General System Description

PURPOSE
The Mitsubishi electronically controlled multiport injection system maintains emission levels and fuel economy within government agency standards, while optimizing driveability. The system consists of an Engine Control Module (ECM), control relay, wiring, sensors and actuators.

OPERATION
The ECM uses an 8-bit microprocessor, random access memory (RAM), read only memory (ROM) and an Input/Output (I/0) interface. The control relay supplies positive current to the purge solenoid, ECM, and injectors. It also supplies current to the fuel pump during starting.

The system also performs self-diagnostic procedures and provides back-up functions if certain circuits fail.

SENSORS/INPUTS
A/C ON-OFF Switch
Barometric Pressure Sensor
Camshaft Position Sensor
Crankshaft Position Sensor
Engine Coolant Temperature Sensor
Heated Oxygen Sensor Front
Heated Oxygen Sensor Rear
Idle Air Control Motor Position Sensor
Idle Position Switch
Intake Air Temperature Sensor
Ignition Switch ST terminal (start signal)
Power Steering Oil Pressure Switch
Park/Neutral Position Switch (A/T ONLY)
Throttle Position Sensor
Vehicle Speed Sensor
Volume Air Flow Sensor

ACTUATORS/OUTPUTS
Air-Conditioner Power Relay
Evaporative Emission Purge Control Solenoid Valve
EGR Control Solenoid Valve
Fuel Injector pulse width
Idle Air Control (IAC) Motor
Ignition Timing Power Transistor
Multiport Fuel Injection Relay
Malfunction Indicator light
Fan Motor Relay And A/C Refrigerant Medium Pressure Switch.
Self-Diagnosis Output