Computers and Control Systems: Description and Operation

The electronic engine controls consist of the:
^ Powertrain Control Module (PCM).
^ Throttle Position sensor (TP sensor).
^ Idle Air Control valve (IAC valve).
^ Engine Coolant Temperature sensor (ECT sensor)
^ Camshaft Position Sensor (CMP sensor)
- Camshaft synchronizer.
^ Crankshaft Position sensor (CKP sensor).
^ Mass Air Flow Sensor (MAF sensor).
^ intake air temperature sensor (IAT sensor).
^ Heated Oxygen Sensor (HO2S).
^ Vehicle Speed Sensor (VSS).
^ Cylinder Head Temperature (CHT) sensor.

The powertrain control module needs the following inputs to calibrate the engine properly:
^ camshaft position.
^ engine rpm.
^ engine coolant temperature.
^ amount of engine detonation.

The throttle position sensor:
^ sends the powertrain control module a signal indicating the throttle plate angle.
^ is the main input to the powertrain control module from the driver.

The engine coolant temperature sensor:
^ sends the powertrain control module a signal indicating engine temperature.
^ resistance decreases as coolant temperature increases.

The camshaft position sensor:
^ sends the powertrain control module a signal indicating camshaft position used for fuel synchronization.

The crankshaft position sensor:
^ sends the powertrain control module a signal indicating crankshaft position.
^ is essential for calculating spark timing.

The mass air flow sensor:
^ sends the powertrain control module a signal indicating mass airflow rate of air entering the engine.

The intake air temperature sensor:
^ sends the powertrain control module a signal indicating the temperature of the air entering the engine.
^ resistance decreases as temperature increases.

The heated oxygen sensor:
^ has the ability to create a voltage signal dependent on exhaust oxygen content.
^ provides feedback information to the powertrain control module used to calculate fuel delivery.

The knock sensor is located on the RH side of the block.
^ sends a signal to the powertrain control module indicating engine detonation.
^ if detonation is occurring, the powertrain control module then changes engine timing.

The vehicle speed sensor:
^ is gear driven by the transmission.
^ sends a signal to the powertrain control module indicating vehicle speed.

The Clutch Pedal Position (CPP) switch:
^ sends a signal to the powertrain control module indicating clutch pedal position.

The fuel pressure sensor:
^ is mounted on the fuel injection supply manifold downstream of the fuel injector.
^ regulates the fuel pressure supplied to the fuel injectors.