Thanks.
How would I know whether they had fixed the cause of it (if there is a problem to be fixed), rather than just cleared the code?
This seems to be reporting a problem that occurred sometime since codes were cleared (maybe just once, or many times), and I’m concerned that it might be intermittent. (I haven’t seen it failing to start myself.)
Of course, I suppose it could be a problem that has already been fixed.
As db4690 says, it could be a weak battery, or just the battery having previously been weak due to sitting unused in the dealer’s lot, and it did start when I saw it (despite the low voltage - 11.6 V).