Your local filesystem is not a server.
"error codes" from local filesystem access are likely browser-dependent.
Google shows lots of results for this search, though they seem to involve various contexts. But almost all relating to Ajax, which is how JQM normally fetches it's pages.
I'd suggest asking on a Cordova forum, where you are more likely to get an answer. I see solutions suggesting you check for status of 0 with content length of 0 to detect an error.
It would see odd, though, to get errors when you are fetching static files from your app's filesystem. It means you forgot to include a file!
Maybe there is some Cordova plugin to make the filesystem act more like a server.