XSARA PICASSO CENTRAL LOCKING

[Ian j]

My 54 plate xsara picasso 2.0 HDI central locking has recently stopped working either by the remote key fob or manually via the key,
I can unlock/lock the drivers door manually but the only boot unlocks too,the passanger and rear doors have to be opened from the inside to unlock them!
the lock/unlock button on the dash will lock the doors but when i try to unlock via the same button it wont do it!!
ive recently bought a replacement key fob from ebay and swapped the internal circuit board to the new fob as the rubber buttons fell out the original key fob,if i swap the key blade from the original fob to the new one the immobilser stays on and will not start the engine!!!! is there a link between the key/remote locking fob and immobiliser which may have stopped the central locking working properly??????

[Hell Razor5543]

The reason that the swap did not work (for the immobiliser system) is that there is a separate (from the circuit board) component that looks like a small capsule. This is the immobiliser chip, which is read by the aerial system around the ignition key switch. Turning the key triggers the reader circuit, and if there is not the correct response the immobiliser circuit won't allow the fuel pump to get power. Different fobs hold this capsule in differing locations; on the S2 Xantia it is in the head of the key (where it rotates), whereas on other Citroens there is a slot in the body of the fob, near to the pivot point of a sprung key.
If you have changed the keyfob battery recently you need to 're-introduce' the keyfob to the car. Assuming the immobiliser system is working, with the key in the ignition and turned to position 'M', press and hold a button for a few seconds. This should get the key back into the loop.

[Ian j]

if i keep the key blade in the original fob it starts fine but if i put the key blade in the new fob the immobiliser will not allow the engine to fire....ive been using the old fob and key to start the car and just been using the new fob to lock/unlock the doors using the buttons.....it locks ok but now will not unlock any of the doors but if i use the key on the drivers door it unlocks the door and boot but nothing else??? you dont hear the central locking activate to unlock the other doors even though the hazard lights flash as normal when locking/unlocking........would it work if i tried to 'pair' the new fob to the car????

[Hell Razor5543]

Just to show you what I mean, in the head of the key blade is a cavity for the immobiliser chip;

http://www.ebay.co.uk/itm/1x-for-Citroe ... 5ae87888a0" onclick="window.open(this.href);return false;

While on this keyfob design it is within the main body, in the upper left corner;

http://www.ebay.co.uk/itm/1-x-NEW-3-BUT ... 43bf37ff8d" onclick="window.open(this.href);return false;

This is what the actual immobiliser chip in a key looks like;

http://www.autokeysquad.com/wp-content/ ... 24x745.jpg" onclick="window.open(this.href);return false;

I hope this helps.

[Ian j]

My key fob is like neither of those..it's got a push in key blade?? i've opened both the old fob and the new one and had a look at them both but can only see the battery on the circuit board with the 2 micro switches to operate the remote locking..cant see any immobiliser chip ?!?!?!?
ive unlocked the drivers door with the key,then opened all the doors from the inside then can open them from the outside,locked them using the locking button on the dash and the all locked..pressed the dash button again to unlock them,the icon on the dash shows them unlocked but the central locking dosent make the usual clunk sound and the doors stayed locked!! totally confused as it was working fine until 2 days ago....

[Hell Razor5543]

If you can post up a picture of the key somebody should be able to identify where the immobiliser chip is.

[Northern_Mike]

Does it look like this?



If so, the transponder is a very small, black piece of what looks like plastic. You need to get something small and sharp to pop it out and put it in the replacement key.

[Ian j]

yes thats the one! but i use the old fob minus the battery and circuit board in the ignition to start the car...does the transponder need power from the circuit board and battery thats in the fob?? has the transponder stooped working because ive taken the circuit bord and battery out of the fob???
if i dig the transponder out my old fob,put it in the new one one change the key blades over will i have to 'teach' my car about the new key/fob combination? think its something like insert the key turn one 'click' then hold down the lock or unlock button on the fob for 10 secs? bit wary of changing things too much without advice as its semi working at the moment although not quite right!!

[Northern_Mike]

No you won't. I got a new key cut for my Berlingo which uses the same key. I simply swapped the circuit board and the transponder to the body of the new key and it all worked.

I didn't realise the transponder was separate from the circuit board either. I found that if I could start the car with the new key if the old key was in the car with me. I had to call the key supplier and complain their key wasn't working, that's when I learnt about the transponder and it's location/operation.

[daviemck2006]

Could one get a key cut then tape the transponder bit under the dash or in the steering column? I ask as my newly purchased 206 has only one key, the same as the one I saw pictured.

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[Northern_Mike]

I suppose you could but then anyone who fancies breaking the column lock and driving it away can do so

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[Hell Razor5543]

Could one get a key cut then tape the transponder bit under the dash or in the steering column? I ask as my newly purchased 206 has only one key, the same as the one I saw pictured.

Sent from my GT-I9300 using Tapatalk

I would imagine that if you had the security code you could get a new key cut (with a transponder chip and remote board) and then introduce it to the car.

[Northern_Mike]

The company I used cut my key off two pictures of my existing key I emailed them, then even sent me the key number

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[daviemck2006]

Could one get a key cut then tape the transponder bit under the dash or in the steering column? I ask as my newly purchased 206 has only one key, the same as the one I saw pictured.

Sent from my GT-I9300 using Tapatalk

I would imagine that if you had the security code you could get a new key cut (with a transponder chip and remote board) and then introduce it to the car.

I don't have the code card, no handbooks or service books, just a few old MOT's and a couple of bills.

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[Ian j]

I didnt want to risk damaging the transponder so i put the circuit board in the original fob with the half of the new fob that had the buttons on it... made no difference...car starts fine but the central locking will only lock but not unlock!!grrrrr
makes a good solid locking sound and the lights flash as normal,try to unlock and the hazard lights flash,interior lights come on but sounds like the lock motors make a half hearted attempt to work!! i can unlock the drivers door which seems to unlock the boot at the same time but all the other doors stay locked??