2.2L EFI System: Description

NOTE: Information on this system is also covered in the FUEL SYSTEMS section. Additional diagnostic information that relates strictly to the fuel portion of this system can be found in the THROTTLE BODY FUEL INJECTION article.

The computerized engine control system used on 2.2L fuel injected engines controls 3 areas of engine operation. These areas are the fuel system, the ignition system, and the emission control system. In order to control these systems, several engine and vehicle operating conditions must be monitored.

The engine conditions that need to be monitored include: manifold pressure, throttle position, engine temperature, manifold air temperature, exhaust gas oxygen content, and engine speed. Vehicle conditions monitored include vehicle speed and the status (off or on) of several vehicle systems that affect engine load.

The engine control computer consists of 2 separate modules. The logic module processes all sensor inputs and controls all low power output devices. The logic module also controls the power module. The power module controls the injector, ignition coil, and the auto shutdown relay.

Fig 1: Schematic Diagram of Computer, Input Sensors & Output Devices