This all started before the 1950′. As a result,car engines and their faults were diagnosed and repaired by a few gauges and hand adjusted. Hence, by a mechanic. Most automotive systems were done like this.
I remember when I was an apprentice mechanic, in a small British leyland garage in Batley Yorkshire UK. Whenever there was a suspicious engine problem. Then our chief mechanic”Brian” would put a long screwdriver to his ear and the other end to the engine. Hence, listening for any sound that would give him a clue as to what the problem could be?
Naturally, as time went by then cars became more complex and problems became more complicated. Therefore, I remember the middle of the 1960’s . Engine problems became to rely more and more on using diagnostic equipment. Our boss “Tom”leased a massive machine with a video display. Thus, I think that it was made by Tecalamit, but I could be wrong?
Of course, the machine looked massive to me. Wires came out of it from all directions. Subsequently, I never got to learn how to use it, it was deemed as too complicated for an apprentice. The machine was a video display terminal and it was to help us with diagnosing engine problems. As far as i could remember the machine was able to check the engines temperature and vacuum also the oil pressure.
Maintenance-Emissions move on
Later in the 1960’s came the computerized systems. With the introduction of the fuel-injected models of Volkswagen Type 3 cars. Consequently, followed by the sporty 280Z made by Datsun . Following this,in the 1980’s General Motors put its computerized “Assembly Line Diagnostic Link ” into service. Hence, this was to examine error codes with the speed of 160 baud. However, this speed increased to 8192 baud by 1986 along with UART or “Universal Asynchronous Receiver/Transmitter” at half duplex. This type of diagnostics continued until the invention of complete on-board diagnostic packages. Of course that we see today.
The next part follows in this interesting article-