Valve Body. While driving the vehicle, hard shifts occurred; the vehicle check engine light came on and stayed on while the vehicle went into limp mode. I was able to link to the GMC dealer. The dealer was not and would not inspect the vehicle at that time. I was told I needed to leave or return in two for inspection. The left vehicle was inspected the next day and determined as a value body. The GMC dealer found the part in another state and has the part shipped. I installed the part, had the GMC dealer search it, and performed a recall update.