ml320 cdi inlet port shut off motor

[jacksonvr6]

Hi a mate of mine has a ml320cdi its the w164 later model with the V6 engine
it has gone into limp mode so has no power like the turbo isnt working i plugged it into a snap-on diagnostics reader and it came up with "inlet port shut off motor M55"
i have searched on the internet and cant find any info on this as it seems to be a problem on the earlier engines and this is the later v6 engine
it is booked in at an independant merc specialistnext week but was wondering if anybody else had any info,ive heard lots of stories about having to have new manifolds etc but im sure its for the earlier engines

[jacksonvr6]

Cheers for the info,
does anyone know where this is situated on the car or has anyone got any diagrams? Might do the job myself

[jacksonvr6]

Cheers for the help (alot more helpfull than another mb forum!!)
i can do most things mechanically but looking under the bonnet of this ml just looses me!! i cant even see the inlet manifold at the mo
like i said the car is going in to an independant specialist monday but i now know what to expect (probably a big bill for my mate)

[jacksonvr6]

cheers, just checked all the fuses under the bonnet and all seem ok is there another fuse box anywhere?
sorry for all the questions!!

[jacksonvr6]

the car went into the garage and has been fixed now it was the motor, all in cost £600, that was 5hrs labour,the motor and had to go on the diagnostic machine twice didnt think that was too bad really?
again cheers for the help