Electronic Engine Controls

The electronic engine controls consist of the:
^ Powertrain Control Module (PCM).
^ Throttle Position (TP) sensor.
^ Idle Air Control (IAC) valve.
^ Engine Coolant Temperature (ECT) sensor.
^ Camshaft Position (CMP) sensor.
- camshaft synchronizer.

^ Crankshaft Position (CKP) sensor.
^ Mass Air Flow (MAF) sensor.
^ Intake Air Temperature (IAT) sensor.
^ Heated Oxygen Sensor (HO2S).
^ Knock Sensor (KS).
^ Vehicle Speed Sensor (VSS).
^ Cylinder Head Temperature (CHT) sensor.

The PCM needs the following inputs to calibrate the engine properly:
^ camshaft position.
^ engine rpm.
^ engine coolant temperature.
^ amount of engine detonation.
^ crankshaft position.
^ air temperature.
^ throttle position.
^ cylinder head temperature.
^ mass air flow.

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:
^ sends the PCM a signal indicating camshaft position used for fuel synchronization.

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

The MAF sensor:
^ sends the PCM a signal indicating mass airflow rate of air entering the engine.

The IAT sensor:
^ sends the PCM a signal indicating the temperature of the air entering the engine.
^ resistance decreases as temperature increases.

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 knock sensor is located on the rear of the LH cylinder head.
^ sends a signal to the PCM indicating engine detonation.
^ if detonation is occurring, the PCM then changes engine timing.

The Cylinder Head Temperature (CHT) sensor:
^ is mounted into the wall of the cylinder head and is not connected to any coolant passages.

The VSS:
^ is gear driven by the transmission.
^ sends a signal to the PCM indicating vehicle speed. For additional information, refer to Automatic Transmission/Transaxle or Manual Transmission/Transaxle.

The Clutch Pedal Position (CPP) switch (manual transmissions only):
^ sends a signal to the PCM indicating clutch pedal position.