Place the corn directly on the grill grates and cook until charred on all sides, turning frequently to prevent burning. Transfer to the corn to a cutting board and cut the kernels off the cob using a sharp knife. Place the kernels in a bowl and set aside.
Place 1 1/2 cups blueberries in a food processor and pulse until roughly chopped.
Transfer the blueberries to the bowl with the corn. Add the remaining blueberries, onion, jalapeño, lime juice, lime zest and cilantro to the bowl. Toss to combine.
Season with salt and pepper to taste. Serve.
Notes
Can be made up to 48 hours in advance and stored in an airtight container refrigerated.