i had this fault on my leon tdi its the acc petentionmeter sensor but it happened to me twice on the autobahn both times at over 100mph in the fast line u just lose all power and the acc dont work ie no revving as u press the pedal !
mine was i think where i fitted my boost gauges water leaked down onto the sensor (at the back of the dash above the pedal) i think so might be worth a checking for leaks!!