My Volvo S40 (06) would not start when I turned the ignition key. I got a message that was somewhat like "Key Error, please try again". I tried with both my keys so it wasn't the key itself. I think I could hear some relay clicking in the on position. I had the same error about a week earlier but then it worked after a few tries and I didn't think more of it, but this time it would not work.
I called the Volvo assistance and the guy they sent put the key into the ignition, turned it fully on and hit it relatively hard about ten times with the handle of a screwdriver, then he turned it to the off position and repeated the procedure.
The car then started. He said that he had fixed this problem on a few Volvos and they seemed to continue working after this, but he could not guarantee anything.
I am not a mechanic (obviously) so I wonder if someone knows what this error could be. Is it just oxidized connectors or is it a symptom of some bigger problem? What can I do about it?