power train warranty

Do you know what GM considers an ISC (independent service center) when it comes to covering labor warranty on powertrain with 3yr/100k.does it have to come back to dealership for diag, and is labor covered.
Wayne D wrote:Do you know what GM considers an ISC (independent service center) when it comes to covering labor warranty on powertrain with 3yr/100k.does it have to come back to dealership for diag, and is labor covered.