System Description

The Computerized Engine Control system is built around an Electronic Control Unit (ECU). The ECU is constantly monitoring return signals from various sensor inputs and then responds by opening or grounding an output device circuit within the ECU. As operating conditions change, the ECU makes any needed adjustments in order to maintain optimum performance and fuel economy. If a component or system malfunction is detected, the ECU will illuminate the "CHECK ENGINE" light and record the corresponding trouble code(s) in its memory.

ECU INPUTS
^ Power Supply (Ignition Switch Coupled)
^ Power Supply (Battery Backup)
^ Air Flow Sensor
^ Barometric Pressure Sensor
^ Intake Air Temperature Sensor
^ Engine Coolant Temperature Sensor
^ Throttle Position Sensor
^ Idle Position Switch
^ Motor Position Sensor
^ No. 1 Cylinder TDC Sensor
^ Crank Angle Sensor
^ Oxygen Sensor
^ Vehicle Speed Sensor
^ A/C ON-OFF Switch
^ Neutral Safety Switch (M/T)
^ Inhibitor Switch (A/T)
^ Ignition Switch START terminal (start signal)
^ Power Steering Oil Pressure Switch

ECU OUTPUTS
^ Fuel Injector Pulse Width
^ Idle Speed Control (ISC) Servo
^ Ignition Timing Power Transistor
^ Air-Conditioner Power Relay
^ Fuel Pump Control Relay
^ Evaporative Emissions Purge Solenoid Valve
^ EGR Control Solenoid Valve (California)