First of all, no spaces after commas.
That's not what the example on the website says. But the engine takes the spaces out anyway.
And why don't you include T and L if you're going to have S and G?
Because T and L only give 1/2 miles (M&M).
Thirdly, try splitting up, as others have suggested. Do H and M separately (like you'd do Y and B).
As I said I had to take out G. G seems to be not OK for this routing. This begs the question why it is not ignored by the engine if it can't find any G. Would be to simple, I guess.