General Motors LLC (GM) is recalling certain model year 2006-2007 Buick Rainier, Chevrolet Trailblazer and GMC Envoy vehicles, and 2006 GMC Envoy XL and Chevrolet Trailblazer EXT vehicles. Fluid may enter into the driver’s door master power window switch module, causing corrosion that could result in a short in the circuit board, causing window switches to become inoperative. Previously, the affected vehicles may have had their master power window switch module treated with a protective coating, instead of having it replaced.