I agree with Richard it's rubbish, damp! it would be on and off like a yo! yo! when it first hit the road if it was damp in our climate.
www.peugeot.co.uk click contact us top of page. then either email for quicker phone ask for any tech services or some one who could put you right.
Was that garage a Peugeot dealership? if not I would suggest with an answer like damp you find a Peugeot one.
The machine sounds like a diagnostic machine which should have produced a print out showing the fault did you get one? even a clear no fault reading?
Bob
November 2008