General System Description

GENERAL SYSTEM OPERATION
The Engine Control System consists of various sensors, switches, and a Powertrain Control Module (PCM). These sensors and switches act as inputs to the PCM.

The sensors and switches (inputs) send the PCM data concerning engine operating conditions. The PCM interprets this data in order to control the various output devices that affect air intake amounts, the amount of fuel injection, fuel injection timing, evaporative emissions, idle-up, deceleration, ignition timing, (A/T) 3-4 shift and torque converter lockup operation. The PCM has varying amounts of control over these (outputs).

By controlling these outputs, the PCM can meet the different operational and driveability needs of the engine as the engine experiences different operating conditions and requirements.

SYSTEM INPUT DEVICES
- Mass Air Flow Sensor
- Intake Air Temperature Sensor
- Throttle Position Sensor
- Heated Oxygen Sensors (RH-LH)
- Camshaft Position Sensor (in Distributor)
- A/C Signal
- Engine Coolant Temperature Sensor
- Stop Light Switch
- Vehicle Speed Sensor
- Park/Neutral Position Switch (A/T)
- Clutch Pedal Position Switch (M/T)
- Fuel Pump Monitor Signal
- Ignition Diagnostic Monitor Signal (Ignition Control Module)
- Differential Pressure Feedback Exhaust Gas Recirculation (EGR) Sensor

SYSTEM OUTPUT DEVICES
- Fuel Injector
- Spark Output (SPOUT) Signal (Ignition Control Module)
- Idle Air Control Solenoid
- Fuel Pump Relay
- Purge Solenoid Valve (for Charcoal Canister Purge)
- Wide Open Throttle (WOT) A/C Cutout Relay
- EGR Vacuum Regulator Solenoid
- 3-4 Shift Solenoid Valve (A/T only)
- Torque Converter Clutch Solenoid (A/T only)