Didn't affect driving and no limp mode, so was completely unaware I had this fault code till a random scan .
Then it flagged up a few eml's roughly a month apart which I erased with my new iCarsoft .
Absolutely stumped on this now , as it's been twice to the Merc independent once for a software update to cure as throttle body had an actuation test and was OK but Star suggested a correlation issue and a software update fix .
Still the fault persisted and back it went and Star then found the throttle body to be faulty.
New throttle body , a few days of driving and it's back !