Earlier quoted context omitted.
That was after the first 20 years of automotive computers, though, wasn't it, if only barely? WP says, "In the early 1970s, the Japanese electronics industry began producing integrated circuits and microcontrollers used for controlling engines.[6] The Ford EEC (Electronic Engine Control) system, which used the Toshiba TLCS-12 microprocessor, entered mass production in 1975.[7]" Reference [6] says, "First half of 1970…
EEC-1 exists because regulatory uncertainty forced OEMs to build in a place where they could cheaply change the logic around emissions effecting systems. It is a computer in the same way a modern toaster is. Figure 5yr between "developing" and "fielding". And if you ignore the Plymouth Prowler exercises in putting cutting edge tech into low volume models to get practice doing so it adds another few years depending on…
> 1981: General Motors introduced its "Computer Command Control" system on all US passenger vehicles for model year 1981. Included in this system is a proprietary 5-pin ALDL that interfaces with the Engine Control Module (ECM) to initiate a diagnostic request and provide a serial data stream. The protocol communicates at 160 baud with Pulse-width modulation (PWM) signaling and monitors all engine management functions. It reports real-time sensor data, component overrides, and Diagnostic Trouble Codes. The specification for this link is as defined by GM's Emissions Control System Project Center document XDE-5024B.[4][5]
This is still a far cry from modern cars using CAN buses for all kinds of things, but it's at least digital communication over a bidirectional data link. And then OBD-I is from 01988.