Hello Mikhail.

I haven't touched a GW in over eight months, unfortunately (or should that be:- fortunately) ... and I never did crack this one to my satisfaction.
If anyone has a secret list of the access codes for this little pump, I would be very interested in taking a look at it (purely from an academic interest point of view, of course)!
Meanwhile
Frank has the manual.
But for completeness, let's
link ... and
link again!