Sporadically over the past few weeks on cold starts, I get the "reduced engine power" warning message. The alert then switches to an "engine control error" but within a minute or so the error messages disappear. The car runs and drives fine. I took it to my local dealer and they of course were unable to replicate the issue and said to bring it back if it happened again. Anyone else experience an issue like this?

 

No, but do you have the ability to put a volt meter on your battery? Maybe check that. Can cause all kinds of weird issues.

 

I'd agree, issues with the battery will cause odd gremlins to appear. Including problems with the BSMS.