The fuel injection system is controlled by a micro computer which is known as the Electronic Control Module (ECM), the information from the sensors that control the engine atmosphere including the intake air mass, intake air temperature, coolant temperature, engine speed as well as the amount of oxygen content in the exhaust. These signals assist in adjusting the fuel injection duration according to the requirement through a mechanism similar to the ECM, which in human body acts like the central nervous system where sensors are like nerves to transfer information to the brain which further evaluates the condition and alters the functionality of the human body. For instance, exhaust manifold built-in
Oxygen Sensor, which measures the content of exhaust gas oxygen, sends a signal to the ECM if the level is incorrect and this causes a fast change in the air-fuel mixture setting. In most cases, if there is a problem with the sensor, then there is a backup circuit that lets the car to remain driveable until there is a resolution. Some of the safety measures include; switching off the power before removing electrical connectors, avoiding wrong battery connection, avoiding impact on EFI and ECM, careful during diagnostic exercise not to cause harm, should not tamper with ECM as it may affect warranty and should ensure water does not get inside the electronic parts during inspection or washing. To carry out the removal of the ECM, there is need to try the following steps; unfasten the negative terminal of the battery, unbolt the lower finish panel and the center console, undo the electrical connectors that are connected to the ECM, unbolt the mounting bolts, then raise the ECM out of the vehicle to install it, by reversing the above stated method.