Hello,
I have a code 22 on my screen, which is pretty annoying. The right side lamp is working fine (both of them, left too). 
I have already done:
- removed the bulb from the left side: (code 21 come out, which is expected)
- swap the two bulbs left and right side, both working, got error 22 back.
- bought new bulbs, still error 22

What I noticed, sometimes, I don't have error code 22, before I put the bulb with the holder into the lamp, and comes back a little later.
Also noticed the