Trouble code 90BS - N10 [SAM CONTROL UNIT ] the control unit is faulty

I am trying to work out what this fault code relates to on a mercedes sprinter box van 2011 Vehaile has lack of power but i do not think this is a fuel related issue and it will not let me delete fault code to go on test drive to see if the fault returns there cant be a problem with the sam unit i would have thought not 2011 plate vehicle ?

any ideas