrics - No power to locks, interior light, ignition - everything dead

Post by Dormouse »

Looks to confirm no CANBUS dialogue. Have you tried to power up F13 temporarily yet?
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Re: Citroen C2 - dead electrics - No power to locks, interior light, ignition - everything dead

Post by napping »

Dormouse wrote:
10 Dec 2021, 09:56
Is it worth supplying a temporary power lead to F13 to see if the BSI comes to life?
I should get a power lead with swappable mini fuses tomorrow. If so, will test this when I can.
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Re: Citroen C2 - dead electrics - No power to locks, interior light, ignition - everything dead

Post by Dormouse »

Now. I don't know this so maybe someone will jump in here. Are pin 5 and pin 4 connected to the same ground and, if so, how is the ground connection achieved. Especially for pin 5.
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Re: Citroen C2 - dead electrics - No power to locks, interior light, ignition - everything dead

Post by wheeler »

Dormouse wrote:
12 Dec 2021, 19:17
Now. I don't know this so maybe someone will jump in here. Are pin 5 and pin 4 connected to the same ground and, if so, how is the ground connection achieved. Especially for pin 5.
If you look at the diagram i posted on the last page both 4 & 5 are connected directly to the chassis (at different points) but the same earth points also provide earths for the BSI & BSM.
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Re: Citroen C2 - dead electrics - No power to locks, interior light, ignition - everything dead

Post by Dormouse »

GiveMeABreak wrote:
02 Dec 2021, 11:35
I'll save you the time Wheeler.

Image

-M000 battery earth
-MC10 front left earths
MC11
MC12
MC14
MC15
-MC20 front right earths
-MC30 front left earths (dashboard)
MC31
MC32
MC33
-MC34 centre console earths
MC35
-MC40 front right earths (dashboard)
-MC50 central cabin earths
-MC60 left rear earths
MC75
-MC70 right rear earths
-MM02 engine earth

Image
On this diagram where do each set of earths actually attach to. Especially pin 5
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Re: Citroen C2 - dead electrics - No power to locks, interior light, ignition - everything dead

Post by GiveMeABreak »

This is just the overall earthing diagram for the OPs vehicle. It is not for anything else apart from showing the location of all the earth points. That diagram underneath was separate - an extract of the location of the harness or equipment being referred to back early in the post (I don't have time to re-read it all now). As an example, Harness 46HAB in the lower right image is earthed at MC35. MC35 is shown on the large diagram as being on the right side of the gearbox binnacle. So any equipment that is connected to harness 46 HAB will be earthed at this point.
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Re: Citroen C2 - dead electrics - No power to locks, interior light, ignition - everything dead

Post by napping »

Looking at the BSI circuit, could the problem be relay R7 in the BSI? I'm no expert but it seems it could cause the symptoms of power to the ignition switch, F11 and F8, but no power to F13 and F14, etc. ??
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Re: Citroen C2 - dead electrics - No power to locks, interior light, ignition - everything dead

Post by Dormouse »

check the continuity of pin 5 to earth. If that is sound and there is no Canbus power at 6 and 14 then that is a major issue. If the pin 5 continuity is poor then track down the Canbus earth (pin 5 is an extension of it but the actual earth connection) A "cheat" here if pin 5 has poor continuity is to connect the Canbus earth by earthing pin 5 but, if the fault is further into the Canbus system, earthing the physical wires still won't connect the Canbus. All of this will help locate the area of the fault whatever the outcomes.
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Re: Citroen C2 - dead electrics - No power to locks, interior light, ignition - everything dead

Post by Dormouse »

After that, power up F13. Your relay R7 could a possibility. but all of the things above are quick and easy to do and provide more grid points to narrow down the area of the fault.
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Re: Citroen C2 - dead electrics - No power to locks, interior light, ignition - everything dead

Post by ozvtr »

napping wrote:
13 Dec 2021, 00:09
Looking at the BSI circuit, could the problem be relay R7 in the BSI? I'm no expert but it seems it could cause the symptoms of power to the ignition switch, F11 and F8, but no power to F13 and F14, etc. ??
The ignition switch power comes from the battery + to maxi fuse #4 to fuse F11 in the BSI then to the switch (pin3 not pin2!!!!!!). So it doesn't touch R7.

Relay R7 supplies power to F13 and F14 (in the BSI). I believe F13 is the main power source for the BSM's electronics. I can see nothing else that the BSMs electronics (not the relays) would use as a power source. F14 supplies power to the central display and the main instrument cluster. And R7 is controlled by the BSI internaly.
Yes, it's possible the contacts or coil of R7 have burnt out and it is not supplying power to the dash and BSM. Therefore the dash, central display and BSM do not get any power and don't work. On the surface this simulates your fault quite well. But why doesn't the interior light come on? Why don't the doors unlock? The door lock circuit (provided by wheeler) is unclear as to the power supply for the interior light, but I would assume that's on a permanent battery supply (I.E. not R7) as the light (normally) can be turned on and off at any time. The supply for the door locks is from F16(or F15, I can't quite make it out). Again not connected to R7.

Actually, I just had a thought. Under ANY condition the interior light should work!? Anyone disagree? Anyone think of a circumstance under which the light shouldn't come on (come on, be reasonable :-D no fuses, switches or blown bulbs...think ). So I cant see anything external to the BSI that would hold the BSI in sleep mode (or whatever) AND stop the interior light from working. It should always work. Even if the CAN BUS or other stuff is not working.
So the way I see it, you have good permanent power on the pins of the 2 pin grey connector, good earths on 6 and 8 of the green 16 pin connector. So why doesn't the interior light come on, when there is nothing to stop it?

From what I can see the whole damn show is run by one giant chip on the main PCB of the BSI. Either it's gone wheels up or a power supply (for the chips) has gone out. Again, just my opinion from what I can deduce. Happy for anyone to critique me.