2006 C3 central locking issues

[Orbit Motors]

I purchased a high mileage hero at auction earlier today, a 2006 C3 1.4 HDi.

Despite it having over 160k on it, it drove a lot nicer than the newer Vauxhall with a third of that mileage than I drove TO the auction house to flog. Engine and box are lovely, decent service history and so on.

The only issue I came across was the lack of central locking, which appears to be a bit of a common issue but with varying symptoms.

Specifically, all the doors and tailgate appear to be permanently unlocked, with the exception of the drivers door which can be locked with the blade. Learned the trick to locking the other doors in an emergency via the black cap in the doors themselves which I'll do next time, nothing in the car worth nicking as it stands.

Is this almost certainly a BSI issue? Somehow I'm not convinced a reset is going to solve it, and I've not had chance to get Diagbox on it yet. Is a new (or used) BSI readily available to programme easily via Diagbox or is it not that easy?

Also skimmed over a thread on another forum about separating the BSI and replacing either a faulty relay or just replacing the top half of it entirely, but that sounds like a recipe for disaster if just one thing was to break and could be an expensive mistake.

Any advice welcome! TIA.

[GiveMeABreak]

Is the fob an original?

It sounds like the fob circuitry is not being recognised, so will allow starting but the remote function is not available (before you go tearing the BSI apart). IIRC our C3 only unlocked the driver door with the blade key and not all the other doors as you would expect, so this is normal behaviour.

When I had the battery out charging it I had to lock the doors the same way using the rear covers to manual lock the rear doors and the blade for the driver's door.

If the fob has been replaced with a knock off or a cheap aftermarket version, the circuitry may be the incorrect type for the vehicle to recognise and that may be why it is not being recognised.

[wheeler]

Does the locking work as expected when using the button on the dash? drop the windows down to experiment.
And yes the rest of the car not locking when using the key in the door lock is normal operation on this vehicle.
Have you had the remote checked to see if its outputting a signal?
Does it have a good battery in the remote & is it the right way around?

[Orbit Motors]

The keys appear to be genuine ones however they are both in surprisingly good nick considering the mileage so I wonder if they are replacements from some point. Might be a coincidence that both batteries are dead if I'm lucky then!

Lock button inside the car appears to work properly!

[ozvtr]

The keys appear to be genuine ones however they are both in surprisingly good nick considering the mileage so I wonder if they are replacements from some point.

Being a 2006 car it will be "all CAN-BUS". The cheap knock off folding fobs can be made to work...BUT...there are two types of signal encoding (for the remote central locking). A trap for the unwary! The transponders used to start the car are easy to get to work.

Lets just hope that the batteries are flat/missing from the transmitters. You could also try re-synchronizing them. The procedure is in the owners manual. Pressing the buttons too many times without the car being in range will put the transmitters and car out of sync. Re-synchronizing them is simple.

However, if all else fails, getting a set of "cheap" transmitters/transponders for your car is not that hard. You don't need the blades cut but you will need an automotive locksmith to supply and code the transmitter/transponder combo. That way you are guaranteed that they will work.

NOW, had the car been pre-2005, OH BOY!! You would need a 4th dan ninja hacker or a brand new (from Citroen) set of keys at more than 100 pound each, PLUS, coding!!!!

[Orbit Motors]

Thank you for the gen guys, I shall have a look after the weekend, either way hopefully not too much head scratching. Just hoping I can get it to work before I sell the car to a family friend!

[Orbit Motors]

Quick update on this, tested batteries and unfortunately it appears they are fine. May have to go and have the key fobs tested to see if they are outputting a signal. When I had a closer look at the inside of the key case it had a date marking of 2013 which would obviously suggest it has had a pair of new keys, I find it hard to believe someone put up with it for 10 years so I'm hoping it is still something relatively simple, but haven't got round to investigating much further yet.

[ozvtr]

May have to go and have the key fobs tested to see if they are outputting a signal.

I bet that they are transmitting something, it's just that your car is ignoring it.

When I had a closer look at the inside of the key case it had a date marking of 2013 which would obviously suggest it has had a pair of new keys, I find it hard to believe someone put up with it for 10 years

Just because they were made in 2013, doesn't mean they were bought in 2013.
Do they have the Peugeot and/or Citroen emblems inside? Valeo? Anything to lead you to believe they might be genuine?

By the way, the "HF Module" in the top of the steering column which receives the signals from the fobs, also processes the information from the transponders in the keys. So if the car starts and runs then there is nothing wrong with that.

[Orbit Motors]

Another update on this problem

Finally got around to calling a well-established auto locksmiths out to see if they could help diagnose the issue.

The batteries are good, keys transmitting a signal. He even went to the effort of creating a new fob with the same signal and that didn't work either (but it did start the engine, like the others).

Holding the lock button when inserting the key hasn't worked despite many attempts. He very helpfully managed to pull the Keycode that would have been on the original card that came with the car and has left that with me, so that's something.

Might it be worth reprogramming both keys with Diagbox and then immediately trying the lock button sequence to make the car think they are new keys? Not saying that will work, I'm no expert on the matter.

Failing that, I'm guessing it is a car issue as opposed to a key issue

[Mouka]

Does your car have a shunt fuse? My 2005 C4 had a similar issue. I pulled all fuses (one by one) carefully checking them as I was trouble shooting another issue with engine management system. After I did this I discovered the key fob was not working and not being able to lock/unlock the car. After a lot of head scratching someone informed me the shunt fuse (C4 has it in the glove box compartment) can be put into park or active position and this is very easy to do as they share a common pin. So i checked and fair enough I accidentally put the shunt fuse back in the parking position (used to limit battery drain during transport etc) which cuts power to the central locking module amongst other things. After I put back to active position and did BSI reset including sync of the FOB all started working perfectly again.

[Orbit Motors]

Does your car have a shunt fuse? My 2005 C4 had a similar issue. I pulled all fuses (one by one) carefully checking them as I was trouble shooting another issue with engine management system. After I did this I discovered the key fob was not working and not being able to lock/unlock the car. After a lot of head scratching someone informed me the shunt fuse (C4 has it in the glove box compartment) can be put into park or active position and this is very easy to do as they share a common pin. So i checked and fair enough I accidentally put the shunt fuse back in the parking position (used to limit battery drain during transport etc) which cuts power to the central locking module amongst other things. After I put back to active position and did BSI reset including sync of the FOB all started working perfectly again.

Interesting, might have to investigate that!

[Orbit Motors]

Dragging up an old thread of mine here but anyway...

I sold this car on to someone I know, and despite being aware of the locking issue they now wanted it looking at again.

I've loaned them my C5 while I have a look, so at least I have some time to work on it. So far I have tried:

Testing keys for a signal (working)
Looking for any stored faults in Lexia (nothing applicable)
Using the actuators in Lexia to confirm the door locks and deadlock functions are definitely working (they are)
New 12V vehicle battery (to rule out any bizarre issues caused by low voltage, I did this following the correct protocol)
Confirmed the dashboard locking button works as normal.

I've realised my original theory of replacing just part of the BSI isn't any use anyway as that would appear to only suit Siemens made units. This car has a Valeo BSI.

I have tried several times to synchronise the key fobs to the car in the usual way. Lexia states there are 3 keys associated with the car, but says there is no remote synchronisation for any of them, and doesn't detect any usage of them (despite signal being present from the key).

Am I going to have to bite the bullet and send the BSI away for repair? I've taken the time to remove it from the car and visually it appears okay. The shunt fuse is in the correct position, all other fuses are fine, there is no obvious fuzz or water damage to the board, it looks in very good nick. Even Lexia *says* there aren't any stored faults, but of course that isn't gospel.

Is there anything else that I can try before pi**ing more money up the wall or should I suggest that the new owner sets fire to it?

[GiveMeABreak]

Just for clarification as it's not clear.

There are 2 separate procedures here.
1) Resynchronisation: This is only for fobs that are already paired / programmed to the BSI and is usually required after disconnection of vehicle battery / fob battery / or when the number of offsets has exceeded the allotted number.
2) The actual pairing of the all keys to the BSI - which should only need to be done once - unless a replacement key is required, then the whole lot need to be coded in again with Lexia or equivalent.

The chip in the key / fob is what the key aerial in the ignition barrel reads to unlock the engine ECU.
The electronics on the fob won't work (remote locking / unlocking / guide me home headlighting etc.) if they are not programmed to the vehicle which is part of the original process.

[wheeler]

He even went to the effort of creating a new fob with the same signal and that didn't work either (but it did start the engine, like the others).

Could this be the issue? The one you have may be the wrong type so making one the same may not work either? Did he tell you if he used ASK or FSK type frequency?
I believe this one should be ASK.

[Orbit Motors]

2) The actual pairing of the all keys to the BSI - which should only need to be done once - unless a replacement key is required, then the whole lot need to be coded in again with Lexia or equivalent.

Could this perhaps be my issue? Just to be clear, are you saying that in theory the keys can work (for actual ignition and starting) without the remote recognising the car? The keys are definitely replacements from the originals, so if this is the case I'm wondering if they were never actually programmed in to the BSI.

Is there a step by step guide for programming new keys with Lexia as I find the software clunky at best, and I spent ages looking through all the menu trees yesterday for anything like this and gave up eventually. I've programmed keys using Diagbox which is fairly easy, but this car is presumably too old to use Diagbox on as it only gave me the option of Lexia or Scantool.

Without jumping to conclusions on the ASK/FSK issue, I'm fairly confident that the locksmith should have known as they were from a very well known auto locksmith in the East Midlands who deal with almost all vehicle keys. But, you never know of course! Is there a clear way to tell them apart by looking at the PCB inside the key remote?

Thanks for all your assistance guys.