Electronic Engine Controls

The electronic engine controls consist of the following:
^ Powertrain Control Module (PCM).
^ Throttle Position (TP) sensor.
^ Idle Air Control (IAC) valve.
^ Engine Coolant Temperature (ECT) sensor.
^ Camshaft Position (CMP) sensor.
^ Crankshaft Position (CKP) sensor.
^ Mass Air Flow (MAF) sensor.
^ Manifold Absolute Pressure (MAP) sensor (2.3L).
^ Intake Air Temperature (IAT) sensor.
^ Heated Oxygen Sensor (HO2S).
^ Catalyst monitor sensor.
^ Wheel speed sensor.

The PCM:
^ accepts input from various engine sensors to compute the fuel flow rate necessary to maintain a prescribed air/fuel ratio throughout the entire engine operating range.
^ outputs a command to the fuel injectors to meter the appropriate quantity of fuel.

The TP sensor:
^ sends the PCM a signal indicating the throttle plate angle.
^ is the main input to the PCM from the driver.

The IAC valve:
^ controls bypass air around the throttle plate at low speeds.
^ is controlled by the PCM.

The ECT sensor:
^ sends the PCM a signal indicating engine temperature.
^ resistance decreases as coolant temperature increases.

The CMP sensor:
^ provides camshaft position information which is used by the PCM for fuel synchronization.

The CKP sensor:
^ sends the PCM a signal indicating crankshaft position.
^ is essential for calculating spark timing.

The MAF sensor:
^ uses a hot wire sensing element to measure the amount of air entering the engine.
^ sends the PCM a signal to determine the intake air mass. The PCM will then calculate the required fuel injector pulse width in order to provide the desired air/fuel ratio.

The MAP sensor:
^ measures manifold vacuum and converts it to an electrical signal. This provides the PCM information on engine load.

The HO2S:
^ has the ability to create a voltage signal dependent on exhaust oxygen content.
^ provides feedback information to the PCM used to calculate fuel delivery.

The catalyst monitor sensor:
^ has the ability to create a voltage signal dependent on exhaust oxygen content.
^ provides feedback information to the PCM used to calculate fuel delivery.

The wheel speed sensor:
^ sends a signal to the PCM indicating wheel speed.