Islamic society has lasted for about a millenium and a half. Hindu society has laster far longer than that. By your reasoning, both societies must be based on some rather potent truths. And I would have to agree, actually--although I suspect you didn't mean to include either as an example of a "moral code rooted in truth," or as examples of societies based on "absolute Truths."
Yes, I would include both societies as having some founding in absolute truths. I also note that Hinduism is understood by those who understand it deeper in history and spiritual depth as a religion of One G-d, that G-d having many aspects. The trouble is that many hold it or view it as having multiple gods.