Not able to calculate grand total with dax correctly

[srbs]

Greetings, I have a table of positive and negative numbers,

All of the numbers are summed into rows as follows,

All I want is to have % of total of these lines, where it would divide all these individual codes by total sum of codes <599, to basically see impact of these individual codes to the overall results of codes under 599

What I would like it to look like is 

Code	Grand total SUM	Grand total dax
500	17861649.87	20823336.44
501	2053807.91	20823336.44
504	506468,00	20823336.44
503	366718.61	20823336.44
532	34692.05	20823336.44

Since there are positive and negative numbers in this list, the % of total function in calculation returns nonsensicle percentages, as stated in the 4th collumn

These are the DAX commands I am using,

Grand total SUM = SUMX('power bi test','power bi test'[sum])

Grand total dax = CALCULATE(sum('power bi test'[sum]),FILTER('power bi test','power bi test'[Code]<599))

I also tried replacing the FILTER with ALLSELECTED, same result

This is driving me crazy and already wasted huge amounts of my time,

Can anyone help me with this?

[ERD · Accepted solution]

Hi @srbs , try these measures (almost same, just a little different):

_Grand total SUM = SUM(t[Grand total SUM])

Grand total dax = CALCULATE ( SUM ( t[Grand total SUM] ), t[Code] < 599, ALL ( t ) )

[srbs]

That works indeed, thank you,

I think I solved it aswell on my own with one uneccesary extra step 

= CALCULATETABLE('power bi test','power bi test'[Code]<599),[Grand total SUM]))

Cheers!

[srbs]

And I wanted to mention that I overlooked like 10 different youtube videos on the matter and the solutions work there but not in my dax for some reason