won't unlock doors

I have a 2004 Citroen C3 HDI model. Yesterday afternoon I parked & locked it. Later @ night when I tried open the door, I did not respond. I tried opening with a spare key but it still did no open. I've replaced battery on one key but this didn't help. I've also tried opening the doors manually with both key with no luck. Somebody please help.

Hi Nelisiwe


Do you have the original Citroen Radio equipment fitted (CD)?

I've also tried opening the doors manually with both key with no luck

If the door won't unlock by manually turning the key in the lock, you are trying to unlock the wrong car.

Arfur Dent wrote:Hi Nelisiwe


Do you have the original Citroen Radio equipment fitted (CD)?

It's an original factory fitted radio that i bought the car with.

Nelisiwe wrote:It's an original factory fitted radio that i bought the car with.

Oh, there goes my theory. Fitting an aftermarket stereo often causes the same symptoms due to the wiring mix-up.

The reason is that the BSI (the computer which controls the central locking) enter a deep sleep state when there is too much drain on the battery, usually overnight. This helps preserve battery charge for starting the engine, but at a sacrifice of the remote central locking.

If you can get the car unlocked manually, using the key in the 'ignition' and starting the engine usually restores remote operation for the rest of the day, but shuts down again overnight.

You may have something similar?


It may also be worth re-synchronising the keys to the car. There are instructions below
Re-sync Citroen C3 Keys


Keeping the key off the key chain while diagnosing these sorts of problems is important.

Check you can unlock the drivers door manually, start the engine (to silence the alarm), stop the engine and see if the remote locking/unlocking works again. This will help identify if its the BSI sleeping or something else.