How to open passenger door with spare key?

[RayJ]

Hi there,
I am struggling to insert key on passenger door of a Citroen C4, 2006.
Which side of the spare key with Citroen logo should be to the left or right? Is this something of any significance?
Thanks in advance

[GiveMeABreak]

It won't make any difference which way you insert the key into the lock. The pattern should be cut so that it locks / unlocks either way it is inserted.

Maybe there is something stuck inside the lock or it has seized up through non-use. Try a little silicone grease in the lock. If you can get the key in, but it won't open the lock, though it is possible the passenger door lock has been changed at some point.

[Paul-R]

If the key won't turn then it's possible that the tumblers inside have seized. This happened some years ago with key barrels on our Xsara as we habitually used the key fob to lock and unlock the car. I managed to get the passenger side key barrel to work by continual spraying in the key slot with WD40 (other fluids are available) and careful insertion of the key with much jiggling to persuade the tumblers to recommence movement.

I never did get the driver's side to work and resorted to swapping and reassembling the two sides over so I could get in the driver's side.