I just ran a check of the diagnostic codes, for no reason really, but because I was there. I got C0547 04. This is described as an ignition switch circuit fault, along with the statement "Message appears on dashboard. Engine will not start".
However, there is no message, and the engine starts with no problem. The code is not a pending code. So I'm a bit confused. Maybe I just need to keep an eye on the ISM?