Citroen C5 BSI

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shawnwhite545199
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Joined: 03 Dec 2018, 23:35

Citroen C5 BSI

Post by shawnwhite545199 »

Just wondering i have 3 c5's and was wondering can i change the bsi from one car to another or are they programed for that pacific car i have changed it and get alot of error codes and car is in limp mode could this be the reason.

Thanks in advanced
citro6hydra
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Re: Citroen C5 BSI

Post by citro6hydra »

Hi,
The BSI is a central component in the vehicles multiplexing system and is unique to a vehicle, in that once programmed it is linked to the ECU the key set and the Vin No. Swapping to another vehicle won't work, I have heard of a company that can repair them but don't know if this includes enabling reprogramming.
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GiveMeABreak
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Re: Citroen C5 BSI

Post by GiveMeABreak »

Not only that, but there were several versions of BSI in earlier years, each having a certain level of capability, and the level of BSI fitted was dependent upon the model and options fitted. So even if a BSI was ‘virginised’ so it could be recoded, it may not be the correct version for the vehicle.

Later they began to standardise the BSI for a particular range.
wheeler
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Re: Citroen C5 BSI

Post by wheeler »

If its the same spec of car then you can swap the BSI, ECU & key transponder chip as a set & it will work in the other car. Remember though that if the donor BSI has a higher mileage than yours the car your swapping it to will (permanently) inherit the higher mileage.
On a second note though I would find it highly unlikely that the BSI is causing the car to go into limp mode. The BSI has very little to do with the running of the engine.
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GiveMeABreak
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Re: Citroen C5 BSI

Post by GiveMeABreak »

Absolutely agree - Engine backup mode / Limp home mode as it is often called is where the engine ECU will apply a reduced performance mode to allow running, but will limit revs to a maximum of circa 3000 RPM or lower. This is done to protect the engine when wither the emissions warnings have been ignored or another problem exists. It is done to limit pollution or to prevent engine damage, depending on the cause.

Your best bet is to get a proper diagnostic done and save a lot of time and money, as if the cause of the fault is not addressed, the same thing will happen after you go to the trouble of changing a BSI set out unnecessarily.
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xantia_v6
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Re: Citroen C5 BSI

Post by xantia_v6 »

But what if a mismatched BSI is fitted, would that cause the engine ECU to throw a hissy fit?
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GiveMeABreak
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Re: Citroen C5 BSI

Post by GiveMeABreak »

How do you mean mismatched Mike?

It just won't work if not matched - but I've assumed he has the limp mode issue already and is asking whether swapping the BSI out will fix it...
wheeler
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Re: Citroen C5 BSI

Post by wheeler »

xantia_v6 wrote:
17 Dec 2018, 20:39
But what if a mismatched BSI is fitted, would that cause the engine ECU to throw a hissy fit?

Do you mean one that's already been programed to another car or one that's programed & matched ok but just not the right spec for the car?
In the first case if the codes didn't match the engine just wouldn't start at all.
In the second case I still wouldn't imagine any running issues, I would have just though certain electrical functions would not work.