Heat oil in a large skillet over medium heat. Stir in onions and celery; cook until just slightly golden. Stir in carrots and garlic; cook until garlic is slightly golden.
Meanwhile, bring water to a boil over high heat. Stir in bouillon, and reduce heat to medium. When bouillon cubes have dissolved, add corn and the vegetables from the skillet. Cook until vegetables are tender. Add water, if necessary. Reduce heat to low, and pour in 1 cup soy milk. Stir soup well, then stir in remaining 1 cup soy milk.
Quickly whisk in flour. Stir in parsley, garlic powder, salt, and pepper. Cook, stirring constantly, until chowder thickens, about 15 to 20 minutes.