Last week I went out and took my 550D with me to take some pictures. Unfortunately when I switched it on and tried to taka a pic it gave me this:
Err 01: Communications between camera and lens is faulty. Clean the lens contacts.
Just to be sure I had a look but as clean as it can be – I only have the 15-85 EF-S so I never fiddle with lenses.
A colleague of mine brought his 450D with 50 EF lens to the office. After putting on the 50 mm lens my 550D would still give me the Err 01. So it was clearly an issue with the camera and not the 15-85. After putting the 15-85 back on, everything started worked again like nothing had happened.
This behaviour demonstrates that the Err 01 issue is likely to be caused by some software problem, static electricity or something similar.
The camera had been working fine for a whole month in the US, however this was the first time after I was there that I used it again. I’m guessing the electronics might have had a glitch either on the airport during X-ray scanning, or during transatlantic flight…
Anyway, problem solved (for now)