Intake manifold runner control Circuit code P2008

[tipton67]

HI all

I am having problems with my 2006 my s type Diesel going into reduced performance mode I know i have a problem with my one EGR valve the codes i am getting are 

P0407 Exhaust Gas re circ sensor circuit B low there has been a lot written about  i think this can be resolved by either replacement of my preferred option of remapping but the other is 

P2008 Intake manifold Runner control circuit open bank 1

Thuis seems to manifest itself with a Reduced performance mode at intermittant intervals especially after sharp acceleration 

I know there should be a module that controlles this operation but i cannot seem to find it ? any help would be apperciated

Best wishes

Julian