In August 1979, the first automobiles with Bosch Motronic were in the dealers’ showrooms. This date marks the beginning of a new era in engine control from Bosch: Motronic combined the control of ignition and gasoline injection in one central control unit.
Ignition and gasoline injection have always been among the core competencies of Bosch. Gasoline injection systems were offered from 1952 onwards. The main considerations here were, on the one hand, savings in fuel consumption and, on the other, an increase in performance. Bosch ignition systems for motor vehicles were produced since 1897. The Bosch magneto ignition was the only operationally reliable and technically mature method of igniting the fuel-air mixture. Due to its lower costs, battery ignition came to the fore in the 1920s. These two lines of development came together in the "Motronic" project which Bosch had pursued from 1973 on.

The heart of the Motronic system is an electronic control unit consisting of a microprocessor and a memory. The memory contains a work program with data for determining the injection amount and the moment of ignition.

Sensors provide the microprocessor with information on the amount of intake air, engine speed, crankshaft position as well as the intake-air and engine temperatures for every injection and ignition operation – i.e. over 6,000 times per minute. The sensors are, basically, the air-flow meter, the speed sensors and the temperature sensors. By comparing the program data, the processor calculates the individual requirements for the next injection and ignition operation. Thus the timing of the moment of ignition and the amount injected are, for instance, quite different in the cases of a cold engine to which strong acceleration is applied and a warm engine subjected to even acceleration. For the part-system "ignition" alone, the program data memory stores 4,096 different possible individual moments of ignition.

When series production commenced in Mai 1979, Motronic was able to lead with one of the decisive trump cards of electronic systems. It was, right from the start, absolutely maintenance-free – apart from the spark plugs – and its sturdiness and load capacity were matched to the entire vehicle life. Not without reason had Bosch manufactured many electronic components in its own Reutlingen factory since 1970, for motor-vehicle components are subjected to different loads than in more solid equipment such as mainframe computers or in entertainment electronics. They had to withstand Siberian temperatures of minus 40 degrees Celsius as well as engine temperatures of over 100 degrees Celsius over long periods. They also had to withstand vibrations from the engine and hard bumps caused by poor road conditions.

In order to achieve the desired operating reliability required before series production could commence, test vehicles with Bosch Motronic prototypes covered half a million kilometres.