Mass production of electronic control units for engines

Claim 1

The mass-production method of making the electronic control units of electronic engine control systems for a variety of engine models wherein each engine model requires a corresponding model of electronic control unit which is unique to that engine model, said method comprising the steps of: first, making a plurality of electronic control units wherein each control unit comprises in assembly a central microprocessor integrated circuit which is adapted to carry out, according to a program, calculations used by a control system in controlling an event associated with operation of the engine, a program memory integrated circuit which is programmed with a program adapted to be executed by said central microprocessor integrated circuit in carrying out said calculations and representing a general control equation potentially suitable for any of said variety of engine models, and an unprogrammed programmable read only memory integrated circuit adapted, when programmed, to convert the program of said program memory integrated circuit from a general control equation into a specific control equation which is unique to a specific engine model; and then, once the specific engine model with which each assembled electronic control unit with its unprogrammed programmable read only memory integrated circuit is to be used has been determined, programming the programmable read only memory integrated circuit thereof by means of external programming equipment with specific data unique to the specific engine model with which the eletronic control unit is to be used so as to adapt the program of said program memory integrated circuit thereof from a general control equation into a specific control equation unique to the specific engine model with which the electronic control unit is to be used whereby each electronic control unit is rendered unique to a specific engine model.