Nemo Throttle Control problem

[NemoNed]

Hi all,
Newbie here
Nemo 59 plate van
Diving along just cuts out,
Diagnostics check returns P1586
Throttle control issue.
I have problems locating this part on the engine as when I follow the air in take pipe it disappears behind the engine meaning its difficult access.
Could someone give me a pointer to a previous thread or just some common sense answer on how to clean or replace this part.
Thanks in advance.
Ned