Central Locking Problem [With VIDEO] - Could it be the relay?

[authorleon]

Hi all,

I have citroen 03 C3 SX which I bought a few days ago. The guy told me that the central locking problem is just a fuse. But I think he was just blagging me a little.

So I need to get a battery for the key fob.

But so far the symptoms are such. I can unlock the driver door with the key. If I press the lock button. All the doors lock including the driver door. The child safety lock button is always on even when I press it it does not turn off. It has a yellow light.

We do get out of the car, I have to put down the window and opened the car from the outside. Read on the forum that you could change the BSI. But before doing all of that I just wanted to know that these are the symptoms that pertain to the relay needing to be changed.

Apparently the key for exhibits the same issues as well. If anyone could provide some insight regarding the above symptoms I would greatly appreciated.

[GiveMeABreak]

Try this first:

BSI Reset / Battery Disconnect / Reconnect Procedure

[PaulC5]

Something to be aware of, we had a 2003 C3 and using the fob to lock the doors the first press deadlocked them and a second press left them locked but not deadlocked - this is the opposite to most cars but was in the handbook. If you are locking the doors when in the car using the fob then if deadlocked they will not open from inside.
If the bsi reset does not help have a look to see if any of the wires between the door and pillar are damaged, it may not help but does not cost anything to check.

[ozvtr]

If I press the lock button. All the doors lock including the driver door.

Which "lock button" are you talking about? The fob button or the button in the middle of the dash? I take it you mean the dash button?

1) Can you lock AND unlock the doors from button on the dash?
2) Do ANY of the buttons on the fob work at all? I.E. if you lock the car using the button on the dash, can you unlock the doors with the remote (when you have put a new battery in it)?
3) have you tried the "re-synchronizing keys" section of the users' manual?


There is NO "central locking" from the drivers door! It is ONLY mechanically connected to the door lock mechanism.
If you can lock the car, but not unlock the car from the button on the dash, then there is a relay in the BSI that is unserviceable.
If the fob does not work at all it could be the battery or it could be de-synchronized. In a rare case it might be both buttons in the remote (anything is possible with a used car).

[ozvtr]

Ok, I have read your post a bit closer and from the symptoms, yes, it probably is the unlock relay. You can still try the BSI reset but I don't think it will help. Yes, the door lock relays are notorious for failing.
Hopefully replacing the battery in the fob will bring the remote back to life, but my bet is that it will only lock the doors and not unlock them (if the remote works at all). But one step at a time.

You can't just swap the BSI, it is basically the brains of the car and contains unique information to make your car run.
As you may have already found out the relays are not plug-in. They are soldered onto a circuit board.
The relays are easy enough to find (RS carries them) but you will need skills to de-solder and re-solder them.
The BSI is split into 2 circuit cards. The processor board and the relay/fuse board. Usually, they are just "press fit" through connectors to each other and can be pulled apart. It is possible to fit a relay/fuse board from a donor BSI to your BSI. There are some caveats to that statement, but I wont go into that right now.

Of course a work-around would be to get the remote working and use it to lock the car, then unlock the car the way you are now. Just don't dead lock the car!

[authorleon]

Hi all, sorry for the delay.

I have recorded a video show the issue.



Please let me know. I have a feeling it is the relay. But I want to make sure.

Thank you all

[authorleon]

Hello, anyone please?

[ozvtr]

The button with the symbol of a person on it is the rear doors deadlock only. For child safety. But ALL of the doors in your car are deadlocked anyway! All the doors should unlock when any of the inner door handles are pulled. Except if that door is deadlocked. Technically the definition of deadlocked!
IMHO electric deadlocking is a dumb idea. The rear doors have mechanical deadlocking for child safety anyway!! But that's just my opinion.
I do not know why the light is on permanently. It should come on when (dead)locking the rear doors, and go off when they are un(dead)locked. The fact that they are currently deadlocked may be a clue. The light may not go out until the doors are unlocked?

If the indicators flash when both fob buttons are pushed, then the fob is working properly and the car is receiving the signal.

The rear hatch is never "locked". It is just disabled from unlocking. That may sound pedantic, but it more explains how the system works. So, unlike the doors, there is no "lock" solenoid! Also the unlock solenoid operates on a completely different circuit to the doors.

If the lock button on the dash doesn't unlock the doors, but the indicator indicates locked and unlocked (flashing, locked and off, unlocked) then I would say, given all the other symptoms, that the unlock relay in the BSI is faulty.

[authorleon]

The button with the symbol of a person on it is the rear doors deadlock only. For child safety. But ALL of the doors in your car are deadlocked anyway! All the doors should unlock when any of the inner door handles are pulled. Except if that door is deadlocked. Technically the definition of deadlocked!
IMHO electric deadlocking is a dumb idea. The rear doors have mechanical deadlocking for child safety anyway!! But that's just my opinion.
I do not know why the light is on permanently. It should come on when (dead)locking the rear doors, and go off when they are un(dead)locked. The fact that they are currently deadlocked may be a clue. The light may not go out until the doors are unlocked?

If the indicators flash when both fob buttons are pushed, then the fob is working properly and the car is receiving the signal.

The rear hatch is never "locked". It is just disabled from unlocking. That may sound pedantic, but it more explains how the system works. So, unlike the doors, there is no "lock" solenoid! Also the unlock solenoid operates on a completely different circuit to the doors.

If the lock button on the dash doesn't unlock the doors, but the indicator indicates locked and unlocked (flashing, locked and off, unlocked) then I would say, given all the other symptoms, that the unlock relay in the BSI is faulty.

Thank you.. Right, time to change the relay. Once done. I will provide an update. If anyone know of a GOOD source on how to change the relay, that would be great.

Thank you very much

[ozvtr]

Unfortunately the relay is soldered onto the printed circuit board.
If you have the skills, you have 2 choices. 1) replace the relay or 2) replace the whole PCB that the relay sits in.
Inside the BSI are 2 circuit boards. The processor board and the relay/fuse board. The two boards need to be separated in either case.
Here is a video of the replacement of the relay/fuse board and how to separate the two boards.

If you want to just replace the relay, the Youtuber points out the relay to be replaced.

[authorleon]

Perfect. I will get that done. No problem about the soldering. I have done it before. I just need to make sure I get the right relay.

Relay is a YH119

Does anyone know where you can buy this relay in the UK and not a copy.

I have checked on ebay / amazon. Imported from China.

Thank you all

[ozvtr]

The originals were shi...not good, so how could the Chinese ones be worse??
They (originals) should be available from RS and Element14.

[authorleon]

Hello all, I am still waiting for the relay once it arrives I will upload pictures of the repair.

Thank you all

[authorleon]

Hi all,

What would be the correct procedure to remove the ECU?

I assume:

1. Disconnect the battery
2. Unplug the ECU
3. Solder the new relay one
4. Plugin ECU
5. Reconnect the battery

Just making sure.

[ozvtr]

Prop the bonnet open.
Wind down one window (just in case the car locks).
Close the doors, but don't lock the car.
Wait 60 seconds for the BSI to do "house keeping".
Disconnect the positive terminal. Ensure the connector cant touch the positive terminal accidentally.
When you have done what you need to do, close the doors and connect up the battery.
Wait 60 seconds again and don't touch the car during this time (house keeping).
On some models the rear wiper motor might run after the battery is reconnected, so flip the wiper off the glass before reconnecting the battery.