309179238-engine-management-systems.pptx

hdjtccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccctg

1. Engine Management Systems A Brief Introduction Presented by :

2. EMS is a type of electronic control unit that controls the running of an engine by monitoring the engine speed and ensure optimal engine performance . Introduction

3. The Engine Management System (EMS) is responsible for controlling the amount of fuel being injected and for adjusting the ignition timing. Optimum functioning of the EMS assures maximum engine power, with the lowest amount of exhaust emissions and the lowest fuel consumption.

4. EMS SCHEMATIC

5. Sensors Engine sensors in a vehicle are incorporated to provide the correct amount of fuel for all operating conditions. A large number of input sensors are monitored by the engine control unit. Today, sensor technology has become common in modern vehicles. Sensors enhance safety of the people - both on board and on road, control vehicle emissions and make vehicles more efficient. In this article, we will discuss different types of engine sensors used in modern vehicles.

6. Mass Air Flow Sensor (MAF) The MAF sensor (electric sensor) is an integral part of the engine system . It is located in a plastic covering between the engine and the air filter. The purpose of MAF is to calculate the amount of air intake by the engine, in terms of volume and density . For measuring the volume and density of air, the sensor uses either a hot wire or a heated filament. After the measurement, it sends a voltage signal to the computer. With this, the computer can calculate the right amount of fuel needed to maintain the correct fuel mixture for every operating condition. If there is any fault in the MAF sensor, it may result in rough idle, stalling and poor fuel economy.

7. Throttle Position Sensor (TPS) The Throttle Position Sensor (TPS) is a variable resistor attached or mounted on the throttle body and is operated by moving along with the throttle shaft or spindle. The TPS changes the resistances as the throttle opens and closes, and sends a voltage signal to the computer showing the angle or position of the throttle Thus, the TPS causes the Electronic Control Unit (ECU) to use the data to measure the engine load, fuel delivery adjust timing, acceleration, deceleration when the engine is idle or in wide open throttle, and then makes the changes according to the operating conditions. Fuel rate is either increased or decreased to achieve this.

8. The CTS measures the internal temperature of the engine coolant. It also senses the changes in temperature and sends a voltage signal to the Powertrain Control Module (PCM) for determining whether the engine is cold or warming up, is at normal operating temperature or is overheating. Coolant Temperature Sensor (CTS) The Coolant Temperature Sensor (CTS) is a temperature dependent variable resistor located on the cylinder head or intake manifold. The CTS is an important sensor and the operating strategy of the engine depends on the signal it sends. So, it is called the “master” sensor.

9. Oxygen Sensor The oxygen sensor is located on the exhaust manifold. This sensor monitors the amount of unburned oxygen present in the exhaust. When the fuel mixture is rich, most of the oxygen is exhausted during the combustion. So, only a little unburned oxygen will be left out in the exhaust Difference in the oxygen levels creates an electrical potential, which causes the sensor to generate a voltage signal. This helps the ECU to check the quality of fuel mixture to make the changes accordingly. The sensor output will be high if the fuel mixture is rich, and the sensor output will be low if the fuel mixture is lean

10. Manifold Absolute Pressure Sensor (MAP ) The MAP is a key sensor as it senses the engine load. It is mounted on the intake manifold. It monitors the difference between the air pressure in the intake manifold and outside. This sensor responds to the vacuum in the intake manifold and generates a voltage signal accordingly. It then sends the signal to the PCM. The input of the sensor is used for adjusting the fuel mixture and ignition timing, according to the changes.

11. Knock Sensor The Knock Sensor detects engine knock and sends a voltage signal to the engine and the engine uses that signal to control the timing

12. Knocking  (also  knock ,  detonation ,  spark knock ,  pinging   or pinking ) in spark-ignition  internal combustion engines  occurs when combustion of the  air/fuel mixture  in the cylinder does not start off correctly in response to ignition by the  spark plug , but one or more pockets of air/fuel mixture explode outside the envelope of the normal combustion front.

13. Engine Speed Sensor An engine speed sensor is attached to  crankshaft of car's engine and it indicate the speed that crankshaft is spinning. This information is beneficial to control both the ignition timing and EMS.

14. Engine Oil Sensor It measures the oil pressure inside the engine and gives an alert in case of any problem with oil pressure.

15. Crankshaft sensor It is used to monitor the position and rotational speed of crankshaft and these information will be used by the EMS to control the ignition system timing and other engine parameters.

16. Camshaft Sensor The Camshaft sensor determines which cylinder is firing to establish injector synchronization and coil firing sequence in DIS systems then only crankshaft sensor set ignition timing, supply the signal and measure the speed.

17. Multi-point fuel injection In this system each cylinder has number of  injectors to supply/spray fuel in the cylinders as compared to one injector located centrally to supply/spray fuel in case of single point  injection system

18. Electronic Fuel Injection System

19. ADVANTAGES Ease of Control Adaptable to multiple scenarios Very low cost compared to mechanical systems Occupy lesser space-compact engine bay Less complicated design Zero wear

20. AUTO TUNING Software on ECU known as a map New maps can be loaded to ECU [ process known as re-mapping or flashing] Complete access to parameters such as fuel injection quantity, boost pressure, ignition timing, idle speed setting No costly equipment required, laptop, Tuner EMS s/w & ODB cable Plug & play ECU’s with multiple maps available.