Newly acquired Vehicle, no remote locking.

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Matheu
Posts: 6
Joined: 03 Jun 2018, 15:22
x 2

Newly acquired Vehicle, no remote locking.

Post by Matheu »

Hello all,

I've recently purchased a Citroen Xsara Picasso 1.6 Hdi on a 54 plate, which came with one key, however the PCB inside the key has clearly been damaged as it looked like what l recognise as water damage, not only that but one of the button switches is gone...hence looking for a new PCB and outer shell casing. (its the two button type key)

I know I can pick up replacement keys from certain places that have the key blank, casing and PCB sold as one unit from which I can transfer the key blade and the little black chip... so at this point I would have a new looking working key as far as using the key to unlock the doors and be able to start the car, but here comes my issue.

Still no remote control lock/unlock, I've seen different videos on how to do it and getting different solutions each time, some say that you still need a working fob, some say that you need to lower the front windows and disconnect the battery for a bit, and others that just say put the key in the ignition and click over once and then press a button for 10 secs and then take the key out, and its done...

I know to not always trust the likes of Youtube, so thought by coming here, I'd get a more of a reliable answer.

If someone who knows for sure, exactly how its done I'd be so grateful.

Many thanks.
¬Short version, the key (or transponder chip) is programmed with the car (as the key works) but key needs to be synchronized to the car to allow remote locking.

ozvtr
Posts: 58
Joined: 13 Oct 2020, 01:11
x 8

Re: Newly acquired Vehicle, no remote locking.

Post by ozvtr »

To re-synchronize the transmitter is the last option you mentioned. Turn the ignition to on and press one of the buttons. If you have the owners manual the procedure is in there.
It's possible the transmitter is simply broken. The ignition transponder chip works independently of the central locking transmitter. So, just because the car starts doesn't mean the central locking transmitter is OK.
You could try replacing the buttons on the PCB, they can fail. Replacement buttons are available on EBay and require moderate soldering skills.

Sorry, I am not familiar with the Xsara Picasso. In 2004/2005 the electronics in Citroen cars were based on either the VAN BUS or CAN BUS systems. Which system you have will determine how you go about getting another transmitter for the central locking. If the stock radio is still installed, the CAN BUS radios had a row of silver buttons along the bottom (RD4 radios). The VAN BUS radio buttons were black (RD3 radios).
If you have a CAN BUS car, the replacement key fobs on EBay will work, but you will need access to a LEXIA machine (or equivalent) to code it in. A good locksmith or auto locksmith will have the keys and skills to give you a working transmitter too.
If you have a VAN BUS car, oh boy, only a brand new key from Citroen will work! 110 pound, just for the key! Again, you will need access to a LEXIA to code it in. Dealers will charge you extra for that.

wheeler
Posts: 4737
Joined: 21 Sep 2002, 19:07
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Re: Newly acquired Vehicle, no remote locking.

Post by wheeler »

ozvtr wrote:
08 Apr 2021, 11:56

Sorry, I am not familiar with the Xsara Picasso. In 2004/2005 the electronics in Citroen cars were based on either the VAN BUS or CAN BUS systems.
No full CAN was ever on the Xsara Picasso.
They were comfort VAN only till 2002 then changed to VAN/CAN till the end of production.

Matheu
Posts: 6
Joined: 03 Jun 2018, 15:22
x 2

Re: Newly acquired Vehicle, no remote locking.

Post by Matheu »

Thank you for your replies, I looked in the owners manual but I must have gone past it as I didn't notice it anywhere. I've taken my key apart and on the PCB is 73373067C and looking online I can get them fairly easy, they also physically look identical as well, soldering is an option as well and I'm quite happy to tinker with pcb boards However I don't know how long the remote locking hasn't been working for.... My main concern was attempting to do it and somehow messing up the little black transponder chip rendering the car a giant paper weight haha

I'll let you know how it goes.

ozvtr
Posts: 58
Joined: 13 Oct 2020, 01:11
x 8

Re: Newly acquired Vehicle, no remote locking.

Post by ozvtr »

Matheu wrote:
08 Apr 2021, 15:34
I've taken my key apart and on the PCB is 73373067C and looking online I can get them fairly easy, they also physically look identical as well,
Unfortunately the Chinese knock-off transmitters wont work in your case. Wheeler has pointed out that your car is VAN BUS. Irrespective of what the sellers say, or what the keys look like, they are only CAN BUS compatible, they wont work! If you want to know why, I have a blurb in this post;
viewtopic.php?p=674404#p674404
Matheu wrote:
08 Apr 2021, 15:34
soldering is an option as well and I'm quite happy to tinker with pcb boards However I don't know how long the remote locking hasn't been working for....
Buying second hand cars is a mine field. Particularly if they have had multiple previous owners. The things that owners do (or allow to happen) to their cars is bizarre!
Auto locksmiths have a device that can scan the 433Mhz frequency that the transmitters work on and tell you if it's transmitting "something". Without some form of indicator, you have no idea if it's even working at all.
I think replacing the buttons is your next best bet and the only thing you can do without "seeking professional help". :lol:
Matheu wrote:
08 Apr 2021, 15:34
My main concern was attempting to do it and somehow messing up the little black transponder chip rendering the car a giant paper weight haha
Believe it or not, the transponder chips are fairly easy to code into the car and are cheap to buy. It's the @$#&ing central locking system that's a pain. Short of loosing the chip (not that hard) the user cant really stuff things up.
Locksmiths can "clone" the transponder chip to produce another key to start the engine. However they need a working chip. There is nothing they can do about the central locking transmitter. Only a brand new key from Citroen and/or your old (working) transmitter will work.
In the documentation you got with the car you might have gotten a credit card sized, card with "Citroen" written all over it and a key symbol on it? If you have it, that contains the 4 digit alpha-numeric code for coding in a transponder to the engine ECU. You can get this code from Citroen but you will have to pay for it.
Again, all of this presupposes that you cant get your transmitter working.

Matheu
Posts: 6
Joined: 03 Jun 2018, 15:22
x 2

Re: Newly acquired Vehicle, no remote locking.

Post by Matheu »

ozvtr wrote:
09 Apr 2021, 09:36
...............
I think replacing the buttons is your next best bet and the only thing you can do without "seeking professional help". :lol:
Thank you for your reply, as a result I have microswitches on order as well as a front shell, my key blade seems to be fixed onto the back section (no screw hole) ...

I know it may seem daft to ask, but will replacing the switches and trying to resync to the vehicle (key in ignition and hold button for 10 secs) cause any potential problems with the transponder chip failing?

Thanks again.

ozvtr
Posts: 58
Joined: 13 Oct 2020, 01:11
x 8

Re: Newly acquired Vehicle, no remote locking.

Post by ozvtr »

Matheu wrote:
09 Apr 2021, 18:05
I know it may seem daft to ask, but will replacing the switches and trying to resync to the vehicle (key in ignition and hold button for 10 secs) cause any potential problems with the transponder chip failing?
No. You cant "loose" the transponder code without a scan tool. You need to clear the current codes by using the engine 4 digit pin code and a 5 digit access code. So it's pretty hard to do.
Synchronization just resets the rolling code between the car and the fob transmitter. It does not affect the transponder.

Matheu
Posts: 6
Joined: 03 Jun 2018, 15:22
x 2

Re: Newly acquired Vehicle, no remote locking.

Post by Matheu »

Ok, Update..

I think I'm pretty good with soldering, but on the size of a key fob pcb... never again. The tip of my soldering iron just didnt get hot enough and I ended up almost ruining the board completely.. I managed to do one switch perfect, however the other, not so much. I managed to overheat the board and pulled up two of the switch copper pads so had to resort to other measures...

long story short, I cleaned the board and scraped back some of the mask to see the traces so I could see what went where.
My fix was to use a dab of High Viscosity superglue to hold the switch in place, and used something called 'Bare Conductive Electric Paint' to connect up the traces.

Job done, and now my remote locking is working.. :D
Thank you all for your replies, the info and suggestions were gratefully appreciated.