Electronic Engine Controls
WARNING: This page is about a different car, the 2008 Mercury Mariner and 2008 Ford Escape. However, it is still accessible from the selected car via links, so may be relevant.
The electronic engine controls consist of the following:
- Powertrain control module (PCM)
- Cylinder head temperature (CHT) sensor
- Camshaft position (CMP) sensor
- Crankshaft position (CKP) sensor
- Mass air flow (MAF) sensor
- Heated oxygen sensor (HO2S)
- Catalyst monitor sensor (CMS)
- Knock sensor (KS)
- Manifold absolute pressure (MAP) 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 CHT sensor:
- sends the PCM a signal indicating cylinder head temperature.
- resistance decreases as coolant temperature increases. For additional information, refer to ELECTRONIC ENGINE CONTROLS - 2.3L article.
The CMP sensor:
- provides camshaft position information which is used by the PCM for fuel synchronization. For additional information, refer to ELECTRONIC ENGINE CONTROLS - 2.3L article.
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 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 KS:
- is used to detect engine detonation.
- sends a voltage signal to the PCM.
- is able to provide a signal which retards the ignition timing, as necessary.
The MAP sensor:
- measures manifold vacuum and converts it to an electrical signal. This provides the PCM information on engine load. For additional information, refer to ELECTRONIC ENGINE CONTROLS - 2.3L article.