This seems to be the second reported diff failure in a 3C Passat posted on here.

Odd, since the same diff is fitted to several other models, and could be considered bulletproof. It doesn't do a whole lot of work, since the cars it's fitted to are mostly front-drive biased.

Will be the same diff as a Tiguan, just swap the Haldex module over, providing it's not the Haldex module that has failed.

As an aside, the only thing that does actually kill VW diffs is when someone dumps the diff oil, and overfills the Haldex coupling because they haven't sought to work out which drain and fill plugs do what.