EGI Control System: Description
The Mazda Electronic Gas Injection (EGI) computerized engine control system monitors various engine/vehicle functions to control engine operation and lower emissions while maintaining good fuel economy and driveability. See Fig 1 and Fig 2 .
The Electronic Control Unit (ECU), through various input sensors, monitors battery voltage, engine RPM, amount of intake air, cranking signal, crankshaft angle, intake temperature, radiator and engine coolant temperatures, oxygen concentration in exhaust gases, throttle opening, atmospheric pressure, gearshift lever position, clutch engagement, braking, power steering operation, and A/C compressor operation. The ECU uses all input information to control spark timing, fuel injection, and output devices.
The ECU has a built-in fail-safe mechanism. If a fault occurs while driving, the ECU will substitute pre-programmed values. Driving performance will be affected, but the vehicle may still be driven.