I'd strongly dispute that. Why not include the spark plugs as well? And the fuel pump? Because... The driven devices, amplifiers etc. are under the control of

I'd strongly dispute that. Why not include the spark plugs as well? And the fuel pump? Because... The driven devices, amplifiers etc. are under the control of the control unit. They are not part of the control unit. They're located in areas subject to much more heat and mechanical stress, and in most cases (ignition coils excepted) are mechanical in function. I'm not talking about the driven devices. Here's a diesel example in video form: https://www.youtube.com/watch?v=4k-G1dMgFUo https://www.youtube.com/watch?v=4k-G1dMgFUo Here's one in gasoline form: https://www.youtube.com/watch?v=5mWlUuEx_xE https://www.youtube.com/watch?v=5mWlUuEx_xE