Citroen C3 key Run out of battery

You may need to find out how to reprogram the remote to your particular car.

For reference, on many Ford models (Focus is the one I have), you turn the ignition OFF-RUN-OFF-RUN-OFF-RUN-OFF or so, and then there is a chime. Then you push any key on the remote, and the chime should go off again; then you put it in RUN. Finished. Takes all of 10-20 seconds.

Your model is likely different, so find the particular instructions for your car. But it will probably be something like this.

Depending on your car's model year, you can use the PSA 10S remote programming. Here's what you gonna do:

Gather ALL keys of your car. It's needed to reprogramming ALL of them at once.

Seated inside the car, all doors closed, everything OFF, insert one key on the ignition and turn to ON (without starting the engine). Then, press and hold the LOCK button for 10 seconds. Turn off, remove the key, repeat the procedure with the other keys. Then, after the last one, remove it from the ignition, put all of them on the passenger seat (far from the ignition switch's antenna), wait for 1 to three minutes to wait for the BSI (or ECU) shuts itself down (Some Citroen models pulses the fuel pump when it happens) then open the door. If your car is old enough, it should work. Newer cars theoretically don't unpair. Anyway, if it didn't help, go to a car shop to reprogramming properly.