The EFI-Control-Unit Final Test Station

Electronic engine control has recently been introduced as standard equipment on a domestic passenger car in the form of the Bendix Electronic Fuel Injection (EFI) system. This system is controlled by the Electronic Control Unit (ECU), a sophisticated electronics package the mass production of which required the development of special-process test equipment capable of ensuring necessary levels of performance, throughput, reliability, and maintainability. This paper details the development of one part of the overall test facility, the Final Test Station. The Test Station accepts control units at several stages of production completion and applies to them simulated manifold-vacuum pressures in a computer-directed sequence. The 100-torr (13-kilopascal) pressure steps propagate pressure surges of less than 0.2 torr (26 pascals) back to the source tanks; total system settling time is 0.6 second or less. The station is both highly reliable and easily maintainable, and was human-engineered for the efficient manual loading and unloading of test units. It has reduced per-unit test time by more than 50 percent and has increased shift production to levels that permit us to meet passenger-car requirements.