Abhinav ttec4843 report

                             REPORT; inputs ,outputs ,closed loop

• MAP: The Map sensor (Manifold absolute pressure sensor works as a input) is one of the senor used in an internal combustion engine's electronic control system. The engine which uses  map sensor are typically fuel injected. The map sensor provide instantaneous manifold pressure to engine's ECU. The data by ECU is used to calculate air density and determine engine air mass flow, which sends signal to ecu to rich or lean d flow of fuel if needed, or can have less air in the manifold.
  And the relationship between the map sensor and iac is idle air control is that the map sensor determine the air flow and telll ecu and iac determine how much air should be put in air fuel mixture,fuel injector stays open longer if more air is detected.
  
• MAF: MAF sensors (stands for MASS AIR FLOW ) and is to find out the mass of air entering a fuel injected internal combustion engine. The air mass is necessary information which is provided to ECU to balance and deliver the correct fuel mass to engine.Air changes its density as it expands and contacts with temperature and pressure.
  There are two common types of mass air flow sensor 1.Vane meter sensor and 2.hot wire sensor.
  
  
• CKP: A crankshaft sensor is an electronic device used in an internal combustion engine to monitor the position or rotational speed of the crankshaft. This information is used by engine management system to control ignition systems to control ignition system timings and other engine parameters. The crank sensor can be used in combustion with a similar camshaft position sensor to monitor the relationship between the pistons and valves  in the engine, which is particularly important in engine with variable valve timing.so this method is use to 'syncronise'  a four stroke engine upon starting, allowing the management system to know when to inject the fuel.
  Relationship btw input&output:injector,fuel pump relay,pcv.
  
• TPS: A TPS (throttle position sensor)  is used to monitor the position of the throttle in an internal combustion engine. The sensor is usually located at the butterfly spindle so that it can directly monitor the position of the throttle valve butterfly, sensor is  usually potentiometer and depending upon the position it provides the resistance. The sensor signal is used by the ECU as an input to control itz system.the ignition timing and  fuel injection timing are altered depending upon the position of the throttle and also depending upon rate of change of that position.
  Relationship btw input&output: injectors, auxiliary air valve.
  
• CMP: A CMP (stands for camshaft position sensor) sensor provides the camshaft position information to ecu, the cam sensor tells the computer where your cam is in its rotation. The info is used to determine spark timing and fuel delivery and which is used by the powertrain control module for fuel synchronization.
  Relationship btw input&output: injectors , EST.
  
• ECT: An ECT (stands for engine coolant temperature) sensor is a sensor that is screwed into the engine block or cylinder head and is used to determine the temperature of the engine coolant, and the ect sensor is basically a thermistor that changes resistance with temperature . when the ect is high (hotter), the resistance is low and when ect is low(cooler) the resistance is high. The resistance reading is sent to the vechicals pcm/ecm  9 cars on board computer) and can be used to activate emmision control or turn the engine cooling fan on.
  
• O2 SENSOR: The o2 sensor is installed to the exhaust manifold to monitor the excess or free , o2 in the exhaust gases. The O2 sensor contains a zirconia element  which at temperature above 360 degree C produces voltages that depends on the O2 contact with the sensor element compared to the O2 present atmosphere , the outside of O2 sensor has a small vent hole ( beneath the external metal cover of the sensor). so sends the signal to the ecu of amount of O2 gases after the fuel combustion, n which identify  the amount of O2 then ecu decided more or less fuel should be injected,higher voltage means low O2 means running rich  and lower voltage means higher O2 which mean is lean.
  Relationship btw input&output: injectors , EGR.
ACTUATORS:

• INJECTORS:It is electronic controlled valve. It is supplied with pressurized fuel by the fuel pump in your car and it is capable of opening and closing many times per second. they inject fuel into the combustion chamber when the valve opens on the  intake stroke. The injectors are mounted in the intake manifold so that they spray fuel directly at the intake valves. and fuel rail supplies the pressurised fuel to all the injectors.
  
• EGR:  It stands for Exhaust gas Recirculation and open when there is back pressure from the exhaust and recirculate the gas back to combustion chamber.It redirect the gas when it sensez the engine is warm and prevent overheating. warm up the car fast when car is first started.
  
• EST:  It control the combustion timing ,Takes measurements in voltage, It modifies the sparks advance when detonation occur and  also trigger when the distributor works.
  
• FUEL PUMP RELAY:  When the coil is energized you can generally quietly hear the fuel pump buzzing for a few seconds.,Then the fuel pump will come on before the engine has a chance to start up so that the fuel system will be pre pressurized , If the relay has gone bad the fuel pump will never come on and test the continuity with ohm meter when energized.
  
  
• AUXILIARY AIR VALVE:  When car is idle it provide air for the fuel to mix with , is measured in hertz and duty cycle and if this does not work the engine will start running too rich and cut off.
  
  CLOSED LOOP OPERATION:-in this mode of operation the initial fuel injection pulsewidth is determined by the ECU .however , the O2 sensor is now opertional and providing feedback from the exhaust gases which enables the ECU to adjust injection pulsewidth to maintain accurately a 14.7/1 air/fuel mixture . feedback from the MAP and PIP (engine speed) sensors will enable the ECU to adjust spark advances against load.the catalytic converter operates more efficiently in closed loop mode since a chemically correct air/fuel mixture is maintained.

• IDLE MODE OPERATION: the ecu will provide rich mix during idle to ensure that a stable idle is maintained.
  in order to achieve this the engine will be put into open loop mode . which means the signal from the O2 sensor will be ignored.open loop mode will have been selected by the ecu from input signal from the throttle position sensor indicating idle position.
  
• ACCELERATION MODE: This would be selected by the ecu when sudden increase in throttle position are signaled by the TPS and sudden change in pressure from the MAP sensor .In this mode extra fuel is supplied as the ECU increases the fuel injector pulse widths.
  
• DECELERATION MODE : This would be selected by the ecu when sudden decrease in throttle position are signaled by the TPS sudden changes in pressure from the MAP sensor , and excess fuel in the intake manifold .Excess fuel in the intake manifold  would be detected by the O2 sensor. In this mode less fuel is supplied as the ECU decreases the injection pulse width.