In a medium skillet cook sausage, onion, and garlic over medium-high heat until sausage is brown, using a wooden spoon to break up meat as it cooks. Remove mixture from skillet; drain on paper towels.
In a medium bowl combine sausage mixture, black beans, tomatoes, cilantro, and chipotle peppers. In a 1-1/2-quart slow cooker mash pinto beans.
Top with tomato mixture and sprinkle with cheese.Cover and cook on low-heat setting for about 4 hours or on high-heat setting for about 2 hours or until bubbly.Serve immediately or keep warm, covered, on warm-heat or low-heat setting for up to 2 hours. Serve dip with lime wedges and tortilla chips.