The following soy milks do not contain any chometz ingredients:
Vitasoy San Sui Original Natural soy milk http://www.vitasoy-usa.com/ethnic/sansui_osd.html
Soy Dream Original un-enriched soy milk: http://www.tastethedream.com/media/SDnutri_O.jpg
Anyone for whom it is necessary to consume kitniyos may drink these products. However, because we are unable to verify the kosher for Passover status of the equipment on which they are produced, we recommend purchasing these items before Passover, at which point any traces of chometz would be batul (nullified.