I received this code on a Toyota 8FGCU25. I disconnected the plug to the air fuel ratio control while truck was running and it did not change state. If you disconnect the other plugs while running the truck idles rough or dies. I tested the voltage at the plug 1-2, 2-3 and 4-5, 5-6. I am getting 12v to the plug. I was told that these controllers don't go bad, but it all seems to lead to the controller. I guess I'm looking for a second opinion or confirming the problem. It's a $400 part and want to be sure.