Read the Chevy High-Performance tech article on How to Program an OBD-II Powertrain Control Module.

His truck would suddenly start riding extremely rough, like he was constantly in gravel. He took his Silverado to the dealership multiple times in an attempt to diagnose and correct the problem.

"When GM builds the 6L80E at the factory, it installs a control module directly to the valve body. It houses all the pressure control solenoids, shift solenoids, and the transmission control ...