On my 09 I had the drive by wire light (lightning bolt light) turn on and go into limp mode a few times. I checked the grounds and they appeared to have disintegrated yet the truck is rust free. I added a ground between the transmission and frame, the engine and frame, the body and engine, the battery and frame, and battery and engine. the problem went away and never came back after that. I used dielectric grease on the connections to prevent future corrosion.