NEXON BSVI MCE - SERVICE MANUAL

1.5L REVOTORQ ENGINE 183 B. OVERVIEW Engine Management System Overview Modern engine management systems do a fine job of ensuring that engines run cleanly and efficiently in a wide variety of conditions, they are for the most part reliable and require little or no maintenance. Engine management system Comprises of Electronic Control Unit (ECU), Sensors, Actuators, Wiring Harness and control algorithms, which determine the performance of the Engine as a whole and as part of the vehicle. Electronic Control Unit (ECU) The Electronic control Unit is a 32 bit microprocessor which controls the injection parameters as well as some of the vehicle related outputs such as Fan, AC drivability in gears, EGR etc. The ECU receives input from various sensors located on the engine and the vehicle, and decides the injection quantity, injection timing, number of injections best suited for the engine to work with maximum efficiency and safety. Input to the ECU is received from Crank sensor, Cam sensor, Vehicle speed sensor, Pedal sensor, Rail Pressure Sensor, Fuel Temperature sensor, Coolant temperature sensor, Air mass flow sensor, Boost Pressure and atmospheric pressure sensor, water-in-fuel sensor, pump mounted sensor. Based on all these inputs, the ECU controls all the injectors directly. It also controls the Inlet metering valve on the High pressure pump, Engine cooling Fans, Air conditioning and Exhaust Gas Recirculation (EGR) valve. The injection parameters are corrected for various atmospheric conditions like cold and hot climates and different Altitudes. Corrections are also applied considering engine safety in case of faults and any abnormal overheating. Fault detection is made simple. Faults are recorded in the ECU which makes it easy to be read with the help of a diagnostic tool and to find a solution. Sensors: A sensor is a device that measures a physical quantity and converts it into an electrical voltage which can be read by an instrument or used by some controller for its purpose. Actuators An actuator causes an action (say injector open or close) based on command given by ECU. Wiring Harness Engine Wiring Harness and Vehicle Wiring Harness interface the Engine and Vehicle components to Engine Control Unit.