Xsara Keys

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RichardW
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Xsara Keys

Unread post by RichardW »

My Dad is having trouble with the keys on has 2002 Xsara. He had a new alternator a few months back, after which none of the keys would open the car (don't know which would start it). He got at least one of the keys reprogrammed and working, but is now trying to get the rest going, as he is selling the car to my Sister in a few weeks. He took it to the autosparks, but he's saying the BSI won't recognise the security code, so he can't reprogramme the keys :? Anyone know if you can force a re-set on the BSI ( :twisted: ) then reprog all the keys, or if it's knackered now, or if a proper Lexia would do any better?
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Unread post by citronut »

a LEXIA should be able to sort it out, were abouts is the car may be its near one of us LEXIA/DIS-LEXIA owners,

i need some guinea pigs at a resonable rate you understand

regards malcolm
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Paul-R
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Unread post by Paul-R »

There are two aspects to consider.

1) Does the car turn in the column lock and start the car? If it doesn't a Lexia is neede to pair the key to the car.

2) Does the remote lock/unlock function work? If it doesn't, and providing aspect 1 is working, then you pair the key to the car by inserting the key into the column lock, press the unlock button on the key fob and turn the key to the ignition position. Keep the button pressed in for 5 - 10 seconds and then let go. The remote locking should now also be paired. A lexia is not needed for this.
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nick
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Unread post by nick »

Sounds very much like what happened to my Xsara after the battery was disconnected. The BSI can 'forget' the key codes.

The procedure Paul gives above is to get the remote locking working again after the battery in the key has been replaced.
If the car battery has been disconnected and the BSI has forgotten the codes unfortunately this procedure often won't work. For that you do need a Lexia and the original code card that came with the car.

It is possible for the BSI to still recognise the key code sufficiently to disarm the immobiliser and start the engine, but not to allow the remote locking to work. How and why this is possible I don't know, but it's what my Xsara did, and seems quite a common problem on Xsaras of this age.

I got a Citroen dealer to do mine and they had a heck of a problem to get the BSI to take the code, but they tried it over and over again, and eventually the BSI accepted it. It took them all afternoon, but in fairness they only charged for half an hour's labour.
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Paul-R
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Unread post by Paul-R »

nick wrote:If the car battery has been disconnected and the BSI has forgotten the codes unfortunately this procedure often won't work. For that you do need a Lexia and the original code card that came with the car..
Well I've never had that happen to me. When I took the gearbox out of the Xsara a few months ago the battery was disconnected for about 5 - 6 weeks and all I nneded to do was re-pair the key fob.

Also, I collected a non-starting C5 this weekend with a view to breaking for spares. There was no battery in it and hadn't been for 2 - 3 months. The chap who sold me the car connected the C5 to his car with jump leads and after about 5 minutes I was able to re-pair the key fob so that I could lock and unlock the car to open the tailgate.
nick wrote:It is possible for the BSI to still recognise the key code sufficiently to disarm the immobiliser and start the engine, but not to allow the remote locking to work. How and why this is possible I don't know, but it's what my Xsara did, and seems quite a common problem on Xsaras of this age.
I wonder if this is really a common problem or something specific to yours? Anyone else have a problem with re-pairing a key fob that only a Lexia could sort out?
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Inside every old person is a young person wondering what the hell happened.

"Trying is the first step towards failure" ~ Homer J Simpson
nick
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Unread post by nick »

The dealer thought the problem on mine originated from a fast fit place not allowing the BSI time to shut down before whipping the battery leads off. I have disconnected the battery numerous times myself since, but always allowing the BSI time to shut down first, and not had this problem again. I don't think its the length of time the battery is left disconnected, but the procedure followed when disconnecting the battery.

The reason I've come to think this is perhaps a common problem is I've known about half a dozen or so cases of exactly the same thing being reported on other car forums, always with Citroen Xsaras built between 2001 and 2002. One poster said a dealer told him that this particular age of Xsara was known to them for doing this and is often a sod to get the keys programmed in again!
The trigger usually seems to be disconnecting the battery, though one was caused by the Xsara being used to jump start another car, and another was a loose battery lead.

I've never heard of this on a C5 though, my dads C5 HDI had a loose battery lead which caused a number of other temporary problems, but didn't cause the remote locking to pack up like this.
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Unread post by citroenxm »

Paul-R wrote:There are two aspects to consider.

1) Does the car turn in the column lock and start the car? If it doesn't a Lexia is neede to pair the key to the car.

2) Does the remote lock/unlock function work? If it doesn't, and providing aspect 1 is working, then you pair the key to the car by inserting the key into the column lock, press the unlock button on the key fob and turn the key to the ignition position. Keep the button pressed in for 5 - 10 seconds and then let go. The remote locking should now also be paired. A lexia is not needed for this.
Paul!
This is wonderfull! Ive just done this now with a Xsara here, that started the car, but the PLIP after a battery change had stopped working, did this, key in, button pressed for ten seconds, and hey presto the locking worked again!

Cheers, saved me a lot of hassles!

Paul
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jopis8
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Re: Xsara Keys

Unread post by jopis8 »

I'm reviving this old thread....

I've transfered everything from my spare parts car onto my car. Xsara 2.0hdi 2004. Bsi, bsm, ignition, code reader (black round part standing on ignition), keyfob.
But my car wont start, i have after few seconds trying to start my car, error lamp on my instrument panel, showing that keycode isnt recognized.
I have no lexia, i have delphi diagnostics, i've deleted all error codes, but they are showing up again, inbetween all of them, there are 2 about imobilisator - one error is permanent, second isnt. About low power to imobilisator.
Do i have to call dealer for security code and enter it for keys in delphi's section for entering new keys in imobilizer, or there is another ghost in my car?
Second question is, is there something else where imobilizer stores its data? I've transfered everything what i thought that has any connection with it - bsi, bsm, ignition, code reader.
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wheeler
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Re: Xsara Keys

Unread post by wheeler »

Only the BSI, engine ECU & key store immo information. BSM & 'code reader' are not matched.

Big question, why did you swap all these parts in the first place??
jopis8
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Re: Xsara Keys

Unread post by jopis8 »

wheeler wrote: 03 Aug 2026, 16:35 Only the BSI, engine ECU & key store immo information. BSM & 'code reader' are not matched.

Big question, why did you swap all these parts in the first place??
My car was in caraccident years ago, and in years of using it without garage, my engine wiring got corroded and i had few short circuits in last couple months.
I tried to buy complete wiring, but in 200 miles arround me, there is no complete wiring on any carscrape that exists here. They all cut wires when they are selling bsi, bsm, and anything else from scrape cars.
So i bought one same (just a year older car), xsara, with same engine, electronics, and everything.
And i switched complete wiring in engine bay, both (one from bsm to all engine components, and second, smaller from bsm to cooling fan and those 3 green relays above radiator).
I have no lexia, i'm only available delphi diagnostic, just to point that.
But i had more 'bad' components in my car, so i swaped them also (radiator fan, little a/c cpu, cabin ventilator...), and i couldnt permanently delete all error codes that i got when i swaped everything.
So i swaped litteraly everything in engine bay, because my engine ecu was previously opened and something was tampered inside, so i wanted to be sure that i have everything from 'slave' car that worked properly.
But i cant get car to start, like i'm missing something, i got key unrecognized error, with both combinations. Only combination that works, is with code reader+keyfob+engine ecu originaly from my car. But like i said, that ecu was opened, and i'm not sure that works properly.
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xantia_v6
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Re: Xsara Keys

Unread post by xantia_v6 »

The thing you call the code reader is just an antenna, it is not coded. So if the original one from your car works keep it in place and just use the BSI, Engine ECU and key from the donor car.
jopis8
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Re: Xsara Keys

Unread post by jopis8 »

xantia_v6 wrote: 03 Aug 2026, 18:21 The thing you call the code reader is just an antenna, it is not coded. So if the original one from your car works keep it in place and just use the BSI, Engine ECU and key from the donor car.
Tnx. I'll try it out on wednesday, hope to get it working....