This sounds like a case of dry joints common with french cars , the french like things to be biodegradeable lead free and non violent so use solder manufactured to EU standards but it has a hi alloy content , take a piece of EU solder and put next to a hi lead content one and you will see the EU one is very stiff whereas the hi lead one is softer , dependent on your skill set you just take it out and use decnt solder on all of the connections on the board ,

11 years is trucking on VW call 7 years end of life there are a lot of companies that re solder these ciruit boards and check them ,

If your going to keep it get a board from the breakers resolder all of the connections and then put that one in re do yours and you got a spare one !