Very interesting reading. My 2011 xf 3.0l v6 diesel has only just started showing a gauge error since the main dealer replaced the alternator. Tank is full yet the dash fuel reading shows less then half. Not the most competent mechanic but i refuse to be over charged a second time from the main dealer who told me no issues showed up on their diagnostic check. No engine or acceleration issues so is the general consensus its the connector that needs a clean? (The one inside the fuel tank under the rear seat).