Preheat grill on high.
Remove husks and silks from corn.
Brush corn with 2 tablespoons of olive oil.
Place corn on the preheated grill. Cook, turning occasionally, 10 minutes, or until tender.
Remove from heat and cool slightly.
Cut the corn kernels from the cob, and place in a medium bowl.
Add the peppers and onions to the corn.
In a blender or food processor, mix the cilantro, olive oil, garlic, lime juice, sugar, salt and pepper. Blend until smooth.
Stir dressing into the corn salad.