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
- A/C Signal
- Camshaft Position Sensor (Cylinder Identification Signal)
- Camshaft Position Signal (from Ignition Control Module)
- Data Link Connector (Test Mode Signal, for Self Diagnosis Initiation)
- Differential Pressure Feedback Exhaust Gas Recirculation (EGR) Sensor
- Engine Coolant Temperature Sensor
- Fuel Pump Monitor Signal
- Heated Oxygen Sensors (RH-LH)
- Ignition Diagnostic Monitor Signal (from Ignition Control Module)
- Intake Air Temperature Sensor
- Mass Air Flow Sensor
- Octane Adjust Shorting Bar
- Park/Neutral Position Switch (A/T)
- Park/Neutral and Clutch Pedal Position Switch (M/T)
- Stop Light Switch (Brake On/Off Signal)
- Throttle Position Sensor
- Vehicle Speed Sensor

System Output Devices
- Data Link Connector (Self Diagnosis Function, output to Super STAR II Tester)
- EGR Vacuum Regulator Solenoid
- Fuel Injector
- Fuel Pump Relay
- Idle Air Control Solenoid
- Ignition Control Module (Electronic Spark Advance)
- Purge Solenoid Valve (for Charcoal Canister purge)
- Spark Output (SPOUT) Signal (to Ignition Control Module)
- Torque Converter Clutch Solenoid (A/T only)
- Wide Open Throttle (WOT) A/C Cutout Relay
- 3-4 Shift Solenoid Valve (A/T only)