Why can’t a software issue happen suddenly?

The way I would see it, the first code is telling you that there is a problem in the ECUs’ software. The second code is logged because the same software is not happy with a feedback signal. When you know the software is faulty I don’t see any good reason to trust it. I also don’t see the logic in looking at replacing hardware because its software is faulty.

Its your call, but I would update it before doing anything else.