State input and output control functions of ECM. Describe the idle speed control with sketch.

State input and output control functions of ECM. Describe the idle speed control with sketch. 
by

1 Answer

Answer :

Inputs and outputs of Electronic Control Module

The inputs of ECM

1. The Ignition (Engine Speed Sensor).

2. Temperature Sensor (Coolant Temperature).

3. Throttle Potentiometer (Intake Air Flow).

4. Throttle Switch (Idle and Overrun, WOT- Wide Open Throttle), Starter Switch.

5. Lambda (O2) Sensor.

6. Pressure Sensor (Manifold Pressure) and other sensors.

The Outputs of ECM

1. Injection Volume Control.

2. Injection Timing Control.

3. Ignition Timing Control.

4. Evaporative Emission Control.

5. Turbocharger Boost Pressure Control (Diesel).

6. Engine / Vehicle Speed Control.

7. EGR Control.

8. Glow Plug Control (Diesel)


Idle speed control system as output function of ECM

image 

The idle speed is controlled by a stepper motor that is operated by ECM as a function of engine speed, load and engine temperature. The stepper motor controls the idle passage size i.e. it controls amount of air entering the intake manifold. The fuel injection is controlled by ECM using electronic fuel injector. Thus air: fuel ratio gets controlled by proper fuel with adequate air flow past the Idle Speed Control valve (that is operated by stepper motor). Stepper Motor: It rotates a valve shaft either in or out. This in turn increases or decreases the clearance between the valve and the valve seat, thereby regulating the amount of air allowed to pass through. The Idle speed control valve stepper motor allows 125 possible valve opening positions. It is located in the air bypass channel around the throttle valve. 


OR


Idle speed control 

While the engine is being started, or operated, the logic module of Electronic Control Module (ECM) will signal the Stepper motor of Idle Speed Control (ISC) valve to provide the easy starting without the operator having to touch the accelerator pedal. 1. When the engine is cold, the logic module will position the AIS motor to provide the correct cold fast idle speed. The ISC valve motor allows more air to flow past the motor plunger into the intake manifold to increase the idle speed. This air flow bypasses the throttle. 2. The ISC valve motor will provide the correct idle speed when the air conditioner is on and required air: fuel mixture when the engine is decelerating. 3. The injection time is extended to provide additional fuel for cold start and during the post-start and warm up phases. The idle speed is controlled by a stepper motor, which is signaled by ECM as a function of engine speed, load and engine temperature. 4. The stepper motor controls the idle passage size to change the amount of air entering the intake manifold. Thus it controls the effective air: fuel ratio. 5. Stepper Motor: It rotates a valve shaft either in or out. This in turn increases or decreases the clearance between the ISC (Idle Speed Control) valve and its seat, thereby regulating the amount of air allowed to pass through. The Idle speed control valve stepper motor allows 125 possible valve opening positions. 

image

by

Related questions

Illustrate idle speed control as an output control function of ECM.

Description : Illustrate idle speed control as an output control function of ECM.

Last Answer : Idle Speed Control as Output function of a ECM: While the engine is being started, or operated, the logic module of Electronic Control Module (ECM) will signal the Stepper motor of Idle Speed Control ( ... control valve stepper motor allows 125 possible valve opening positions.  OR

Write function of canister purge control and idle speed control in S.I. engine.

Description : Write function of canister purge control and idle speed control in S.I. engine.

Last Answer : Function of canister purge control - 1. The purge valve is the part of the vehicle Evaporative Emission Control (EVAP) system. 2. The EVAP system prevents fuel vapors in the fuel tank from escaping ... control is used to prevent engine stall during idle and to allow the engine to run at low RPM.

What is ECM? Explain how fuel injection is controlled using ECM.

Description : What is ECM? Explain how fuel injection is controlled using ECM.

Last Answer : ECM-The ECM is Electronic control module. It evaluates the sensor inputs using data tables and calculations to determine the output of the actuating devices. The ECM processes signals from the various sensors ... (MS) and the fuel flow from the injector increases in relation to the pulse width.

With the help of neat sketch, describe block diagram of Electronic Diesel Control Unit (EDC).

Description : With the help of neat sketch, describe block diagram of Electronic Diesel Control Unit (EDC).

Last Answer : EDC: The ECU determines the correct quantity of the fuel to be injected based on the inputs and the data in the look up table. The fuel input depends on the rack position and thus ECU ... ECU can also protect the engine against overheating by regulating the maximum quantity of fuel delivered.

Describe with neat sketch operation of PCV valve under different engine operating condition to control/ emission

Description : Describe with neat sketch operation of PCV valve under different engine operating condition to control/ emission

Last Answer : PCV Valve: It consists of a spring loaded tapered valve for flow control. The crankcase pressure and manifold vacuum act together to close the valve whereas the spring pressure tends to keep it open.( ... at idle and low speed (c)High speed/Load operation (d)Preventing backfire during cranking  

List three methods of fuel injection. Describe sequential method with suitable sketch.

Description : List three methods of fuel injection. Describe sequential method with suitable sketch.

Last Answer : Methods of petrol injection 1. Sequential fuel injection. (SFI) 2. Grouped fuel injection. 3. Simultaneous fuel injection 4. Continuous injection.  Sequential Injection: Each injector ... to crank/ camshaft position and pulse width, can be optimized for each individual cylinder.

With the help of suitable sketch describe the working of pressure regulator.

Description : With the help of suitable sketch describe the working of pressure regulator.

Last Answer : Working of pressure regulator : The fuel pump provides more fuel than the maximum required by the engine. Fuel not used by the engine is returned to the fuel tank. The fuel rail supplies all injectors. The pressure ... between 2.0 and 3.5 bar and allows excess fuel to return to the fuel tank.

Write neat sketch, describe MPFI system.

Description : Write neat sketch, describe MPFI system.

Last Answer : MPFI system In the port injection arrangement, the injectoe is placed on the side of the intake manifold near the intake port. The injector sprays gasoline into the air, inside the intake manifold. The ... manifold. If there are six cylinders, there will be six injectors as shown in figure.

Describe the working of EGR valve with neat sketch.

Description : Describe the working of EGR valve with neat sketch.

Last Answer : Answer: Exhaust Gas Recirculation Valve (Operation-2 marks, Sketch-2 marks) When the engine is idling, the EGR valve is closed and there is no EGR flow into the manifold. The EGR valve remains closed ... exhaust gas (less than 10% of total) to be supplied into the incoming air: fuel mixture

Describe the construction and working of D-MPFI and L-MPFI with help of neat sketch.

Description : Describe the construction and working of D-MPFI and L-MPFI with help of neat sketch.

Last Answer : D-LMFI System: It is Manifold fuel injection system.In this type, the vacuum in the intake manifold and volume of air by its density are sensed in this type of MPFI system .As air enters into ... intake manifold , the air flow sensor measures the amount of air and sends information to ECU.

Describe the working of fuel injector with neat sketch

Description : Describe the working of fuel injector with neat sketch

Last Answer : Fuel Injector: The injector assembly consists of - i) a needle valve ii) a compression spring iii) a nozzle iv) an injector body When the fuel is supplied to lift the injection ... spring tension and hence the valve opening pressure is controlled by adjusting the screw provided at the top.

Describe construction and working of TBI system with suitable sketch.

Description : Describe construction and working of TBI system with suitable sketch.

Last Answer : Construction and working of TBI system: Throttle Body Injection is an electronically controlled injection system in which an electronic fuel injector injects the fuel intermittently in to the intake manifold ... to calculate the triggering signals for the injectors and other system actuators.

Illustrate with neat sketch the process to control production of NOx in combustion chamber.

Description : Illustrate with neat sketch the process to control production of NOx in combustion chamber.

Last Answer : Method to control NOx: The EGR system is used to reduce the amount of NOx in the exhaust. NOx production increases as the temperature inside the combustion chamber rises due to acceleration or heavy engine loads, ... (less than 10% of total) to be supplied into the incoming air: fuel mixture.  

Describe the idle speed control function of an electronic control module with neat sketch.

Description : Describe the idle speed control function of an electronic control module with neat sketch.

Last Answer : Idle Speed Control System as Output Function of ECM: While the engine is being started, or operated, the logic module of Electronic Control Module (ECM) will signal the Stepper motor of Idle Speed ... speed control valve stepper motor allows 125 possible valve opening positions. OR

State the different types of SI engine combustion chambers. Draw a neat sketch of any one.

Description : State the different types of SI engine combustion chambers. Draw a neat sketch of any one.

Last Answer : 1) T Head Type Combustion chambers 2) L Head Type Combustion chambers 3) F- Head combustion chamber 4) Over head valve or I head combustion chamber 5) Hemispherical combustion chamber 6) Bathtub ... - Head combustion chamber 4) Over head valve or I head combustion chamber

Sketch and Explain F-head combustion chamber.

Description : Sketch and Explain F-head combustion chamber.

Last Answer : In F-head combustion chamber one valve is in head and other in the block. This design is a compromise between L-head and I head combustion chambers. Advantages are : High volumetric ... This design is the complex mechanism for operation of valves and expensive special shaped piston. 

List eight ways of reducing pollution. Explain PCV and evaporative emission system with suitable sketch.

Description : List eight ways of reducing pollution. Explain PCV and evaporative emission system with suitable sketch.

Last Answer : Eight ways of reducing pollution:-  1) Optimize Ignition Advance 2) Use unleaded gasoline & Low sulphur diesel 3) Use leaner air fuel ratio 4) Use exhaust gas treatment devices ex Catalytic ... check valve. The EVAP system is designed to limit maximum vacuum and pressure in the fuel tank.

List four types of combustion chambers used in S.I. engine. Explain any one in detail with neat sketch.

Description : List four types of combustion chambers used in S.I. engine. Explain any one in detail with neat sketch.

Last Answer : Combustion chambers used in S.I. engine:- 1) T - Head 2) I - Head. 3) F - Head. 4) L - Head 5) Divided combustion chamber. 1. T Head Type Combustion chambers.  This ... and therefore more heat loss. 4. Valve size restricted. 6. Thermal failure in cylinder block also. 

Draw neat sketch of pre-combustion chamber and name its parts.

Description : Draw neat sketch of pre-combustion chamber and name its parts.

Last Answer : Fig. Pre-combustion chamber

Draw neat sketch to show TBI system of SI engine and name its parts.

Description : Draw neat sketch to show TBI system of SI engine and name its parts.

Last Answer : Draw neat sketch to show TBI system of SI engine and name its parts.

Explain the working of diesel engine glow plugs with neat sketch

Description : Explain the working of diesel engine glow plugs with neat sketch

Last Answer : Glow plug is an aid for cold starting of a C.I. engine. The self-ignition temperature of diesel is 250°C. For compression ignition, the charge (air + diesel) should reach a temperature of ... plugs is automatically interrupted. But starting may be attempted again as soon as the driver wishes.   

Explain PFI system with neat sketch.

Description : Explain PFI system with neat sketch.

Last Answer : PFI system In the port injection arrangement, the injector is placed on the side of the intake manifold near the intake port. The injector sprays gasoline into the air, inside the intake manifold. The ... of gasoline and air then passes through the intake valve and enters into the cylinder.

Draw neat sketch of swirl type combustion chamber of IDI engine.

Description : Draw neat sketch of swirl type combustion chamber of IDI engine.

Last Answer : Fig. swirl type combustion chamber of IDI engine.

List four types of sensors used in MPFI system, state their locations and functions.

Description : List four types of sensors used in MPFI system, state their locations and functions.

Last Answer : Sr. Name Function Location 1 Oxygen Sensor Measuring the quantity of oxygen in exhaust  Located at inlet and outlet side of catalytic converter 2 Mass air flow(MAF ... the combustion process and supplies signal to the ECU. This sensor is fitted on cylinder block.

State the drawbacks of carbureted (SI) engines on the basis of fuel distribution, emission, power output and fuel consumption.

Description : State the drawbacks of carbureted (SI) engines on the basis of fuel distribution, emission, power output and fuel consumption.

Last Answer :  Drawbacks of carburetted S.I. engine: 1) Fuel distribution- Mal-distribution of charge. 2) Emission- More emissin 3) Power output- Less 4) Fuel consumption - More

Write the functions of actuators

Description : Write the functions of actuators

Last Answer : 1. An actuator is a component of an engine that is responsible for moving or controlling parts of an engine. 2. An actuator requires a control signal and a source of energy. The control ... movement by converting one kind of motion, such as rotary motion, into another kind, such as linear motion

Compare SI and CI engine on the basis of air-fuel ratio, power output, emission and knocking.

Description : Compare SI and CI engine on the basis of air-fuel ratio, power output, emission and knocking.

Last Answer : Parameter SI engine CI engine Air-fuel ratio air-fuel ratio is 14.7:1 air-fuel ratio is 20:1 to 70:1  Power output  Power output is Less than CI engine due ... Knocking take place at the end of combustion. Knocking take place at beginning or start of the combustion. 

Discuss the drawbacks of carbureted SI engine on the base of, Air-fuel ratio, fuel consumption, power output, emission.

Description : Discuss the drawbacks of carbureted SI engine on the base of, Air-fuel ratio, fuel consumption, power output, emission. 

Last Answer : 1) Air-fuel ratio: - As in SI engine Air-fuel ratio varies from 8:1 to 18.5:1 i.e. from 8 kg of air/kg of fuel to 18.5 kg of air/kg of fuel. Richer or leaner air-fuel ratio limit causes the engine to ... 8 kg of air/kg of fuel to 18.5 kg of air/kg of fuel. So emission is more in SI engine.

Illustrate with example of fuel injection as an output control function of ECM.

Description : Illustrate with example of fuel injection as an output control function of ECM.

Last Answer : Fuel Injection as an Output Control Function of ECM: ECM controls fuel injection by calculating A: F ratio needed for engine. Engine requires different air fuel ratios while cranking, warm- up, idle, ... open, allowing enough air into the engine for start and idle (Throttle body valve is closed).

What is diesel smoke? State two methods to control diesel smoke.

Description : What is diesel smoke? State two methods to control diesel smoke.

Last Answer : Diesel smoke: Smoke is defined as visible products of combustion, is due to poor combustion. It originates early in the combustion. Rich fuel-air mixture & at pressures developed in diesel ... manifold. This shortens the delay period- curbs thermal cracking which is responsible for soot format

Draw a labeled block diagram of CNG conversion Kit. Describe it’s working

Description : Draw a labeled block diagram of CNG conversion Kit. Describe it’s working

Last Answer : Working of CNG Kit: The Sequential Injection system still has a high pressure tank, filler, filter and regulator, the regulator is different in that it puts out a steady pressure as opposed ... , natural gas temperature sensor and coolant temperature sensor to operate and control the system.  

Describe the working of high pressure fuel pump.

Description : Describe the working of high pressure fuel pump. 

Last Answer : Working: Downward motion of plunger: The safety valve at the inlet opens if the pre-supply pressure of fuel exceeds 1.5 bars and fuel comes and fills the chamber till the plunger moves up to BDC. ... . A constant pressure of about 1400 to 1600 bar is maintained in the common rail. 

Describe air fuel- ratio requirements for diesel engines at no load to full load.

Description : Describe air fuel- ratio requirements for diesel engines at no load to full load.

Last Answer : Irrespective of load at any given speed, an approximately constant supply of air enters the cylinder. With change in load, the quantity of fuel injected is changed varying the air fuel ratio. The ... engine always designed to operate with an excess air of 15 to 40% depending upon the application

Draw a block diagram of CRDI system and describe its working.

Description : Draw a block diagram of CRDI system and describe its working.

Last Answer : Working of CRDI system: High pressure pump provides high pressure fuel to the common rail. The common rail stores the fuel and maintains a constant pressure in the common rail line (approximately 1500 bars.). ... rate can be modified by controlling the nozzle needle movement. OR

Describe four effects of detonation.

Description : Describe four effects of detonation.

Last Answer : 1. Noise and roughness: Mild knock is seldom audible and is not harmful. When intensity of knock increases a loud pulsating noise is produced due to development of a pressure wave. The ... and combustion chamber wall and this overheating leads to ignite the charge before the passage of spark.

Describe the concept of Gasoline Direct Injection (GDI)

Description : Describe the concept of Gasoline Direct Injection (GDI)

Last Answer : Gasoline Direct Injection (GDI), also known as Petrol Direct Injection. This system is employed in modern two-stroke and four-stroke gasoline engines. The gasoline is highly pressurized, and ... mixtures are much leaner than in a conventional engine and reduce fuel consumption considerably.  

Draw a labeled block of LPG conversion kit. Describe its working.

Description : Draw a labeled block of LPG conversion kit. Describe its working.

Last Answer : Working of CNG Kit: The Sequential Injection system still has a high pressure tank, filler, filter and regulator, the regulator is different in that it puts out a steady pressure as opposed ... , natural gas temperature sensor and coolant temperature sensor to operate and control the system.

Describe DTSI system. Write two advantage of it.

Description : Describe DTSI system. Write two advantage of it. 

Last Answer : DTSI technology provides a combination of the light weight and twice the power offered by two-stroke engines with a significant power boost, i.e. a considerably high "power-to ... winter season & cold climatic conditions or at very  low temperatures because of increased Compression ratio

Describe four properties of gasoline as a fuel for SI engine

Description : Describe four properties of gasoline as a fuel for SI engine

Last Answer : Volatility: volatility depend upon fractinal composition of fuel. Method of measuring volatility has been standardized by ASTM ( American society of Testing Materials) and the graohical representation ... gasoline to improve the gasoline stability during storage by inhibiting the formation of gums.

Describe the working of electronically controlled diesel injection pump.

Description : Describe the working of electronically controlled diesel injection pump. 

Last Answer : Answer: Electronically controlled diesel injection pump: This is similar to conventional pumps, but its injection is controlled by Electronic Control Unit (ECU) which control solenoid valve in the injection pump ... modifies the current to the solenoid valve, to supply fuel as per requirement.  

Describe glow plug. Why and where it is used.

Description : Describe glow plug. Why and where it is used.

Last Answer : Glow Plug: Some diesel engines use an electric heater called glow plug inside the cylinders to heat the intake air and help ignite fuel: air mixture. Glow plug is an aid for cold starting of a ... into the secondary chamber. On D.I engines, the glow element extends into the main combustion chamber. 

List three method of fuel injection. Describe any one.

Description : List three method of fuel injection. Describe any one.

Last Answer : Methods of petrol injection 1. Sequential fuel injection. (SFI) 2. Grouped fuel injection. 3. Simultaneous fuel injection 4. Continuous injection. Sequential Injection: Each injector is ... to crank/camshaft position and pulse width, can be optimized for each individual cylinder.  

Describe any four variable affection detonations.

Description : Describe any four variable affection detonations.

Last Answer : Variable affecting detonations. 1. Temperature : Increasing the temperature of the unburned mixture increase the possibility of knock in the SI engine following are the effect on SI engine ... atmospheric humidity decreases the tendency to knock by decreasing the reaction time of the fuel.

Compare detonation and diesel knock on the basis of (i) Fuel Ignition Temperature (ii) Compression Ratio (iii) Speed (iv) inlet temperature (v) inlet pressure (vi) cylinder wall temperature (vii) cylinder size

Description : Compare detonation and diesel knock on the basis of (i) Fuel Ignition Temperature (ii) Compression Ratio (iii) Speed (iv) inlet temperature (v) inlet pressure (vi) cylinder wall temperature (vii) cylinder size 

Last Answer : Comparison between detonation and diesel knock: Parameter To avoid Detonation in SI Engine  To avoid Diesel knock i) Fuel Ignition Temperature High Low ii) Compression Ratio ... Cylinder wall temperature Low High viii) Cylinder size Small Large

Explain Evaporative emission control system.

Description : Explain Evaporative emission control system.

Last Answer : EVAP system Operation: When the engine is running, stored fuel vapours in fuel tank are purged from the canister whenever the throttle has opened past the purge port and coolant temperature is above 54 °C. ... The EVAP system is designed to limit maximum vacuum and pressure in the fuel tank.   

Explain engine design modification parameter to control emissions.

Description : Explain engine design modification parameter to control emissions.

Last Answer : Methods used for improving the exhaust emission under the engine design modification are 1. Use of leaner air-fuel ratios: The carburetor may be modified to provide relatively lean air fuel ... tolerances and using special type of carburetors. This also includes fuel injection in manifold.  

Explain working of Variable Valve Timing and Electronic lift control (VTEC) system. Enlist its advantage and Drawbacks

Description : Explain working of Variable Valve Timing and Electronic lift control (VTEC) system. Enlist its advantage and Drawbacks

Last Answer : Answer: Working of Variable Valve Timing and Electronic lift control (VTEC) system:- VTEC (which stands for Variable Valve Timing and Lift Electronic Control) is an electronic and mechanical system ... 2) Maintenance cost is high 3) Very complex structure required complicated control system.

List out the methods for evaporation control and explain any one.

Description : List out the methods for evaporation control and explain any one.

Last Answer : Methods for evaporation control:- 1. Charcoal Canister System (for Fuel tank and carburetor float bowl emissions 2. Positive Crankcase Ventilation (PCV) System (for crankcase ... crankcase ventilation performance is optimized, while engine performance and drivability remains unaffected.

Differentiate air fuel ratio between carburetted engine and electronic fuel injection engines control system.

Description : Differentiate air fuel ratio between carburetted engine and electronic fuel injection engines control system.

Last Answer : Sr. No. Carburetted engine Electronic Fuel Injection (EFI) engine 1 Fuel atomization depends upon velocity of air in the venturi. Atomization of fuel is independent of cranking ... occurs in carbureted engine. Equal quantity of fuel is supplied to port for each cylinder

Explain any two engine modifications and two fuel modifications to control emission from gasoline engine.

Description : Explain any two engine modifications and two fuel modifications to control emission from gasoline engine. 

Last Answer : Methods used for improving the exhaust emission under the engine design modification are 1. Use of leaner air-fuel ratios: The carburetor may be modified to provide relatively lean air ... Fuel Volatility: Fuel volatility is compromise of high volatility and low volatility to control the pollution