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
- cylinder head temperature sensor
- camshaft position (CMP) sensor
- crankshaft position (CKP) sensor
- mass air flow (MAF) sensor
- intake air temperature (IAT) sensor
- heated oxygen sensor (HO2S) - front
- catalyst monitor sensor - rear
- wheel speed sensor
The powertrain control module needs the following inputs to calibrate the engine correctly:
- crankshaft position
- engine rpm
- engine load (manifold pressure)
- atmospheric (barometric) pressure
- engine coolant temperature
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 idle air control valve:
- controls bypass air around the throttle plate at low speeds.
- is controlled by the powertrain control module.
The cylinder head temperature sensor:
- provides a gauge signal for coolant temperature.
- is mounted on rear of LH cylinder head.
- 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 air flow 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.
The heated oxygen sensor:
- has the ability to create a voltage signal depending on exhaust oxygen content.
- provides feedback information to the powertrain control module used to calculate fuel delivery.
The rear catalyst monitor sensor:
- monitors oxygen content after the oxygen flows through the catalytic converter.
- provides a voltage to the powertrain control module used to calculate catalytic converter integrity.
The wheel speed sensor:
- sends a signal to the powertrain control module indicating wheel speed.