C3 possible BSI failure

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Orchid70
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C3 possible BSI failure

Post by Orchid70 »

Hi
VIN on the car (model year -06) VF7**************[VIN obfuscated, can be read by forum staff]
Rear right side: turn indicator, stop, position and reverse light doesnt work.
Lights and wires/connectors have been checked by someone already.
Owner came by to have me read the fault codes.
My Diagbox wont work on these Peugeot/Citroen models on these years.
Managed to connect to the BSI through manually choosing C3R on my Autel. VIN never works on these cars.
These were the fault codes:
A4BC - turn signal rear right short to +
A4BE - brake light rear right short to +
A4C0 - position light rear right short to +
A4C7 - reverse light rear right short to +
A4C9 - fog light right rear right short to +
He has also been to Citroen, whom told that the BSI needs to be changed. But there are no BSI left at citroen and it would need to be brand new and programmed to the car.
What do you guys say?
Any chans it beeing something else? Can the BSI be repaired?
I will ask Marc for the correct part number.
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Orchid70
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C3 II Rear Light Issue

Post by Orchid70 »

Hi Marc.
It was not both turn signals that failed. But all the lights on the rear right side.
In case I will have too look for an other BSI - what would be the correct number for left hand drive, manual.
I forgot to take picture of the RPO lable.
VIN: VF7**************[VIN obfuscated, can be read by forum staff]
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GiveMeABreak
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Re: C3 II Rear Light Issue

Post by GiveMeABreak »

I've moved your post here from the parts for the moment, so you can have an opportunity to investigate the cause.

Can I suggest that you first look at BOTH rear light unit electrical connectors and check for signs of melting on the earth pin hole.

Have a look at my post here regarding this on our C3 and my fix in case it is relevant:

viewtopic.php?t=62478&hilit=melted
wheeler
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Re: C3 possible BSI failure

Post by wheeler »

My gut instinct on this is that there is nothing wrong with the BSI, Do all the other exterior lamps work as they should including the front's?
A brand new BSI in the UK is over £500 (6150 Krona) so i would be sure before going down that route.
I'll take a look at a wiring diagram when i get the chance (might not be till tomorrow) & give my thoughts.
Definitely check the earth pins though, very common for overheating.
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Orchid70
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Re: C3 possible BSI failure

Post by Orchid70 »

Absolutely!
They have had it in two places before.... The last was Citroen. They told it needed new BSI and he understood it to be the case, that none of them are beeing sold nomore here in Sweden.
Glansed at your post!! And it looks absolutely identical!
I have told them to leave the car when ever they feel for it =)
I DID tell them as well that it COULD be an earth problem somewhere between BSI and lamp. Because my gut instinct was the same - no BSI problem.
They will be very happy if its that easy.
Thank you ever so much!!
By the way - its just a bit more sophisticated fuse holder - and no coding is needed right? Just the same as when you change the melted BSM in the engine bay.
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GiveMeABreak
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Re: C3 possible BSI failure

Post by GiveMeABreak »

Can you explain a bit more - what part are you referring to that you think may need coding?

The Engine Fuse Box (BSM) doesn't need coding, but a new BSI will need coding and matching to the Engine ECU and Transponder chip - but hopefully it won't come to that...

Here's the diagram for the brake lamps for example: Pin 1 is the common earth for all the rear lights. 2630 is the rear left hand lamp cluster, 2635 is the right hand rear lamp unit.

Image
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Re: C3 possible BSI failure

Post by wheeler »

Unplug the 16 way back connector from the BSI (inside the car) feed pin 10 with 12v from the battery, if the brake lamp comes on you may have an issue with the BSI. If the brake lamp doesn’t come on then I’d say you can safley rule out the BSI being the problem.
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Orchid70
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Re: C3 possible BSI failure

Post by Orchid70 »

Thanks Marc - was looking for that, but didnt remember to take a picture of the RP number plate (I need that to be able to access Sedre).
Someone has checked the connector on the right side rear lamp with a mulitmeter. And according to owner, it was ok.
But I dont know if they checked the fuse (number 20 in BSI)! Looks like both sides have their own fuse. And: the thing I thought of: there is no right hand side fog light in Sweden! Only on the left rear, is there a fog light. But there is a fault code for it.
So, perhaps even easier: a blown fuse.
Someone has changed a bulp in the rear and after that, this happened.
Ill let you know when the car is here.

Just for my curiosity:
Can a used BSI be reprogrammed for ECU? Can the IMMO eeprom be moved to that used BSI in that case?
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Orchid70
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Re: C3 possible BSI failure

Post by Orchid70 »

Thank you Wheeler!!
I will check that out!
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Re: C3 possible BSI failure

Post by wheeler »

Orchid70 wrote:
05 Aug 2022, 21:31


Just for my curiosity:
Can a used BSI be reprogrammed for ECU? Can the IMMO eeprom be moved to that used BSI in that case?
You cant reprogram a used BSI to another car with Diagbox but yes you could swap the immo eeprom chip from the original BSI in the 'new' BSI & no matching would be needed.
The other option is to get a used matching BSI, Engine ECU & a working key from a used car as these will already be matched, The only issue is if that BSI has more miles on it your instrument panel will inherit the higher miles.
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Huskyxantia
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Re: C3 possible BSI failure

Post by Huskyxantia »

I was flagged down by a motorcyclist as my break lights were not working, mine was more simple it was the brake light pedal switch , located passenger side not above the foot brake pedal at all, french cars dont you just love em , maybe
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Re: C3 possible BSI failure

Post by ozvtr »

Orchid70 wrote:
05 Aug 2022, 18:36

These were the fault codes:
A4BC - turn signal rear right short to +
A4BE - brake light rear right short to +
A4C0 - position light rear right short to +
A4C7 - reverse light rear right short to +
A4C9 - fog light right rear right short to +
There is no ground at the tail light assembly, so the outputs (of the BSI) "float" high.
I can't see Marc's post but no doubt it's to do with the classic "melted chassis ground pin in the tail light connector". "That's the second time I fell for that this week"-Maxwell Smart.
The electrical ground contact is not rated for the load of all the lamps...gets hot... and melts the connector.
The other thing to look at is the ground point on the chassis. I think it's over the hatch area but I'm not sure. Just follow the green/yellow wire. But I'm confident Marc is right and it's the connector.
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Re: C3 possible BSI failure

Post by ozvtr »

wheeler wrote:
05 Aug 2022, 21:48
but yes you could swap the immo eeprom chip from the original BSI in the 'new' BSI & no matching would be needed.
You have to be careful here. I have found different "models" of BSI place the data on the EEPROM in different places. Then the BSI's MPU goes looking for that data in the wrong spots and it doesn't work. I'm not saying it cant be done, just saying it's not that easy.
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Re: C3 possible BSI failure

Post by ozvtr »

Orchid70 wrote:
05 Aug 2022, 21:31
And: the thing I thought of: there is no right hand side fog light in Sweden! Only on the left rear, is there a fog light. But there is a fault code for it.
If it's a requirement by law, that there is no lamp on that side, then there will be a "dummy load" in place of the fog lamp.
On the all-CAN facelift models, the BSI constantly checks the lamps by putting a 5 volt supply through the lamps. Not enough to make the lamps glow but enough to test the system. If the bulb is OK the output of the BSI goes "low", sensing the ground on the other side of the load. If there is no load I.E. the bulb is "blown" then the output stays high.
If you try to put an LED lamp in place of an incandescent bulb, the LED bulb will stay on because its being powered by the 5V supply and requires a lot less power to illuminate.
I doubt they would reprogram the BSI when they could just put a dummy load in the lamp holder (or whatever).
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Orchid70
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Re: C3 possible BSI failure

Post by Orchid70 »

So - it was the ground connector.
I pulled the lamp out and could see that the ground wire on the contact was brownish in colour. And the male connector on the lamp had been hot.
So opened the lock on the connector and took out the female ground pin. It wasnt crimping properly. So because there werent much damage, I just crimped it back tight. And everything worked again!
I guess thats the problem on at least one side. The female contact pin is not tight enough.
One side of the connector is possible to open, then its easy to lift up the locking tab and pull out the wire. You only need a thin/small flat screw driver.
Thanks for pointing me back to the connector! Even if someone already had been there, they only measured with a multi. Never looked closely. I needed to take the female pin out to be able to feel that it wasnt tight enough!
And yes - all the pulbs also were mounted on the right side (the passenger side in Sweden).