In medium bowl, combine pancake mix, cornmeal, sugar, salt and pepper; mix well. Add water; stir just until large lumps disappear. Stir in corn and zucchini.
Heat nonstick griddle or large skillet to medium-high heat (375°F.). Lightly grease hot griddle. For each corn cake, pour scant 1/4 cup batter onto hot griddle, spreading batter to 4-inch diameter. Cook 1 to 3 minutes, turning when edges look cooked and bubbles begin to break on surface. Cook an additional 1 to 2 minutes or until golden brown.
To serve, place 3 corn cakes on each individual plate. Top with sour cream, tomatoes and cilantro.